l

Article ID: 1672-6421 (2010)04-383-09

The 69th WFC PaperNovember 2010

Advanced manufacturing technologiesof large martensitic stainless steelcastings with ultra low carbon andhigh cleanl,ness

*Lou Yanchun and Zhang Zhongqiu(Shenyang Research Institute of Foundry, Shenyang 110022, China)

•Abstract: The key manufacturing technologies associated with composition, microstructur'e, mechanicalproperties, casting quality and,'ke,y,process control ~,orlarge ,m,a,rtensitic stainless steel castings are1nnVOlvedin thispaper. The achievements fully satisfied the technical requirements' of the large 700 MW stainless steel hydraulicturbine runner for the Three Gorges Hydropower Station, and become the major technical support fo~ the design andmanufacture of the largest 790 MY'! hydraulic turbine generator unit in the world developed through our own efforts.The characteristics of a new high yield to tensile strength (Ri>o,JRm) ratio and high obdurability mart:nsitic stainlesssteel with ultra low carbon and high cleanliness are also described. Over the next ten years, the letrge martensiticstainless steel castings and advanced manufacturing technologies will see a huge demand in clean ;nergy industrysuch as nuclear power, hydraulic power at home and abroad. Therefore, the new high yield 0 tensile strength (RpO)R

m) ratio and high obdurability rnartensitic stainless steel materials, the fast and flexible manufacturi~g technologies

of large size castings, and new environment friendly sustainable process will face new challenges an'd opportunities.

Key words: large martensitic stainless steel castings; ultra low carbon and high cleanliness;turbine runner arid blade

CLC number: TG 142.71 Document code: A

In1970s, the low carbon martensitic stainless steel(ZG06Crl3Ni4Mo) and associated manufacturing process

were developed in China; using large arc furnace melting andtraditiona'l casting process, the world's largest martensiticstainless steel turbine blades were successfully cast and appliedin the world's largest axial-flow hydraulic turbine generatorunit (capacity of 125-170 MW, installed in the Gezhou DamHydropower Station on the Yangzi River). The net weight of asingle stainless steel turbine blade is 25-40 t; the outline size is8 m x 4 m x 1.8 m; the section size varies between 40-500 mm,see Fig. 1. Since 1981, the 21 hydraulic turbine generator unitswith capacity of 125-170 MW in the Gezhou Dam HydropowerStation on the Yangtze River, have been successfully operatedfor nearly 30 years; this marked that the Chinese manufacturingtechnologies of hydraulic turbine generator units have entered

Male, born in 1963, Ph.D. Prof~!l~~r~ndPresident of ShenyangResearch Institute of Foundry.He~tfl?ullted from ShenyangUniversity of Technology in 1.~~~.1l~fobtained his Ph.D fromChina Academy of Machinery~~i'e~.~~nd Technology in 2006.His research interests mainly focus~~ 'on the special metals andtheir forming process technologies.E-mail: louych@chinasrif.comReceived: 2010-05-06; Accepted: 2010-07-20

the era of stainless steel from 1980s.In April 1992, China launched the Yangtze River Three

Gorges Project; the development of large martensitic stainlesssteel with ultra low carbon and high cleanliness and thelarge 700 MW turbine runner started at the same time. Atthe beginning of this century, the new ultra low carbonmartensitic stainless steel (ZG03CrI3Ni4Mo) and associatedmanufacturing technologies were successfully developedin China. At the same time, the design and manufacturingtechnologies of the runner for the large 700 MW mixed-flowturbine generator unit reached the top rank in the world.

z

5008coNg~

o.;

x8,000 . (4.640) 80

, (5~~800 (t1J1,200)

~~--= ,yI

Fig. 1: The world's largest martensitic stainless steelturbine blade

The 700 MW unit of the Three Gorges Hydropower Stationis the world's largest mixed-flow hydraulic turbine generatorunit. The operating water head is 61-113 m. The stainlesssteel runner of the hydraulic turbine has the largest outerdiameter of 10.6 m, weight of 500 t, and consists of a crown,a ring and 13-15 blades fabricated by casting and welding,see Figs. 2 and 3. Advanced integrated technologies have beenused for the ZG03Crl3Ni4Mo large martensitic stainless steelcastings with ultra low carbon and high cleanliness, including:VOD, AOD refining process; advanced computer solidificationsimulation and casting technology; combination of welding andmachining process of large steel turbine runners; microstructureand mechanical properties control, phase transformationand heat treatment process control of large martensiticstainless steel; thermal stress and transforming stress control;deformation and cold cracking control and so on.

---~----"

Fig. 2: Stainless steel turbine blades for the ThreeGorges Power Station

Fig. 3: Stainless steel turbine runner for the ThreeGorges Power Station

Clean energy is an important and preferential developmentfield in China. By 2020, in China the new installation of capacityof hydropower will exceed 120 GW, among which there areabout 150 large mixed-flow turbine units of stand-alone capacity700 MW similar to the unit of the Three Gorges HydropowerStation, about 150 pumped storage power units with stand-alonecapacity 300-400 MW, and about 150 large through-flow typeturbine generator unit~with stand-alone capacity 30-60 MW; the

Vol.7 No.4

development work on the large stainless steel turbine runner forthe level of 1,000 MW capacity unit will also be canied out. Inthe near future, the preferentially developed 150 large units aloneneed more than 2,000 large stainless steel blades. Accordingly,the large martensitic stainless steel castings with ultra low carbonand high cleanliness have a huge market demand [IJ.

Because large ultra low carbon martensitic stainless steelcastings and associated manufacturing processes have manyadvantages, they are widely used in the clean energy industry.Advantages:(1) High strength and toughness: Rp02 >600 MPa, Rm>

800 MPa, A>18%, Z>50%, AKv>100 J.(2) Good low temperature impact property, fracture

toughness and FATT (Fracture Appearance TransitionTemperature, -173 to -196'C).(3) Good welding, casting and machining properties.(4) Good underwater fatigue resistance, good cavitation

corrosion/erosion and wear resistance.(5) High hardenability and good mechanical properties of

heavy section castings.(6) The defects of martensitic stainless steel castings can be

easily and accurately tested and evaluated by non-destructivetesting methods, and the defects can be easily repaired.The key problem for us to deal with in manufacturing

process is that the ZG03Crl3Ni4Mo (Ni4 steel for short) hassome fatal disadvantages.Disadvantages:(I) Mechanical properties are very sensitive to the variation

in microstructure and chemical composition.(2) Mechanical properties are very sensitive to heat treatment

process control.(3) Phase transformation process is more complicated; stress

and cold cracking are difficult to control.(4) Long manufacturing cycle and delivery leading time.In this paper, the Ni4 steel and the associated key

manufacturing technoiogies used for the stainless steel turbinerunner of 700 MW unit in the Three Gorges HydropowerStation are described.

2 Key manufacturing process oflarge martensitic stainless steelcastings with ultra low carbon andhigh cleanliness (Ni4 steel)

2.1 Chemical composition and cleanlinesscontrol of molten steel

The chemical composition and cleanliness control of themolten steel of martensitic stainless steel with ultra low carbonand high cleanliness are listed in Table 1121•

Compared with the current standards of ASTM, ISO and GB(Chinese National Standard), the Three Gorges HydropowerStation Specification has the highest requirement for chemicalcomposition (by weight): C~0.03% (or C~0.04%),S~0.008%, P~O.028%. Control of Ni and Cr equivalent:

Nic';Creq=0.39-0.45

November 2010

Table 1: Chemical composition and cleaniness of Ni4 steel (wt.%)

Residual elements (";)C(";} Si(";} Mn(";} P(";} S(";} Cr Ni Mo ~- ---.__ .~ - ..._,

ElementsAI V Cu w L

AfJ) 0.06 0.80 1.00 0.035 0.025 11.5-13.5 3.5-5.0 0.4-1.0 0.05 0.50 0.10 0.50B(lJ 0.04 0.80 1.50 0.030 0,010 11.5-13.5 3.5-5.0 0.4-1.0 0.05 0.50 0,10 0.50

C2J 0.04 0.60 1.00 0.028 0.008 12.0-13.5 3.8-4.5 0.4-0.6 0.06 0.03 0.50 0.50D'I; 0.06 0.80 1.50 0.035 0.025 11.5-13.0 3.5-5.0 <1.00

E'l 1.00 1.00 0.04 0.03 11.5-14.0 3.5-4.5 0.4-1.0 0.03 0.50 0.10 0.500.06

Note:CD - Chinese NationalStandard GB6967-2009; @ - Three Gorges Specification;@ - IS011972;@ - ASTM352 356487 743.

Nieq=Ni + 0.5Mn + 30(C+NpJ

Crcq= Cr + Mo + 1.5Si + 5.5Al

Among them, Cr = 12.0%-13.5% is a key and propercontent range. Study showed that with variation of Cr between7%-13.5%, the mechanical properties of the steel maintain inthe same level. But only for CD 10%, the reverse transformedaustenite occurs in microstructure. It is obvious that withvariations of Cr content, the corrosion fatigue resistance, lowtemperature impact property, fracture appearance transitiontemperature and welding property of the stainless steel are. 'fi I d'ff (4-61slgm cant y I erent .In the technical specification of the Three Gorges Hydropower

Station turbine runners, the cleanliness and residual elementcontent of molten steel are specified: [O]~80 ppm, [N]~160ppm, [H]~3 ppm, and the up-limit of [AI] and [V] is specified.Among them, the key manufacturing technologies for largemartensitic stainless steel turbine runner with casting andwelding process are: the control of C < 0.03%, [H] < 3 ppmand the residual [AI] and [V].

2.2 Control of microstructure andmechanical properties

Test on four groups of Ni4 steels named as SF-I, SF-2, SF-3and SF-4, respectively were carried out under different heat-treatment process including normalization (N) and tempering(T). SF-I: N(l,OOO'C) + T(600-650'C), SF-2: NO,OOO'C) +T(500-550'C), SF-3: NO,OOO'C) + T(600-650'C) + T(500-550'C), SF-4: N(l,OOO'C).

(I) The microstructure of Ni4 steel are low carbon lathmartensite matrix + 10%-15% reverse transformed austenite+ o-ferrite «3%), see Figs. 4 and 5. It is seen that a slightchange in double tempering process and microstructure causesyield strength to increase by 90 MPa (an increase of 14%)while keeping other properties the same level.The microstructure of low carbon lath martensite is

dislocation martensite, and the mechanism of phasetransformation is shear process without diffusion; duringthe phase transformation process surface relief and volumeexpansion (face-centred cube •..•body-centred cube) occurleading to phase transformation stress in large martensiticstainless steel castings. If during cooling, large castingsexperience the double stresses - the phase transformationstress due to microstructural transformation and thermal stressdue to the variation of temperature in different sections, thiswill be the main reason causing cold cracking defects in largemartensitic stainless steel castings.The reverse transformed austenite (Fig. 6) has extremely

high thermal stability and mechanical instability, which willresult in significant illfluence on mechanical properties, lowtemperature impact and welding property.Reverse transformed austenite has mechanical instability and

strong ability of deformation strengthening. A simple stress hasno effect on reverse transformed austenite. Under the action ofstrain, strain-induced martenisite phase transformation takesplace. The phase transformation mechanism is: stacking fault•..• face centred cubic •..• close-packed cubic •..• body-centred

Fig. 4: Microstructures of Ni4 steel (SF-i) (RpO.2: 635 MPa, Rm: 810 MPa, A: 24%, Z: 72%. Aky>150 J)

CHINA fOUNDRYVol.7 No.4

Fig. 5: Microstructures of Ni4 steel (SF-3) (RpO.2: 725 MPa, Rm: 815 MPa, A: 23%, Z: 71%, Akv>145 J)

(a) Dark field (b) Bright field

Fig. 6: Reverse transformed austenite

Fig. 7: Relationship between reverse transformedaustenite and true strain

cubic structure. During the deformation process under stress,the reverse transformed austenite changes to martensite whichincreasing the strength and hardness, see Fig.7 [4).

The amount, morphology and distribution of 8-ferrite havedirect influences on mechanical properties, resistance to coldbending, fracture appearance transition temperature and the8-0' transformation during welding process of Ni4 steel.Therefore, it is very important to control of ratio of Ni and Crequivalent to 0.39-0.45 in chemical composition and 8-ferrite<3% in microstructure.(2) The mechaJ,lical properties of various standards and

specifications in the world are presented in Table 2.

17.4

No. RpO.2 Rm As Z AKVHBW Standard

MPa (~) MPa(~) %(~) % (~) J (~)

1 550 750 15 35 50 "';;255 NACE2 550 750 15 35 50 220-290 ASTM3 550 750 15 45 220.-290 ISO4 580 780 18 50 80 220.-290 GB5 580 780 20 55 100 220.-290 Three Gorges

Table 2: Mechanical properties of Ni4 steel

After normalization and tempering, the mechanicalproperties of Ni4 steel used for the Three Gorges stainlesssteel turbine runner are listed in Table 3.It is seen that the Three Gorges Standard has mechanical

property requirements even higher than other standards. Thehigh strength, high ductility and toughness and high impactproperty of martensitic stainless steel with ultra low carbon andhigh cleanliness are due to the high strength and ductility of ultralow carbon lath martensite, the deformation strengthening andextremely high thermal stability of reverse transformed austenite.The mechanical properties of full lath martensite steel under

normalized condition are: Rro.2 940 MPa, Rm 1,000 MPa, A 16%,Z67%, AKV 121-130J, HBW 307-315.Research work on stability under different cooling rates of

normalization showed that the Ni4 steel has extremely highhardenability and good mechanical properties of heavy sectioncastings, as shown in Table 4.

o0.685

12 11.7

o0.609 0.1237 0.2107 0.3969 0.575

True strain

31.135

~ 30,..i 25'2:2 20Vl::Jltl 15Glf:'! 10~&. 5

o

Table 4: Mechanical properties of normalized Ni4 steels under air and furnace cooling

a 1,000 980 15 55

2 a 1,000 975 15 60

3 f 1,000 950 16 71

4 f 1,000 952 15 70

1,100 815 13.5 54.0SF-4

f 1,090 850 14.5 61.5

No. Cooling Rm(MPa) RPO.2(MPa)

Note: a - air cooling, f - fumace cooling

A5(%) Z(%) AKV (J) HBWChemical composition

and cleanliness (wt.%)

169 311 319 C: 0.020 P: 0.004176 317 313 (0): 0.0015 IN): 0.0058171 310 311 Mo: 0.41 AI:0.033169 311 310

136 128 331 335 C: 0.031 P: 0.021(0):0.0077 [N): 0.014

136 145 325 331 Mo: 0.99 AI:0.017

Note

VIF

AOD

The Ni4 steel has very good resistance to cold bending, seeFig. 8. If the chemical composition and microstructure of Ni4steel fall outside the control limits and higher a-Ferrite (>3%)appears in the microstructure, the resistance to cold bendingdecreases dramatically, see Figs. 9 and 10.(3) Low temperature impact toughness, dynamic impact

toughness and underwater fatigue property:FAIT:= -173 to -196.C (7].

Fig. 8: Cold bending tested Ni4 steel samples without crack

Fig. 9: The microstructure of Ni4 steel with 8% 6.ferrite

Fig.10: The cold bending tested sample of Ni4 steelwith 8% 6-ferrite with crack

At loading rate of 35 mIs, critical dynamic fracturetoughness of the Ni4 steel K(:= 240-270 MPa.ml12

, the fractureis fully tough fracture, see Fig. 11. The resistance to crackpropagation and P-S-N fatigue test results of the Ni4 steel areshown in Figs. 12, 13 and 14.

f' 300EIII

~ 240:.{5" 180

~~ 120c:

~~ 60eCii

Time (t)

Fig.11: Relationship between stress intensity factor (K1)and time (t)

CHINA fOUNDRY Vol.7 No.4

1E-3

Fig. 12: Crack propagation rate in the air

1E-3

Gl"0~ 1E-4E5~..•..1E-5{!l

1E-610il K (MPa'm"')

a Specimen 1o Specimen 2A Specimen 3

100

2.3 Phase transformation and heattreatment process control of large Ni4steel castings

Study on the relationship between high temperaturemechanical properties and structure transformation duringheating and cooling of castings can supply theoretical basesfor manufacturing process design of large castings. The hightemperature properties of castings during heating and coolingafter solidification are shown in Figs. 15 and 16191•

The resultsshowed that the instantaneouschange in property andvolumeduring martensitephase transformation is the technologicalreference for solidificationand heat treatment process control. Thetypical heat treatment cycle is shown in Fig. 17.

Fig. 13: The crack propagation rate In the simulatedYangtze River water

o10 X~8 N

6

4

2

o1084 6

_ Xl0''C2

b 8~xcoa.~ 6r:r:.'i

r:r:.' 40xa" 2q;

00

10

100

a Specimen 1a Specimen 2

10ilK (MPa'm"')

1E-6

400,..-------------------,

I.OOO'CT

10 10-+- R~-.- RrI!t

8.A--z 8

bxco 6 6~a.~ x

a"r:r:.'i N

4 4 .q;r:r:.;

2 2

0 010 8 6 4 2 0-Xl0''C

Fig. 17: Heat treatment cycle of NI4 steel

Fig. 15: The variation of mechanical properties of Ni4steel with temperature during heating

Fig. 16: After solidification, the variation of mechanicalproperties of Ni4 steel with temperature duringcooling

10'

• p=50\• p=95\

10'

Paris equation(the length of crack) (mm)

daldN=2. 7326" 10.9(M<f9784

daldN=2.3869" 10.0 (M<)31lllO'

10'

4.63

4.86

ThresholdM., (MPa.m"2)

In the air

Experimentalenvironment

In the simulatedYangtze River water

Fig. 14: P-5.N curve for a average stress of 400 MPa (400MPais the actual measured maximum residual stress forthe large cast and welded turbine runner)

Table 5: Threshold and the results of Parisequation fitting

CT.I = 340-360 MPa (in the air)CT. 1 (CF) = 260-280 MPa (in the simulatedYangtzeRiver water)Results of Table 5 showed that the Ni4 steel has good

underwater fatigue resistance which is reduced by 25%-27%compared with the fatigue in air.

i

November 2010 The 69th WFC Paper ••••------------------_._----------------------Softening annealing at 600-650 'C is a unique annealing

process for large martensitic stainless steel castings, and canentirely replace the high temperature diffusion annealing;then normalization between 1,000-1,050'C+ first tempering;at last, normalization and cooling to the temperature rangebetween Ms-Mf and double tempering.

The purposes of double tempering are:(I) Control HB<255 or increase the ratio of yield strength to

tensile strength (RpO/Rm).(2) Increase the reverse transformed austenite content,

improve mechanical and processing properties.(3) Control phase transformation stress and prevent cold

cracking.(4) Make the manufacturing fast and flexible thus shortening

manufacturing cycle.

2.4 New high yield to tensile strengthratio and high obdurability martensiticstainless steel (Type SF-2)

With AOD and VOD refining processes, and through controlof the composition equivalent, cleanliness and the residualelement content, and the control of phase transformation stress,the ultra low carbon martensitic stainless steel with high yieldto tensile strength ratio and high strength has been successfullymanufactured by using of lower temperature (480-520 'C) heattreatment. In addition to high strength and high hardness, thenew steel also has high ductility, high toughness, good weldingproperty and high resistance to cavitation erosion/abrasion.The microstructure of lath martensite single phase is shown inFig.18.

The main technical characteristics of the Ni4 steel (SF-2):(1) Carbon: C~0.03% (or C~0.04%); Control the element

equivalent and residual element AI, V and Cu.(2) High cleanliness: [0]<60 ppm, [N]<150 ppm, [H]<3 ppm,

S < 0.005%.(3) Lath martensite single phase structure with a-ferrite <3%

which has good mechanical properties.The mechanical properties of high strength martensitic

stainless steel specified by GB and ISO standards are listed inTable 6.

(4) The mechanical properties for new high strength highyield-tensile ratio Ni4 steel are listed in Table 7. It can beseen that Rm~I,Ooo MPa, RPO.2>850 MPa, A~15%, Z~50%,AKV~ 100 J, HBW~300.

(5) The resistance to cavitation and abrasion is improved2-3 times, see Fig. 19(91.

(6) Good resistance to cold bending: samples were bent to90° without cracking, see Fig.20.

(7) Good fatigue resistance property with P-S-N curve is

Fig.18: lath martensite single phase microstructurein Ni4 steel (SF-2)

Table 6: Mechanical properties of high strengthmartensitic stainless steel (min.)

No. Rp (MPa) Rm (MPa) A(%) Z(%) AKV (J) HBW Standards

1 830 900 12 35 35 294-350 GB6967

2 830 900 12 35 333 IS011972

showed in Fig. 21.(8) The steel has been successfully used in the blade of

Kaplan turbine and wicked-gate at home and abroad and in therunner blade of small to medium mixed flow turbine unit inChina; and has been also used in heavy section castings suchas the large mechanical arms, large jack catch and so on.

2.5 Casting and combination weldingtechnologies of the 700 MW hydraulicturbine generator unit stainlessturbine runner for the Three Gorgeshydropower station

The computer simulations of casting filling and solidification

SF-2

Table 7: Mechanical properties of Ni4 steel with high strength and high yield-tensile ratio

Materiall Rm (MPa) RpO.2 (MPa) A(%) Z (%) AKV (J) HBS RpO.JRm

1,100 895 18.0 64.0 137 127 337 0.82

1,100 895 18.5 65.0 114 136 333 0.82

1,100 905 17.5 64.0 125 119 335 0.82

1,100 920 17.0 63.5 136 114 337 0.84

Vol.7 No.4

Empty1~0913121216111910239268301336315~0U~3~725115~58

Fig. 20: Cold bending testing (SF-2)

400 r-----------------,

• p=50%• p=95%

Fig. 22: Temperature field of the Three Gorges' turbineblade casting

DlspY1m)

Empty.0.0207'0.0167.0.0126'0.0086.0.00~5'0.0005.0.0035• 0.0076.0.0116• 0.0157.0.0197.0.0238.0.0278.0.0319.0.0359

x~

Fig. 21: P-S-N curve with average stress of 400 MPa

process, temperature field, stress field, deformation andporosity defect prediction for the crown, ring and bladecastings of the Three Gorges Hydropower Station areillustrated in Figs.22-23 [IOJ•

The Ni4 steel castings with ultra low carbon and highcleanliness have high cleanliness, (O)~80 ppm and (S)~50 ppm,and have very good fluidity and filling ability, thus benefitingthe surface and internal quality of castings.The Ni4 steel castings with ultra low carbon and high

cleanliness contain [C]~O.03% and [H]~3 ppm, andhave very good welding property, which is an importanttechnological promise for the quality of Three Gorges turbinerunners fabricated by large martensitic stainless steel castings

~ 300

6Q)

"::>~ 200E'"'"'"~iii 100

10' 10'

N,

10' 10'

Fig. 23: Deformation field of the Three Gorges' blade

(crown, ring and blade) and combination welding.

2.6 Short leading time - Fast and flexiblemanufacturing technology

Improving quality, reducing manufacturing cycle, decreasingconsumption and using environmentally friendly technologieswill strengthen our nation's global competiti veness andsustainable development. Thus we should make improvementin the following aspects:(1) Simulation of cooling curve of large castings within the

mould;(2) Cooling process within the mould and knock out process;(3) Heat treatment process of castings;(4) Welding and finishing process;(5) The cleanliness and inclusion defects of molten steel;(6) Advanced casting technology;(7) Co-current engineering and simultaneous design.

3 Conclusions(I) The composition, mechanical properties, casting

quality and associated manufacturing technologies of thelarge martensitic stainless steel castings with ultra low

390

November 2010

carbon and high cleanliness fully satisfy the technicalrequirement of the stainless steel turbine runner forlarge hydropower generator unit, and offer the technicalsupport for achieving world advanced level in design andmanufacturing of large hydraulic turbine generator unit withcapacity above 700 MW.(2) The preferential development in clean energy such as

hydropower, nuclear power and so on, creates a huge marketdemand for ultra low carbon martensitic stainless steel in thenext ten years. Therefore, high yield to tensile strength ratioand high obdurability martensitic stainless steel with ultra lowcarbon and high cleanliness, the application of fast and flexiblemanufacturing technologies for large martensitic stainless steelcastings, and the manufacturing technologies for low carbon,sustainable economic development will face new opportunitiesand challenges.

References

(1) China Machinery Industry Federation (CMIF). AcceptanceReport on Complete Devices of China Three Gorges Project.2006. (in Chinese)

[2) Institute of Metal Research Chinese Academy of Sciences(IMR). Martensitic Stainless Steel Casting Specification for 700MW Hydropower Turbine of Three Gorges Project, 2008, 7. (inChinese)

The 69th WFC Paper ••••

[3]. Zhang Zhongqiu, Lou Yanchun, Li Xinya. Advances in Researchof Nitrogen Contained Stainless Steels. In: Proceedings of the65th WFC, Korea, 2002.

(4) Zhang Zhongqiu, Li Xinya. Phase Transformation Controllingand Stress Analysis for Large Blades of Mantensitic StainlessSteel. In: Proceedings of the 57th WFC, Osaka Japan, 1990:222-228.

[5) Lou Yanchun, Zhao Fangxin, Yu Bo. Effect of Variation ofChromium on the Characteristic and Regulation of HeatTreatment for Cr-Ni Hydraulic Turbine Material. Foundry, 2004, 5:345-349. (in Chinese)

[6) Lou Yanchun. New Martensitic Stainless Cast Steel with LowCarbon for Hydraulic Turbine ZG06Cr10Ni4Mo. Foundry, 2005,11: 1073-1075. (in Chinese)

(7) Mahnig F, Rist A, Walter H. Strength an9 Mechanical FractureBehaviour of Cast Steel for Turbines. Water Power, 1974, 10:338-343.

(8) Wang Zhi, Zhang Zhongqiu. Relationship between Compositionand Properties of Low Carbon Fe-Cr-Ni Matensitic StainlessSteel. In: Proceedings of the 59th WFC, Sao Paulo, Brazil, 1992:153-159.

[9) Lou Yanchun, Zhao Fangxin, Yu Bo, Wang Jingcheng, XiongYunlong, Yang Yuntao. Electrochemical Corrosion and CavitationErosion Behaviors of Cr-Ni Stainles~ Steel as HydraulicTurbine Material. Journal of Chinese SoCiety for Corrosion andProtection, 2005, 5: 312-315. (in Chinese)

(10) Wu Ying. Study of Martensitic Stainless Steel Blade Castingfor Large-Sized Water Turbine. Foundry, 2009, 8: 820-822. (inChinese)

(The paper was presented at the 69th World Foundry Congress (WFC). Hangzhou China 2010, republished in ChiAa Foundry with theauthor's J.dndpermission). , .

CHINA FOUNDRY Vol.7 No.4

Energy conservation and emissionsreduction strategies in foundryindustry*Li Yuanyuan\ Chen Weiping\ Huang Dan2, Luo Jie\ Liu Zhe\ Chen Yongcheng3,Liu Qiping4 and Su Shifang5

(1. School of Mechanical & Automotive Engineering. South China University of Teclznology, Guangzholl510640. China; 2. School ofMaterials Science and Engineering. Henan Polytechnic University, Jiaozuo 454003. China; 3. Zhongtian Chllangzlu/ll Ductile Iron Co.•Ltd., Foshan 528313, China; 4. Shaogllan Foundry and Forging Group, Shaogllan 512031, Chinn; 5. Shenyang Research Institute ofFoundry, Shenyang 110022, China)

Abstract: Current energy conservation and emissions ~educ.!ionstrategiel'; in iro~and steel indust!)' werereviewed.Since found~ indust~ is one of the rnajorsourceof ~nergyC()nsumR.tionand pollutionemi~sion (especiallyCO2). issues concerning energy-savingand~missi~n-reduction hfY~ been r~is"edbygov~rnniel1t~ ~ancltheindust~. Specialists from around theworld carried out niultidimensi9ralan~I'yses ard evaluation on,the' P?tentialsin energy conservation and emissions reduction in iron and steel industry,andp'r~posed various.kinds gfanalyzingmodels. The prima~ measures mainly focus on th~ targeted polici~s :formula'tionandall)()On~lf~'lna.ndhigh-efficient technologies development.The differences arid similarities in energy Cop~ervationand emissilJ,nreduc~ionin found~ indust~ between China and other countries were discussed, while, the future development trendwasalso pointed out.

Key words: energy conservation; emission reduction; found~CLC number: TG2-1/X70 Document code:A Article 10: 1672-6421(2010)04-392-08

With the world-renowned United Nations ClimateChange Conference opened in Copenhagen, Denmark,

a magnificent prelude to low-carbon economy has been started.Many countries announced their targets on carbon emissionreduction, and Chinese government promised too to reduce 40%-45% by 2020 per unit GDP compared with the data in 2005 II].Low-carbon economy practices the sustainable development

characteristic of low energy consumption, low emission andlow pollution. However, it is inevitable to experience the stageof high energy consumption and high pollutants emissionfor the growing developing countries. This is decided by the

Male, born in 1958, is currently the President and doctoralsupervisor of South China University of Technology. He isalso the Director of National Engineering Research Centerof Near-net-shape Forming for Metallic Materials. DuringFeb. to May of 1997, he had been to the Institute of'MetalPhysical,TechnicalUniversityof Bertinas a guest professor forcooperating research. His research interest mainlyfocuses onthe preparation and formingof metallicmaterials, and by nowhis academic study has led to the publicationof 182 papers,of which44 are cited by SCI and 60 by EI. So far he holds 10inventionpatents inChina.E-mail:mehjli@scut.edu.cnReceived: 2010-07-21; Accepted: 2010-09-20

industrial structures of individual country. For example, thefast economic development in China is brought about by theSecondary Industry with high energy consumption and highpollution. The green-house gas emission in China is rankedsecond in the world. In fact, China devote much attention toenergy-saving and emission-reduction, and from 1990 to 2005,the actual greenhouse gas emission in China has been reducedabout 46%. According to the statistics up to the first half of2009, unit GOP energy consumption in China had fallen by13 percent accumulatively from 2005, and it was expectedto drop 5 percent in 2009 and realize the overall objective ofdeclining 20 percent by the end of 2010 [2]. It means that theCO2 emission reduction during 2006-2010 in China would goup to over 1.5 billion ton.China can hardly satisfies the economic demand to carry

out such high-end carbon-reduction technology like USA, forthe huge investment; neither can China realizes "low-carbon"by means of trimming the production scale. However, theemission reduction could be realized through energy saving.For the special conditions in China, technologically, thereare two ways for low-carbon economy devc~lopment, one fordirect CO2 emission reduction by energy saving and energyefficiency; and the other for indirect CO2 emission reductionby adopting modern technology and equipment with lowemission.

November 2010The 69th WFC Paper ••I --'

• Coal• Crude oilD Natural gasc Hydropower, nuclearpower, wind power

~3000Q)<J

~ 2500o'5. 2000E~ 1500o~ 1000

~ 500 ....w

o~~~gm~~~~~~~~8o~~~~~bm~mmmmmmmm~mmoooooooo_~ NNNNNNNN

Year

Fig. 2: The increase of energy consumption andenergy structure in China (1978-2007)[5]

(2) Heat treatment and shell roasting: including the heattreatment of casting steel, iron, aluminum and copper alloy.The energy consumed is mainly in the form of electricity, fueloil and gas.(3) Mould and core-making: the energy consumed is mainly

in the form of electricity, fuel oil and gas.Figure 2 illustrates the changing trend of energy consumption

and energy structure in China from 1978-2007151, where theenergy consumption in Chinese foundry industry is about 25%-30% of the total energy consumption in machinery industry,with the average energy utilization of 17%. By the year of2002, energy consumption in China occupied the second placein the world, keeping an increasing rate of 8.9% since the tumof century. Energy consumption in Chinese foundry industryis about two times of those in developed countries. Accordingto statistics, materials and energy inputs in casting productionof China accounted for about 55%-70% of the output. Grossweight of Chinese castings is about 10%-20% higher than thatof the foreign one, and the average process yield of casting steelis 55% while the foreign data is about 70%. In China, one tonof qualified cast iron needs to consume 830 kg standard coal inaverage, accounting for production costs of 15%, while the datain Japan is only the costs of 4.3%.

1 Analysis on energy consumptionsituation and energy-savingpotential in casting production

Foundry consumes huge amount of energy, and yield tons ofwastes. Foundry industry is one of major energy-consumptionindustry and exerts significant effect on environment.Especially in China, the energy consumption of steel and ironindustry is very large. The total yield of castings in China is33.5 Mt in 2008, therein, yield of iron castings is 25.2 Mt,steel castings is 4.6 Mt and non-ferrous castings is 3.8 Mt;in 2009, the total tonnage increases to 35.3 Mt, therein, theyield of iron castings is 26.3 Mt, steel castings is 4.8 Mt andnon-ferrous castings is 4.2 Mt. As shown in Fig. 1, statisticsindicated that, the average energy consumption in cast ironproduction in 2007 is 830 kgce/t, whereas it is 334 kgce/t inJapan, 356 kgce/t in Germany, 364 kgce/t in US and 536 kgce/t in UKI31.The value in China is more than two times higherthan those in the developed countries. Though statistics showsin 2009, the volume has dropped to 610 kgce/t in qualifiedcast iron production, it is an important mission for Chinesecasting engineers or scholars to promote energy saving tomake the environmental friendly and realize the sustainabledevelopment in Chinese foundry industry.

Though China has recently become a major foundryproprietor who is on the top of annual yield, it is not a greatpower in foundry. The convincing evidence is that the2009 annual yield in China was 35.3 Mt, which is its tenthconsecutive top ranked annual yield in the world. However itslevel of castings comprehensive quality, materials structure,cost, energy consumption, efficiency and clean-production arefar behind from the global foundry great powers. There aremany problems waiting to be solved by people who are caringof "Made in China".

Fig. 1: Average energy consumption in cast iron productionin five countries in 2007 (*data in 2009)

1.1 Current situation in casting productionThe main casting procedures where energy consumptionarising are as followsl4J:(1) Metal melting: including the melting process of

casting steel, casting iron and nonferrous metal; the adoptedequipment include cupola, all kinds of electric furnaces andcoke ovens. The energy consumed is mainly in the form ofcoal, coke, electricity, fuel oil and gas.

o

610,...-.536....-

334 356 364.....- .....-,...-.

1.2 Resistance and driving force for energyconsumption reduction and efficiencyimprovement

Firstly, CO2 emission reduction has become the key problemin global environmental safety, and countries around theworld have consensus in emission reduction. China has hugepopulation and weak eco-environment. Recently, abnormalclimate events that suspected in associated with globalwarming took place frequently in China, affecting people'sdaily living very much. Therefore, China cannot followthe way of "high-carbon" development while taking thedeveloping opportunities as the biggest developing country.Secondly, energy saving and environmental protection

is the fundamental measures to reduce the raw materialsconsumption, so as to reduced cost and improve competitiveability, and this is in consistent with the interests of enterprises.For this reason, it is one of the basic driving force for energysaving and emission reduction. Moreover, the acceptance ofgreen production by society would bring out huge marketspace, as well as a broad development prospects for companies.

U.K.u.s.Japan GermanyChina*

700co'5. 600Eiil 500c8~ 400i;;2lQ; ~ 300c~Q)

Q) 200Cl

~ 100~

_ Vol.7 No.4

increases.

(I)

(4)R=

where Pi is the production of product i and Wi is weight factorfor product i:Then, the total primary energy consumption can be

decomposed as follows using PPI.

PPILEjLEj=LPi LPi PPI (2)

where Ej is the primary energy consumption of fuel i, IPi,

PPIILPj; LEJPPI represent activity (output), product structureand energy efficiency, respectively, for each e:nduse.Chen et al. (17) proposed a simplified model to evaluate

energy consumption level in typical cast iron production.It is a scientific approach to assess final energy utilizationand consumption level by means of unit finished energyconsumption. Suppose the total feed is M t, and total energyconsumption is N, yield rate is F, the mass of gating systemis MI, reject mass is M2, machined mass is M3, then, the unitfinished energy consumption EF is as follows:

N NIMEF= M-M

I-M

2-M] =F (3)

In case of using the same melting and heat treatmentequipment, the former yield is Fo, and the new one is F, then theincrease rate of yield M =F - Fo, where M"S 1.-Fo' And decreaserate of unit finished energy consumption R is shown as follows:

capital resources. Nagesha studied the energy consumptionsituation in Indian small-scale industry (including small-scalecasting plant), and proposed that the energy efficient firmswere also likely to perform better on the economic front andhence experience higher returns to scale [15J.

Worrell et al. 116J proposed a methodology for analyzing theenergy consumption that uses a physical production index (PPDto account for product structure differences. In calculating PPI,the production of each product and process is weighted by aweighting factor. Generally, the weighting factors are based onthe primary energy used to produce each steel product.

NIM NIM-----Fo FNIM

Fo

Figure 3 indicates the relationship between Rand Fo' Incase of certain ilF volume, R decrease with Fo increasing; andin case of certain Fo volume, R increase with ilF increasing.Namely, the higher the technological level is, the harder the R

1.3.2 Basic energy-saving measurements

There are many factors affecting energy consumption inindustrial production, and many countries take factors such astax or special policy to reduce yields, so as to reduce energyconsumption; however, the reduced yields would transfer todeveloping countries where labor costs is low. Therefore, it doesnot solve the problem of energy saving globally. In addition tomeasurements above, the active approach of energy efficiencyimprovement can achieve the goals also, such as improvingthe energy efficiency of equipment, or deleting directly the

As a developing country, China is facing two majorproblems: one is the more and more acute contradictionbetween economic development and environmental protection,the other is the more and more prominent contradictionbetween supply and demand of resource. Therefore, the Chinesegovernment put forth a series of strategy, including takingresource conservation and environmental protection as a basicnational policy, constructing strategies to build a harmoniousand saving society, developing recycling economy, andestablishing innovative national strategies. To implement theabove objectives, the green development must be taken.However, resistance in energy conservation and energy

efficiency exist. Three major points are listed as followsl61:(1) Economy - Mainly due to the budget increase that rose

from changing or modernizing equipment, and extra costsfrom information processing and analyses for energy-savingtechnology selection.(2) Specific operation difficulties - For example, in general,

the inertia would hinder people's intention to accept change,moreover, the ambiguous future of new technology on energysaving, etc. are of concern also.(3) Organization - For example, the lack of regulatory

organizations that has powers to carry out and supervisepolicies on energy, and so on.

1.3 Analysis on energy-saving potential1.3.1 Analysis model of energy consumption and prediction of

energy-saving potentialEnergy consumption in foundry industry is great, therefore,the energy saving potentiality is huge. Herein, to evaluate theenergy saving potential in casting process, variety of analysismodels were developed by scholars around the world topredict energy conservation potential.British scholars started the analysis study on national

industry energy consumption and energy-saving potential from70 s-80 s of last century 1

71. Phung et al 18J established in 1981

a method to estimate the industry energy-saving potential andcost. Langley analyzed the pattern of energy use in the UnitedKingdom's iron and steel industry [91• Russian scholar Frommeclaimed that by restructuring the production can lead to a 30%reduction in energy demand through case study (101.

More and more scholars focus on energy conservation andgreen manufacturing in the 21st century. Popp concludedthat two-thirds of the change in energy consumption withrespect to a price change is due to simple price-induced factorsubstitution, while the remaining third results from inducedinnovation (II]. Luis et al.112J proposed that increase the input airtemperature of copula could reduce the coke consumption byapproximately 5%. Ozawa et al.(l3J stated that steel productiongrowth drove up primary energy use by 211% between 1970to 1996, while structural changes (production and processmix) decreased primary energy use by 12% and energyefficiency changes drove down energy use by 51%. Kissock etal.[14)proposed that accurate measurement of energy savingsfrom industrial energy efficiency projects can improve futureestimates of expected savings and improve utilization of

November 2010The 69th WFC Paper _I ~

Fig. 4: Contribution rate of each energy-savingmeasurement

-Korea~ --Mexico

, •.•...Brazil--China~India~US

~70. ""I

\

~ 60 \c 50.2IIIIII 40'E'"0 30u

2010

f980 1982 1984 1986 1988 1990 1992 1994 1996 1998Year

Fig. 5: CO2 emission for the steel and iron industry inselected countries (36J

c= [Vi ~i P~l ][ L (i ~)] (5)

where C is total CO2 emissions and E = 'LE/EJE, and CJEj

represent the [mal fuel mix and emission factor (for each fuel),respectively, for CO2 emissions. Applying Eq. (5), recent CO2emission trends for the steel and iron industry in six countries(Korea, Mexico, Brazil, China, India and US) can be drawn, a<;

shown in Fig.5.9080

2.1 CO2 and other pollutants emission andreduction potential in casting production

Kim and Worrel utilizing energy calculation formula [16Jandtaking into account of the emission factors and final fuel mixto construct the equation of CO2emission as follows[351:

At present, the global CO2 emissions that caused bymanufacturing accounts for 43% of total emissions, where theemission from steel and iron industry is 7% of the total!33]andproduces a variety of other waste gases and/or solids includingwaste sand, slag, dust and exhaust. According to statistics, foreach ton of qualified casting production in China 50 kg of dust,100-200 m3of exhaust, and about I ton of waste sand and 0.3 tof waste slag will be discharged [34J.

2 Pollutants emission and reductionpotential in casting production

elimination of heat treatment process; equipment contributionis not as large as expected, just 26%; it is noteworthy thattechnology measurements which has no direct effect on energyconsumption play an important role in energy conservation,where the contribution rates of lost-foam casting and computertechnology are 20% and 17%, respectively, as shown in Fig.4.

40-- F.=50%- F.= 60%

30 ~ F.= 70%-- F.=80%

g20

0::

10

o o 5 10 15 20L\F(%)

Fig. 3: Relationship between yield increase, t:.F and unitenergy consumption reduction, R

high-energy part. It is the direct energy-saving measurements;at the same time, indirect measurements such as by means oftechnological way can be used to improve efficiency.(I) Direct energy-saving measurementsMelting is a key procedure in casting production, and

improving the energy efficiency of melting equipment isthe most direct way to reduce the energy consumption inmelting part11R.19J.Energy consumption in heat treatment ofcasting production in China is great, and efficiency of heattreatment equipment is low. Take ductile iron as an example,traditionally graphitization annealing or normalizing at hightemperature is needed. If qualified as-cast ductile iron canbe produced, heat treatment part could be eliminated or justlow-temperature stress-relief annealing is needed, then, thecontribution to energy saving would be considerable[20-231.(2) Indirect energy-saving measurementsNowadays, the forming technology of castings is developing

in the direction of high-precision, short process, clean and highquality. Advanced casting technology is not only an importantmeasurement in improving casting quality, but it can also be usedin optimizing the entire processl30-32Jso as to improve the near-net-shape level of casting124-271,which could results in the decreaseof rejection rate and increase of process yield and finished rate.Herein, it leads to the improvement of energy efficiency in castingproduction, namely, indirect energy-saving measurements.Chen et al. (l7Jcarried out a case study on the comparison

between direct and indirect energy-saving measurementsin an iron casting plant, where the earlier productionsituation is: large cupola for melting, general sand casting,graphitization annealing for ductile iron, with reject rate of10%, process yield of 70% and finished rate after machiningwas 60%. Its average unit finished energy consumption was583 kgce/t. After modernization, the cupola was replacedby induction furnace, and the sand casting was replaced bylost-foam casting, it succeeded in producing the qualified as-cast ductile iron and therefore eliminated the heat treatmentprocess. The plant utilized computer technology to optimizeproducts design and simulate the production process also.Thus, its current average unit finished energy consumptionhas been dropped to 212 kgce/t already. Chen et al. assessedthe contribution of equipment, forming technology, computertechnology and as-cast ductile iron to energy saving. Resultsindicate that the contribution rate of as-cast ductile iron isthe largest, 37% of energy consumption was cut due to the

Clnm~ ~IDUr~DRV=====-- ._ Vol.7 NO.4

Geilen et aI. [361proposed a new linear programming modelfor the analysis of CO2 emission reduction potentials inJapanes iron and steel industry. The model can be used toanalyze he impact of CO2 taxes on technology selection,iron and steel trade and product demand for the next threedecades. The Japanese iron and steel industry accounts forapproxi ately 15% of the Japanese greenhouse gas emissions.Results btained from the modeling suggested that theseemission will decline from a level of 185 Mt in year 2000to about 150 Mt in years of 2020-2030 because of decliningproducti n and increasing recycling.

2.2 Ma n emission reduction measurementsEmissio is related to energy efficiency and production. Itis effect ve for reducing production yield and increasingequipme t efficiency to reduce emission. However, it doeswork for improving production efficiency to reduce emissionindirectl . Carbon emission is generated in the process ofenergy c nversion from fossil fuel, and coal, oil and naturalgas would eventually be converted into carbon dioxide.Accordi g to data from National Bureau of Statistics )371,per10,000 MB in GDP consumes 45.27 t of standard coal in2009, wile every ton of standard coal consumption leads tothe form tion of 2.49 kg CO2, 0.075 kg of S02' 0.062 kg ofNO, and 0.68 kg of dust. That is to say, if Chinese governmentpromise to reduce 40%-45% of carbon emission per unitGDP by 2020, it has to reduce GDP energy consumption to5.5 t sta dard coal per 10,000 RMB. Herein, carbon emissionreductio is consistent with efficiency increase, and no matterdirect 0 indirect measurements by means of technologyor mana ement to increase efficiency and decrease energyconsump .on, it can playa role in emission reduction.Pollut nts emission in foundry industry mainly consists of

waste ga , sand, slag and dust, which happens during meltingand sand treatment stages and could be reduced by means ofwaste re ycle, application of environmental protection devices,optimizaion of process techniques, and increasing castingsyield rat and quality.It is a positive and effective measure to develop green

casting 0 as to reduce emission of pollutants in castingproducti n [38J.On one hand to adopt advanced technology andequipme t to reduce pollution yield; on the other hand to adoptmature t eatment technology for casting wastes to reduceemission For instance, the applications of energy-saving andenviron ent friendly casting equipment and auxiliary materials,such as moke-suppression and dust-removal equipment forcupola; a plications of sand mould and core adhesive with low-pollution or zero-pollution and with ability of room-temperaturehardenin ; regeneration and recycling, etc.Adva ced technology and management could lead to

emissio reduction indirectly. Especially in developingcountrie like China, most casting plants hardly can affordthe huge investment of environmental-protective equipment.Increase roducts quality can not only decrease the unit finishedenergy c nsumption, but also reduce emission indirectly. Majortechnolo y and policy measures are as follows:

(1) Near-net-shape casting technologyWith high-precision, short-process, clean :and high-quality,

near-net-shape forming technology is not only able to promotecasting quality, but also increase yield rate, decrease reject rateand increase casting precision. For example., using lost-foamcasting, GM of United States manufactured Ecotec Series2.2L-I4 aluminum cylinder with a weight of only 25 kg, whichis 6.7 kg lighter than that produced by sand casting. Assumingan annual output of 4 million pieces, reduction of 0.7 kt wasteslag, 3 kt waste sand and 24,000 km3 waste gases would berealized annually.(2) Computer simulation technologyDesign and pilot production cycle calll be cut short if

computer technology was applied. Computer simulation canpredict shrinkage cavities and porosities; it can help in theoptimizations that guide the production, decrease reject rateand increase casting quality. The optimization in the design ofgating system could increase materials utilization, decrease theproportion of gating and riser part. Therefore, the above effectcan reduce mission indirectly.(3) Management and policy measurementsManagement measurements include production management,

logistics management, equipment management and personnelmanagement and training. In addition, policies related toemissionI36.39J,such as emission tax and corresponding industryaccess system, is effective also.

3 Situation and strategy of energysaving and emission reductionaround world

3.1 Policies on energy saving andl emissionreduction around the world

As the energy-saving motivation has be,en shifted fromenergy security to environmental protection, it requires theintervention from government and legal policy. In order toensure the realization of energy saving, western countries havedeveloped laws corresponding to energy saving and emissionreduction 140.411.Environmental legislation started early inUS, and in 1970, "National Environmental Policy Act" waspromulgated 142J.In Germany "Waste Disposal Law" waspromulgated in 1972 [431.In Japan "Energy Saving Law" wasestablished in 19791401.The implementation of above laws andregulations on business and industry played an important rolein energy saving and emission reduction.It is another important initiative to improve energy saving

and emission reduction through tax policies 14-1-461.In Germany,water pollution tax would be levied according to the effluentemissions and waste-water quality; in Sweden, air pollutiontax started to impose on sulfur dioxide emission since 1991;France government encourages to adopt energy-saving devicesby means of tax relief; in Japan, business and industries usinglisted energy-saving devices could get tax relief, the relievingproportion is 7% of the cost of the purchased equipment 147J.There are government agencies in Europe lmd United States

November 2010

that devoted in energy conservation with different institutionalarrangement and functions. There is Energy Efficiency andRenewable Energy Agency (EERE) in U.S. Department ofEn~rgy. German Energy Agency, established in 2002, is incharge of public consultation provision of energy savingand emission reduction, whose study results indicate thatstrengthening management of enterprise could lead to a 15%-20% reduction in energy consumption 1

481.

In general, regardless of the implementation of mandatory orguiding policies, the foothold for promoting energy conservationand emission reduction is on the use of market mechanism indeveloped countries, such as Europe, U.S. and Japan.

3.2 Situation and strategy of energy savingand emission reduction in China

In 2008, "Energy Conservation Law" and "Water PollutionControl Act" got amended, and "The State Council's decisionon strengthening energy conservation" was released, whichmeans that Chinese government has taken energy andresource conservation as a basic national policy, plus takingthe completion of conservation goal as one of the evaluationstandards on local governments and their leaders [49

1•

Bureau of Energy, National Development and ReformCommission stated that China would continue to implementthe financial and tax polices to encourage the technologicalinnovation in enterprises, enhance the degree of absorption,acceptance and re-innovation of energy technology, andaccelerate the industrialization and application of high-techenergy. Meanwhile, China goes on establishing and amendingrelated policies and regulations to resource and energyeffective utilization, developing the strict access standard forhigh-consumption and high-pollution industries, acceleratingthe standard constitution of mandatory energy efficiencyfor products, revising and improving energy-saving designstandards in major energy-consumption industries, establishingbuilding energy efficiency standard at an accelerating pacel50I

•

At present, China is considering to introduce green taxes, topromote"green" transformation in current tax system 1

511. China

has reformed resources tax, gradually increasing tax rate andregulating tax standard of coal, crude oil, manganese ore andso on. China is going to start the access systems to eliminatebackward technology and business, and improve business scaleand level.

Aimed at accomplishing "Energy Conservation and EmissionReduction Implementation Program", Ministry of Scienceand Technology, the National Development and ReformCommission, the Central Propaganda Department, ChinaAssociation for Environmental and Resources Protection,NPC, and Population, Resources and Environmental ProtectionCommittee, CPPCC, together issued "National Scienceand Technology Action Plan on Energy Conservation andEmission Reduction", and proposed to construct four energy-saving integrated demonstration projects, which focus onbusiness science and technology demonstration. Namely,to carry out business model focus on increasing energyefficiency and reducing waste emission, including eco-design

The 69th WFC Paper • iiiii.iiii'i11

of products, modifications of high-energy and high-pollutiontechniques and equipment, and clean production demonstrationin local key industries 1521. In 2008, Guangdong Province,China, started the major science and technology specificprojects, including "Integrated Technology Application andDemonstration on Energy-saving.and Emission-reduction inFoundry Industry", which can realize zero discharge of wastesand, plus total annual increase revenue up to 5.2 millionRMB. If implementing the project in plants, it can reduce9.45 million cubic meters of gas emission, saving 75,000 t ofstandard coal per year, thus, reducing 150 t of sulfur dioxideemission indirectly.

3.3 Developing trend of energy conservationand emission reduction in China

Chinese foundry industry is far behind from developedcountries, it usually accompanied with high energyconsumption and serious pollution, however, it left large spacefor enterprises innovation. Global financial crisis in 2008exerted great impact on Chinese foundry industry, and forcedit to adjust the industry structure so as to fit into the sustainableeconomy. Its energy-saving and emission-reduction shouldfocus mainly on quality promotion, rejection decrease andwaste reduction, by means of near-net shaping, computer

. technology, new materials technology, advanced melting,forming techniques and equipment, smoke, dust and slagcontrol and materials recycling. It should be the integrationand innovation with modern management, advancedtechnology and equipment. The authors believe that energyconservation in foundry industry in China requires continuousefforts and improvements, including: (l) legislate new laws,regulations and institutions matching with national policies;(2) Accelerate the structure re-construction and development,and implementation of the access system and relatedstandards in foundry industry; (3) Enhance the applicationof demonstrating technology, strengthen the exchanges andcooperation between enterprises; (4) Increase the investmenton personnel training and technology innovation, improvethe managing and technical level of enterprises; (5) Developresearch on materials recycling and reuse, especially on thewaste metal classification and management. It is also importantto develop new techniques in waste metal reuse directly as rawmaterials and integrating the metal regeneration with materialspreparation and forming.

4 ConclusionCasting is the basis of manufacturing industry, but it is apolluting industry with big energy consumption. As majorsectors of energy consumption and pollutants (especially CO2),

energy saving issue has rose concerns. Energy conservationand emission reduction is related tightly with the survivaland development of the industry, and it is also a key point ofsustainable development of local economy. Foreign enterprisespay great attention to green casting, and implement positivelyon the 3R principle (Reduce, Reuse and Recycle). Energy

_ Vol.7 NO.4

temperature. Joumal of Materials Processingl Technology, 2002,120(1/3): 281-289.

[13] Ozawa L, Sheinbaum C, Martin N, Worrel N and Price L. Energyuse and CO2 emissions in Mexico's iron and steel industry.Energy, 2002, 27(3): 225-239.

[14] Kissock J K and Eger C. Measuring industrial energy savings.Applied Energy, 2008, 85(5): 347-361.

[15] Nagesha N. Role of energy efficiency in sustainable developmentof small-scale industry clusters: an empirical study. Energy forSustainable Development, 2008, 12(3): 34-39.

[16] Worrel E, Price L, Martin N, Faria J and Schaeffer R. Energyintensity in the iron and steel industry: a comparison of physicaland economic indicators. Energy Policy, 1997,25(7/9): 727-744.

[17] Chen Weiping, Huang Dan, Jiang Fan, Luo IHongfeng. Strategyanalysis on energy conservation and emission reduction infoundry industry. In: 2008 Guangdong Foundry Conference,Guangdong, China, 2008: 65-75.

[18] Prosanto P, Girish S, Abhishek Nand Sanjeev S W. Towardscleaner technologies in small and micro enterprises: a process-based case study of foundry industry in India.. Journal of CleanerProduction, 2008, (16): 1264-1274.

[19] Wijayatunga P D C, Siriwardena K, Fernando W J L S,Shreshtha R M and Attalage R A. Strategies to overcomebarriers for cleaner generation technologies in small developingpower systems: Sri Lanka case study. Energy Conversion andManagement, 2006, 47: 1179-1191.

[20] Xue H a, Bayraktar E and Bathias C. Damage mechanism ofa nodular cast iron under the very high cycle fatigue regime.Journal of Materials Processing Technology, 2008, 202(20):216-223.

[21] Tong X, Zhou H, Ren L a, Zhang Z H, Zhang Wand Cui R D.Effects of graphite shape on thermal fatigue resistance of castiron with biomimetic non-smooth surface. International Journalof Fatigue, 2009,31(4): 668-677 .

[22] Zou Wei, Xu Wanli, Guo Zhipeng, Chen Guoxiang, GengMaoping and Shu Ke. Research on propertie,s of Cu-Mn alloyedas-cast nodular iron and its application. Foundry, 2008, 57(6):615-618.

[23] Gonzaga R A and Carrasquilla J F. InfluenC4~of an appropriatebalance of the alloying elements on microstructure and onmechanical properties of nodular cast iron .• 'ournal of MaterialsProcessing Technology, 2005, 162-163: 293.-297.

[24] Askeland D R. Lost Foam Casting (Disposable Mold).Encyclopedia of Materials: Science and Technology, 2008:4641-4644.

[25] Caulk D A. A foam melting model for lost foam casting ofaluminum. International Journal of Heat and Mass Transfer,2006: 49(13-14): 2124-2136.

[26] Huang Naiyu, Ye Sheng ping and Fan Zitian .. Lost-foam castingtheory and quality control. Wuhan: Huazhong University ofScience and Technology Press, 2004. (in Chinese)

[27] Ye Sheng ping and Sun Zhicheng. Application of aluminum lostfoam castings in America and suggestions for promoting lFC ofaluminum alloys in China. Foundry, 2008, 57(3): 203-207. (inChinese)

[28] Voorhis T V, Peters F and Johnson D. DevEtloping software forgenerating pouring schedules for steel foundries. Computers &Industrial Engineering, 2001, (39): 219-234.

[29] Zhou J X, Chen l l, Liao D M and Liu R X. High pressurediecasting module of InteCAST software and its applications.Joumal of Materials Processing Technology, 2007, 192-193:249-254.

[30] Shehata F and Abd-Elhamid M. Computer aided foundry die-design. Materials & Design, 2003,24(8): 577-583.

[31] Uu B C. Modeling and simulation's role in equipmentmanufacturing and prospects. Aeronautical Manufacturing

ncas

conserv ion should be based on the application of advancedtechnolo y to improve casting quality, instead of decreasingconsum tion and emission simply.Energ conservation in foundry industry can be divided

into two ways: one is the dominant and direct energy-saving,through equipment improvements (to improve efficiency);the othe is the indirect energy-saving, namely, to decreasethe ene y consumption per unit mass of product throughimprov ng technology level. Recessive energy-savingmeasure not only contribute greatly to energy consumptiondecrease but also improve product quality.Redu tion of pollutants and waste emission in foundry

industry can be classified into two categories also: one is toreduce t e yield of wastes and pollutants through advancedtechnolo y and device; the other is to reduce emission throughnew tee nology to treat and recycle wastes.There ore, the energy conservation and emission reduction

in found industry should take casting quality and technologyimprove ents as core mission, integrating multiple advancedtechniq es and equipment, such as advanced melting andforming, computer technology, smoke, dust and slag treatmenttechnolo y and so on, to constitute composite clean techniquefor casti g production and reduce producing cost, so as torealize onservation of energy and reduction of emissionduring asting production, and establishing foundation forsustaina Ie development of foundry industry.

[1] D and Ban Ki-moon. Praised China's emission reductionco mitment and was optimistic about Copenhagenpro peets [EB/OL].http://www.cnr.cn/allnews/200912/1200 1211_505745154.html. 2009-12-11.

[2] We J B. Government Work Report. [EB/Ol]. http://news.xinh anet.com/newscenter/2008-03/19/content _7819983.htm.200 3-29.

[3] Hua g Tianyou, Fan ai, Zhang Libo, et al. Study on the Policiesof E ergy Saving and Emission Reducing of Chinese FoundryInd stry. Foundry Technology, 2009, 30(3): 399-404. (inChin se)

[4] Zha g Boming. Energy consumption in foundry production.Mod rn Cast Iron, 2006 (5): 13-17.

[5] Wan Q and Chen Y. Energy saving and emission reductionrevo utionizing China's environmental protection. Renewableand ustainable Energy Reviews, 2010, 14: 535-53.

[6] Roh in P, Thollander P and Solding P. Barriers to and drivers forene y efficiency in the Swedish foundry industry. Energy Policy,200 ,35(1): 672-677.

[7] Chri topher W L. The potential for energy conservation in UKindu try. Energy, 1979,4(6): 1175-1184.

[8] Doan l P and Willem V G. Assessing industrial energycon ervation by unit processes. Energy, 1981,6(5): 419-440.

[9] Lan ley K F. Energy efficiency in the UK iron and steel industry.Appl ed Energy, 1986,23(2): 73-107.

[10] Fro e J W. Energy conservation in the Russian manufacturingindu try - Potentials and obstacles. Energy Policy, 1996, 24(3):245 252.

[11] Pop DC. The effect of new technology on energy consumption.Res urce and Energy Economics, 2001, 23(3): 215-239.

[12] luis C J, Alvarez l, Ugalde MJ and Puertas I. A technicalnot cupola efficiency improvement by increasing air blast

November 2010

Technology, 2008, (3): 26-30.[32] Shehata FA. Computer-aided foundry cupola and mold analysis.

Journal of Materials Processing Technology, 1997,63(1-3):

655-660.[33] Price L, Worrell E and Phylipsen D. Energy use and

carbon dioxide emissions in energy-intensive industriesin key developing countries. In: 1999 Earth TechnologiesForum,Washington DC, USA, 1999.

[34] Jia C B. Speech on Fourth Council of Fifth China FoundryAssociation Conference (Summary). Foundry Panorama, 2009,

9: 1-4[35] Kim Y and Worrel E. Intemational comparison of CO2 emission

trends in the iron and steel industry. Energy Policy, 2002, 30:

927-929.[36] Geilen D and Moriguchi Y. CO2 in the iron and steel industry:

an analysis of Japanese emission reduction potentials. EnergyPolicy, 2002, 30(10): 849-863.

[37] National Bureau of Statistics. China Statistical Yearbook -2006.http://www.stats.gov.cn/tjsj/ndsj/2006/indexch.htm. 2006.

[38] Shang J L, Chen W P, Zhu Q L, Li Y Y. Thoughts on SustainableDevelopment of Foundry Industry in China. Materials Review,

2007,21(5): 1-7.[39] Oda J. Akimoto K., Sano F. and Tomoda T. Diffusion of energy

efficient technologies and CO2 emission reductions in iron andsteel sector. Energy Economics, 2007, 29(4): 868-888.

[40] Hanaoka H, Yoshida Y, Matsuhashi Rand Ishitani H. Potentialreduction of fluorocarbon emissions under the enforcement ofnew laws in Japan. In: Greenhouse Gas Control Technologies-6th Intemational Conference, Kyoto, Japan, 2002: 1257.

[41] Moussiopoulos N, Vlachokostas C, Tsilingiridis G, et al. Air qualitystatus in Greater Thessaloniki Area and the emission reductionsneeded for attaining the EU air quality legislation. Science of theTotal Enviomment, 2009, 407(1): 1268-1285.

The 69th WFC Paper

[42] Yin Z J. History of the United States environmental laws[Dissertation]. China University of Political Science, Beijing,2005.

[43] Storm P C. Environmental Laws [EB/OL]. http://www.iuscomp.org/glalliterature/envirmt.htm. 2000.7.

[44] Clinch J, Dunne L and Dresner S. Environmental and widerimplications of political impediments to environmental tax reform.Energy Policy, 2006, 34(8): 960-970.

[45] Agnolucci P. The effect of the German and British environmentaltaxation reforms: A simple assessment. Energy Policy, 2009,37(8): 3043-3051.

[46] Ekins P. European environmental taxes and charges: recentexperience, issues and trends. Ecological Economics, 1999,31(1): 39-62.

(47) Energy Management [EB/OL). http://www.energy managertraining.com/new _Learning-ENERGYMANAGEM ENT.php [49]2010.1.

(48) Introduction to -Germany Energy Agency [EB/OL). http://www.dena.de/en/. 2010.1.

(49) Chen F. "Energy Conservation Law" and a number of laws andregulations, shall come into force from April 1, 2008 [EB/OL].http://www.gov.cnlflfg/2008-03/31/content_927869.htm. 2008-3-

31.[50) Development and Reform Commission is going to increase

energy conservation efforts [EB/OL]. http://www.jnjp.com.cn/info/. 2009-3-6.

[51) Ministry of Environmental Protection: China is currently studyingthe introduction of green taxes [EB/OL]. www.cnmn.com.cn/ShowNews.aspx?id=13848. 2009-3-27.

[52) Implement energy conservation program and start demonstrationproject [EB/OL]. http://www.21-sun.com/china/2005/219hyxw/hyxwdetail.asp?findid=30333. 2009-11.

This work is financially supported by Guangdong Major Science and Technology Specific Project, grant number2008A080800022. The paper was presented at the 69th WFC, Hangzhou China 2010, republished in ChinaFoundry with the author's kind permission.