Thesis Amajit

8/2/2019 Thesis Amajit

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Development of Computer Aided Heat Treatment

Planning System for Quenching & Tempering(CHT-q/t)

and Industrial Application

of CHT-bfand CHT-cfM.S Thesis Defense presentation

By

Amarjit Kumar Singh

Advisor: Prof. Yiming (Kevin) Rong

Prof. Diran Apelian Thesis Committee

Prof. R .D. Sisson. Jr, Thesis Committee

Prof. M. A. Demetriou, Graduate Committee


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Outline

Introduction to Heat treatment process

Industrial need of a simulation software

System design of CHT- q/t Database design

Enmeshment of Box shape workpiece

Mechanical properties prediction after quenching

Case study with CHT- q/t Industrial application of CHT- bfand CHT- cf

Summary


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Introduction to heat treatment

Heat Treatment may be defined as heating and cooling operations applied tometals and alloys in solid state so as to obtain the desired properties.

The main types of heat treatment applied in practice are

Annealing

Normalization

Hardening and

Tempering

Some of the objectives of heat treatment are summarized as follows:

Improvement in ductility

Relieving internal stresses

Refinement of grain size Increasing hardness or tensile strength

Improvement in machinability

Improvement in toughness


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Industrial need of a heat treating software

Furnaces are widely used for the heat treatment of mass production parts.So to optimize the heat treating process is of great significance.

The present simulation softwares, unable to integrate the part load and

furnace model with the heat treating process.

Foundation of CHT- q/t

CHT-bfand CHT-cfas the foundation of CHT- q/tfor several database andheating module

QuenchPAD for the quenchant database.

Challenges for development of CHT- q/t

CHT-q/tneeds a complete database, most function modules are databaseoriented.


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Definition of CHT- q/t

CHT-q/tis a software tool to predict the temperature profile of load in

batch as well as continuous furnace during heating, quenching and

tempering of steel, then to predict the mechanical properties as Quenched

& Tempered and finally to optimize the heat treatment process design.

Part information

Quenchantinformation

Temperature vs timeof all parts

Properties in load

Fuel flow rate-time

profile

Heat-time profileof each part

Heat transfercalculation

Load pattern

Input

Output

Furnace information

Dynamic cooling result

Phase

transformation

Property prediction

Database

Workpiece Material

Furnace

AtmosphereFuel

Workpiece geo.


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Function flow chart

Describes the functionmodules, database and

output of CHT- q/t

Module 2Heating

Module 5Tempering

Heating below austenizing temperature

Output 3Mechanical Properties

after Quenching

Output 5

Mechanical Propertiesafter Tempering

DB1Material & TTT profile DB

Output 1Heat term &

temperatures

Module 4Phase transformation prediction

(Austenite to pearlite / bainite / martensite)Comparing cooling curve with TTT diagram to

determine microstructure

Mapping of microstructure to properties

DB4Quenchant DB

Module 1Workpiece classification & enmeshment

Workpiece shape classificationEnmeshment by Biot no.

Output 2Cooling curve of eachworkpiece and inside

the workpiece

Output 4Heat term &temperatures

Module 6Property prediction by empirical equations

DB2Furnace DB

Heat transfer for gas quenching in same furnaceused in heating

Heat transfer for oil quenching in tank(load with fixture, single workpiece without fixture)

Heat transfer for gas quenching in differentfurnace

Initial condition

Cooling

Workpiece Furnace Load pattern Thermal schedule

Module 3

DB3

Atmosphere DB

DB6

Tempering propertiesDB

DB5Quenching properties

DB


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Database design

CHT-q/tneeds extensive database to increase its applicability, as most of themodules strongly depend on database.

The TTT and quenchant database are the new addition.

Material and properties It comprises of workpiece as well as furnace materials.

Considers non-linearity of properties

Addition of TTT diagrams for steels

Workpiece shape 13 basic shapes

Furnace Batch & Continuous furnace for heating

Dual chamber furnace, vacuum furnace, quenchant tank for cooling

Atmosphere Fuels

Quenchants Frequently used gas as well as liquid quenchants


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TTT database development

In CHT-q/tsteels are classified as

Carbon steel

Alloy steel

Tool steel

Stainless steel

Steps for the conversion of the TTT diagrams in

tabular format Convert in digital format

Pick the start and finish curves at temperature duration of 20 deg

The value range from Austenitic start to martensitic start

Store Ms and Mfvalues as well

Source: TTT diagrams taken from Atlas of Time-Temperature Diagrams forIrons and Steels

http://nick-gd.chat.ru/index2.htm

0

200

400

600

800

1000

1200

1400

1600

1 10 100 1000 10000 100000


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TTT Database as shown in CHT- q/t

TTT Database as shown in CHT- q/t

User has the option to add or edit the TTT database as well


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Quenchant database development for gas quenchant

Relationship between gas pressure and the heat

transfer coefficient at 500 degree C and 15m/s

Reference:Torsten holm, Soren

segerberg, Gasquenching

branches out,

advanced materials

and processes, 1996.


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Quenchant database development for liquid quenchant

H

eattransfercoefficient,W/m2K

0

1000

2000

3000

4000

5000

6000

0 200 400 600 800

Convection stage

Boiling

sage

Vapor

blanket

stage

TA-B TB-C

Temperature,

Boiling

stage

TA-BTB-C

The quenchant database considers the variation of convective heat transfer coefficient in

all the three stages i.e. film boiling, bubble boiling and convection stages during liquid

quenching


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Classification of workpiece

3-step

shaft

2-step

shaft

coneBase

Hollow

cone

Hollow

cylinder

2-stacked

brick

TorusSphereConeCylinderBox

Shapes

Class VClass IVClass IIIClass IIClass IClass

Class I

The enmeshment was one dimensional for CHT- bfand CHT- cfThe desired output of the hardness value at all the internal locations of part led

to the development of 3-dimensional enmeshment.


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3-Dimensional enmeshment

Classification of workpiece by Biot number

Case 1: Lumped heat capacity model

Case 2: Exact model

Lumped heat capacity modelInput Conditions:

The dimensions of the box (D1, D2, & D3).

The initial temperatures of the part.

Temperature of the quenchant gas.

Where, Ta is the ambient temperature

Ti is the initial temperature of part

F0 (Fourier number) is and

Thus we can get the final temperature T, by using the above equations

[ ]0exp FBTT

TTi

ai

a=

20

.

cL

tF

=

pC

k

=

1.iB

1.>iB

Conductivity and specific heat as a function of temperature


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Bi > .1, exact solution to be used

Input:

Dimensions of the box (D1, D2, & D3).

Specify the origin as shown in the figure.

Input the values n, l ,m

The initial temperatures of the part.

The time step

Ambient or quenchant temperature.n

Dx 1=

l

Dy 2=

m

Dz 3=

Internal nodes

i j k1 (1 to L-1) (1 to m-1)2 (1 to L-1) (1 to m-1)

(n-1) (1 to L-1) (1 to m-1)

Boundary nodes

i j k0 (1 to L-1) 0, m1 (0 to L) 0, m n-1 (0 to L) 0, mn (1 to L-1) 0, m

i j k0, n (1 to L-1) 00, n (0 to L) 1

0,n (0 to L) m-10, n (0 to L-1) m

i j k0, n (1 to L-1) 00, n (0 to L) 1

0,n (0 to L) m-10, n (0 to L-1) m

Corner nodes: (0, 0, 0) (n, 0, 0) (0, L, 0) (n, L, 0) (0, 0, m) (n, 0, m) (0, L, m) (n, L, m)


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Microstructure evolution and property prediction

Properties to be determined

Hardness

Ultimate Tensile Strength

Yield Strength

Approach: Analytical approach for asquenched. Hardness value for allthe nodes to get hardness

distribution.

For other properties equations used,as a function of hardness. Theaverage value of hardness used todetermine other properties.

Database approach for as tempered.

Module 2Heating

Module 5Tempering

Heating below austenizing temperature


after Quenching


after Tempering

DB1

Material & TTT profile DB

Output 1Heat term &

temperatures

Module 4Phase transformation prediction

(Austenite to pearlite / bainite / martensite)Comparing cooling curve with TTT diagram to

determine microstructure

Mapping of microstructure to properties

DB4Quenchant DB

Module 1Workpiece classification & enmeshment

Workpiece shape classificationEnmeshment by Biot no.

Output 2Cooling curve of eachworkpiece and inside

the workpiece

Output 4Heat term &temperatures

Module 6Property prediction by empirical equations

DB2

Furnace DB

Heat transfer for gas quenching in same furnace

used in heating

Heat transfer for oil quenching in tank(load with fixture, single workpiece without fixture)

Heat transfer for gas quenching in differentfurnace

Initial condition

Cooling

Workpiece Furnace Load pattern Thermal schedule

Module 3

DB3Atmosphere DB

DB6

Tempering propertiesDB

DB5Quenching properties

DB


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Hardness

Microstructure after quenching

( )

( ) ( )[ ]TtTtww

nfs

fs

/log

1ln/1lnlog =

The kinetics of the growth of ferrite and pearlite are described using the

Avrami-Johnson-Mehl equation

where,

w : volume fraction of austenite transformed

b,n : coefficient and exponent of the austenite transformation kinetics,

t : timets : start timetf : finish time

= 0.01

= 0.99

( )( )Tt

wb

s

s=

1ln

sw

fw

( )nsttbw = .exp1

( ) ( )( )( )TMwww sBPM = .011.exp1*1

Reference: V. C. Prantil, M. L. Callabresi and J. F. Lathrop, SimulatingDistortion and Residual Stresses in Carburized Thin Strips, vol. 125, April 2003


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Hardness Calculation

A continuous cooling curve is

divided into constant temperature

steps with appropriate times . It is

assumed that the horizontal partsof this step function cause a

transformation comparable to the

transformation occurring at the

individual temperatures in theisothermal TTT-diagram. By an

iteration of the transformation

steps the final microstructure is

derived.

Tempera

tureT

Time t Time log t

step function

real courseof cooling

M

B

P

A

HV

HV

HV


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Regression Analysis

Hardness=f(C%, Martensite%)

The equations of the form:

H= ax2 +bx+c,x--- C%

The equation at 50% Martensite

y = -19.0476 x^2 + 64x + 20.1448

The equation at 80% Martensitey = 7.14286 x^2 + 50.6429x + 25.6529

Similarly, generating the HRC value for all the martensitic percentage points

Reference:http://people.hofstra.edu/faculty/Stefan_Waner/RealWorld/newgraph/regressi

onframes.html


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Ultimate tensile strengthUTS=a*HB+b

Brinell hardness is used

Aim is to find constants a and b.

Value of constants for stainless steel

Validation for low alloy steel (5140) having hardness of 167 HB.

UTS calculated by the mentioned equation comes to be 572.278 MpaAnd the UTS of a specimen having hardness 167 HB should be 573 Mpa

Reference: Mechanical properties of Work Materials, Edmund Isakov

Validation source:http://www.efunda.com/materials/alloys/alloy_home/steels.cfm

U.T.S = 508 HB - 3900(156-595) HBAISI 400-seriesMartensitic

U.T.S = 430 HB + 6530(140-190) HBAISI 400-seriesFerritic

U.T.S = 534 HB - 16280(190-370) HBAISI 300-seriesAustenitic

U.T.S = 457 HB + 16910(140-180) HBAISI 300-seriesAustenitic

U.T.S = 606 HB - 31600(250-400) HBAISI Type 201Austenitic

Ultimate tensile strengthHardness RangeDesignation and GradeClass


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Hardness Conversion tablesConversion of HRC to HB

HB = 17.602 HRC - 403.86661

HB = 19.038 HRC - 489.46056

HB = 15.962 HRC - 318.75551

HB = 12.473 HRC - 142.65046

HB = 10.025 HRC - 30.84541

HB = 8.872 HRC + 16.04036HB = 8.379 HRC + 33.73531

HB = 6.984 HRC + 76.13026

HB = 5.329 HRC + 119.62520

tofrom

to Brinell Hardness (HB)

Numbers

(HRC)

Equations to convert Rockwell hardness

(HRC)

Rockwell

Hardness

Conversion of HV to HB

HB = 0.940 HV - 0.2670500

HB = 0.909 HV + 15.1499400

HB = 0.944 HV +1.2399300

HB = 0.922 HV + 7.3299250

HB = 0.954 HV - 0.7249200

HB = 0.949 HV + 0.9199150

HB = 0.959 HV - 0.814985

tofrom

into Brinell Hardness (HB)Number (HV)

Equations to convert Vickers

hardness (HV)

Vickers

Hardness

Reference: Mechanical properties of Work Materials, Edmund Isakov


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Calculation of Yield Strength

The materials are classified into three categories, plain carbon, low alloy and

alloy steel.

For plain carbon steel kis between 0.6 to 0.65, for low alloy steel kis 0.65 to

0.75, and alloy steel kis 0.84 to 0.86.

The value of k has been further refined and added in the database for each

grade of steel.

k = Yield strength / U.T.S

bs k =

Reference:

http://www.efunda.com/materials/alloys/alloy_home/steels.cfm


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Implementation

Case Study 1 at American Heat Treating, CT

Material: Alloy Steel 4340Weight: 0.3 lbsFurnace: VFS Vacuum Furnace

Load : 5 baskets arranged load


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Quench Gas Atmosphere Nitrogen

Quench Pressure 2 bar

Blower HP 160

40200Nitrogen (2bar)

Quenching

501950VacuumSoaking

1201750VacuumSoaking


From room

temp.

70-1000VacuumHeating

Time (mins)Temperature

(F)

Atmosphere

Content

Process


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Comparison of calculated and measured results

0

500

1000

1500

2000

2500

0 100 200 300 400 500

TC1(top)

TC2

TC3TC4

TC5

TC6

TC7

TC8

TC9

TC10

TC11

TC12(BOT)

CALC_S

CALC_F



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Case Study 2 at Bodycote, Worcester, MA

Workpiece Stainless steelQuench Gas Atmosphere Nitrogen

Quench Pressure 2 bar

Blower HP 200

Furnace Abar Vacuum Furace


from roomtemp.

70-1900VacuumHeating

200200Nitrogen (2 bar)Quenching

Time (mins)Temperature

(F)

Atmosphere

Content

Process


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Case Study 2 at Bodycote, Worcester, MA Measured & Calculated results

0

500

1000

1500

2000

2500

0 100 200 300 400 500 600

Time (mins)

Temperature(F)

Meas. slow

Meas. fast

Calc. furnace

Set Point

Calc. fast

Calc. fast


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Case Study 2 at Bodycote, Worcester, MA

Dynamic cooling results


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Summary and future work

Discusses the function and domain of CHT- q/t

CHT- q/tdesigned to meet industrial need, close contact with industrieskept to review their needs and implement the idea.

The basic advantages lies in short computation time, easy to use and the

ability to integrate the part load and furnace model with the complete heattreatment process.

Database development (especially TTT and quenchant database)

Development and validation of property prediction module

Validation of the new interface as well as cooling module in industry.

Future work More case studies required to validate the system

Enhance database for TTT diagram and quenchant Analytical approach to find convective heat transfer coefficient

Analytical approach to find properties after tempering


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Industrial Applications of CHT- bf

Case studies performed at Bodycote ThermalProcessing, Worcester

Objective To study the effects of change in the load quantity and giving

recommendations for the thermal schedule redesign.

To study the effect of change in load arrangement and determination ofoptimal load pattern from the calculated temperature values.

To determine the pre-heat required to reach the set point temperature andhence to determine cycle time.

Scheduling of jobs in furnace after determining exact cycle time.

To study the effect of part orientation on the quality and distortion andhence to determine best suited load orientation.


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Pit Furnace

Alloy, 1000lbsOthers

Alloy, 100lbsSupports

Graphite, 50lbsHeating

elements

Furnace Accessories data

(weight and material)

0Rate of

cooling water

35Weight

1140 R.P.MSpeed

4.5Height

14Diameter

2Horse power

303Material

[ x] Yes [ ] NoRecirculation Fan

(one fan at top)

[ ] Yes [ x ] NoVacuum Furnace

NoExcess of preheated air (%)

No preheatAir preheated temperature

AirAtmosphere content

120 kw or 409416.58 BTU/hrConnected heat input

1000Minimum Operating Temperature

2500 FMaximum Operating Temperature

45 x 60Work space (LengthWidth Height) or

(diameter Height)

5 x 8External size(LengthWidth Height) or

(diameter Height)

ElectricHeating type(E.g. direct/indirect fired, electric)

VerticalBody Shape

(E.g. vertical, Horizontal)

Pit furnace, 416Furnace name


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Case study 1 at Pit furnace

Workpiece Information

2Work piece weight

1137Work piece Material

R. H. HandlesWork piece Name


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Load Pattern

362Total weight of workpiece in fixture, lbs

181Total quantity of workpiece in fixture

ArrangedLoad pattern, Fixture configuration

35, 25Fixture size (diameter , height) inch

300 lbsFixture weight

SolidSide wall, bottom (solid/net like)RoundFixture shape (rectangular/round)

BasketFixture type (basket/plate)

Arrangement of load pattern

11

Ring

1019Ring 5

14Ring 920Ring 4

16Ring 821Ring 3

17Ring 722Ring 2

18Ring 623Ring (Row)1

QuantityRowQuantityRow

Quantity in each ring


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Comparison of result (soaking time: 305 min)

Temperature-Time chart

0

200

400

600

800

10001200

1400

1600

1800

0 100 200 300 400

Time (min)

Temp(F) Part (slow)

Part (fast)

Furnace

Conclusion: Part Temperature remains almost constant after 180 mins. The

optimum cycle time prior to heat treating can be determined.


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Comparison of result (Reduced soaking time:

180 min)

Temperature-Time chart

0

200

400

600

800

1000

1200

1400

1600

1800

0 50 100 150 200

Time (min)

Temp(F) Part (slow)

Part (fast)

furnace


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Case study 2

Two types of part(same material)

present in the load

1. Qty = 300 2. Qty = 903

Wt. = 41 Wt. = 45Thus average workpiece wt =

0.0715

Work piece weight

17-4 stainless steelWork piece Material

Hitchiner part no. 87296 & 87292Work piece Name


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Load pattern

(41 + 45)/2 = 43

Total weight of workpiece in fixture,

lbs

(300 + 903)/2 =


RandomLoad pattern, Fixture configuration

35, 25Fixture size (diameter , height) inch


SolidSide wall, bottom (solid/net like)

RoundFixture shape (rectangular/round)



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Comparison of Result

Actual result

0

500

1000

1500

2000

2500

0 50 100 150 200 250

Time (min)

Temp

(F) Temp (furnace)

Temp (slow)

Temp (fast)

Conclusion: Great opportunity to reduce the cycle time

All 405F


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All case furnace

2 G.P.MRate of cooling

water

200Weight

1800 R.P.MSpeed

14.5 inchesHeight

10 inchesDiameter

5Horse power

330Material

[x ] Yes [ ] No (one fan at top)Recirculation Fan

900Opening area (inch2)

[ ] Yes [ x ] NoVacuum Furnace

15Excess of preheated air (%)

850Air preheated temperature (F)

Endothermic (RX) with enriching gas, dilution

air and ammonia additions

Atmosphere content

1000000, 60000 Btu/hrConnected heat input

Natural gasFuel (combustion air)

1400Minimum Operating

Temperature

1800Maximum Heating

30-48-30Work space (WidthLength

Height) or (diameter

Height)

5.5 4.7 4.8 ftExternal size(LengthWidth

Height) or (diameter Height)

Indirect gas firedHeating type

(E.g. direct/indirect fired,

electric)

HorizontalBody Shape

(E.g. vertical, Horizontal)

All case, 405Furnace name


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Case study on all case furnace (with connected

heat input 600,000 Btu/hr)

0.2312 lbsWork piece weight

8620Work piece Material

Hitchiner 243860Work piece Name


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Load Pattern

140.4 lbs

Total weight of workpiece in fixture,

lbs


1 x 2 x 5

Rows Columns Layers of fixtures

in furnace

RandomLoad pattern, Fixture configuration

29, 23, 4

Fixture size (Length, width, height)

inch


Net likeSide wall, bottom (solid/net like)

RectangularFixture shape (rectangular/round)



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Result

Load takes around 65 minutes to

reach the set point temperature,

although the time allotted to reach

the set point temperature is 30

minutes.

In all case furnace, 10 fixtures are

used for the part load and generally

the parts are randomly placed in thefixture, leaving no room to change

the part load design.


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Result by CHT-bf (same load in furnace with higher

heat input i.e increasing the connected heat input to 1million Btu/hr) The time required by the load to reach

set point temperature reduced from 65

to 40 minutes, as we increased the

connected heat input from 600,000Btu/hr to 1000000 Btu/hr, thus saving

around 25 minutes.

Conclusion: The cycle time can be

reduced.

Conclusion about All case furnace:

Connected heat input is the most

important parameter for the All-case

furnaces. We can determine suitable allcase furnace for a specific load by

CHT-bf


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Application, Advantages and limitation of CHT- bf

Determination of pre-heat and cycle time

Helps in deciding appropriate furnace

Designing optimum load and its arrangement

Determination of required heat input of the furnace Low computation time make it highly applicable in industry

User friendly interface and stability further increases its applicability

Limitation

Scheduling more than one type of parts of different geometry andmaterial, we have to take average dimension and a closely resembling

material. This may affect the result.

Needs improvement for random load pattern

Part load may require some assumptions

Only applicable for heating process

Needs a furnace efficiency parameter


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Industrial Application of CHT- cf

Case studies performed at Bodycote ThermalProcessing, Waterbury, CT

Objective

To study the effects of change in the load quantity and givingrecommendations for the thermal schedule redesign.

To study the effect of change in load arrangement, determination ofoptimal load pattern from the calculated temperature values.

To study the effect of part orientation on the quality and distortion andhence to determine best suited load orientation.

To study the effect of belt speed and gross productivity on the thermalprofile of parts and hence determine optimum belt speed and loadcapacity to maximize productivity.

[ ] i [ ]bB d Sh


45/56

Mesh Belt Furnace

0051600Air505250004

0011600Air727000003

0001600Air728750002

000500Air1363000001

Through

metal

area

(in2)

Wall

Insulatio

n height(in)

Fan

Hors

epowe

r (HP)

Zone

temperat

ure(F)

Atmos

phere

content

Len

gth

(in)

Connecte

d heat

input(Btu/hr

)

Z

o

ne

90Furnace efficiency % (based on furnace age)

[ ] Yes [x ] NoVacuum Furnace

15Excess of preheated air (%)900Air preheated temperature (F)

Natural gasFuel

0Opening area of the end zone (in2)

324Opening area of the entrance zone (in2)

[x] internal [ ] externalBelt or conveyor return0.27Moving belt/conveyor unit weight (lbs/in2)

54Moving belt/conveyor width (in)

56 x 56Work space (Width Height)

Or (diameter ) (in)

90 x 96External size(Width Height)

Or (diameter ) (in)

[ ]Direct [x]indirect fired

[ ]electric

Heating type

[ ]pipe [x]boxBody Shape


46/56

Case study 1

0.04 lbsWeight

1020 carbon steelMaterial

XHD005 screwName

0.25 inchWorkpiece width

0.25 inchWorkpiece length

0.25 inchHeight of layers

0.156 inchWorkpiece height

54 inchActual load width

600 lbs/hrGross productivity


47/56

Result by CHT-cf & Measured result

Measured result

0

200

400

600

800

1000

12001400

1600

1800

0 20 40 60 80

Time (min)

Temp(F)

Channel 5 (Left)

Channel 1 (Right)

Channel 3 (center)


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C d 2 (d i diff l d


49/56

Case study 2 (demonstrating different load

patterns)

0.02Work piece weight (lbs)1020 carbon steelWork piece Material

14004 standard screwWork piece Name

0.125Workpiece height

2Workpiece width

2Workpiece length

0.375Height of layers (in)

54Actual load width (in)

600Gross productivity

(lbs/hr)

R d l d


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Random load

Arranged load


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Arranged load

Manual load arrangement

Arranged load clubbing 15 parts as 1.

Weight, part load pattern changed accordingly

Improvement in result


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Improvement in result

Uniformity of thermal profile in load

Better quality achieved (confirmed by the quality department)

Application and advantages of CHT cf


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Application and advantages of CHT- cf

The affect of part load arrangement can be studied using CHT-cf, prior torunning the actual load. As shown in the case studies uniformity oftemperature can be achieved by choosing arranged load pattern.

Orientation of parts: We can judge the part orientation, which givesuniformity in temperature

The affect of belt speed on the thermal profile of parts can be studied,and the optimum belt speed (i.e cycle time ) can be determined.

Furnace Planning: CHT-cfcan help us in determining the importantparameters required for the furnace, e.g connected heat input required for

each zones, which can help in deciding the number of burners requiredfor each zones.

Limitation of CHT cf


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Limitation of CHT-cf

In the Atmosphere content, only atmosphere name can be mentioned. Nooption to quantify the atmosphere content.

While simulating the part load by CHT-cf, distortion of parts are notconsidered, while in actual industrial practice the cycle time, productionrate and load pattern arrangement are mostly considered keeping in viewthe final quality and distortion.

Need to make the program stable and user friendly. Sometimes it givessome extra profiles in the temperature-time chart.

Summary


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Summary

Several case studies validated with experimental results (using thermocouple)

Accuracy of the temperature profiles predicted by CHT-bfand CHT-cf

Judgment and approximation required in defining part load

Described the methods to troubleshoot CHT-bfand CHT-cf

Discussed in detail all the features

i.e, database management

Case studies and the experience

helped in development ofCHT- q/tas well

Motivation to work closely

with industries


56/56

Thanks for your attention

QUESTIONS ?

Documents

Thesis Amajit