International Journal of Research ISSN NO:2236-6124ijrpublisher.com/gallery/128-april-1073.pdf · extensive system should be created all along the border to prevent Pakistan from

Controlling Wear via Hardfacing of Dragline Bucket Tooth

Sreejith NV, GurbhinderSingh

Department of Mechanical Engineering

Guru Kashi University, Talwandi Sabo, Bathinda, Punjab, India

Abstract: An extensive system proposed along the border to prevent Pakistan from rushing the border defences to

develop deeper thrusts towards the interior of India. This defensive systemis known as the ditch-cum-bund (DCB)

type of defence. Draglines are heavy equipments used to clear the DCBs (Ditch Cum Bund)in border area especially

in Punjab and Jammu regions. The high wear rate of its bucket teeth is the main problems faced in these

machines.The hardfacing is applied to metal parts to reduce the wear problems. In this research article, three

different types of electrodes are used for hard facing of draglines teeth made of low alloy steel is used. The

hardfacing process with the electrodes was effective in reducing the wear on the dragline teeth.The wear rate of the

OK 84.84 and Cobalarc-9 hard faced dragline teeth is less than the regular dragline teeth. The OK84.84 hard facing

electrode is much more economical as compared to the cobalarc-9 hard facing electrode. The wear rate found related

to both on hardness and chemical composition of the materials.

1. Introduction

A dragline is a massive earthmoving machine. It is predominantly used in making of Ditch cum Bund and in open-

cast coal mines. The larger draglines are used in strip mining to remove the soil layers covering coal. The smaller

machines may be used to de-silt canals and dams. Draglines are used where the burden that is excavated, must be

transported over a short distance only i.e. maximum approximately 100m.In 1971, Lt. Gen. P.S. Bhagat proposed an

extensive system should be created all along the border to prevent Pakistan from rushing the border defences to

develop deeper thrusts towards the interior of India [1]. He created a defensive system in Punjab which later came to

be known as the ditch-cum-bund (DCB) type of defence. Draglines are heavy equipments used to clear the DCBs

(Ditch Cum Bund)in border area especially in Punjab and Jammu regions. One of the main problems faced in these

machines is the high wear rate of its bucket teeth. In this research a dragline teeth made of low alloy steel is used. To

increase the wear resistance three different types of electrodes are used for hard facing of draglines teeth. A wide

variety of hard facing alloys is commercially available for protection against wear. Deposits with a microstructure

composed by disperse carbides in austenite matrix are extensively used for abrasion applications and are typically

classified according to the expected hardness. Nevertheless, the abrasion resistance of a hard facing alloy depends

on many other factors such as the type, shape and distribution of hard phases, as well as the toughness and strain

hardening behaviour of the matrix. Chromium-rich electrodes are widely used due to low cost and availability;

however, more expensive tungsten or vanadium-rich alloys offer better performance due to a good combination of

hardness and toughness. Complex carbides electrodes are also used; especially when abrasive wear is accompanied

by other wear mechanisms. Several welding techniques such as oxyacetylene gas welding (OAW), gas metal arc

welding (GMAW), shielded metal arc welding (SMAW) and submerged arc welding (SAW) can be used for hard

facing. The most important differences among these techniques lie in the welding efficiency, the weld plate dilution

and the manufacturing cost of welding consumables. SMAW, for example, is commonly used due to the low cost of

electrodes and easier application.

3. Experimental Procedure

3.1 Selection of Materials

In this research a dragline teeth made of low alloy steel is used which is shown in Fig. 1 and chemical

composition of this teeth is given in Table 1. To increase the wear resistance, three different types of electrodes are

used for hard facing of draglines teeth, which are given below. Chemical composition of these electrodes is given in

Table 2 and camera image of electrodes may be seen in Fig. 2.

International Journal of Research

Volume VIII, Issue IV, April/2019

ISSN NO:2236-6124

Page No:1113

i. ESAB Cobalarc-9

ii. ESAB OK 84.84

iii. ESAB OK84.78

Fig 1: Dragline Teeth

Table 1: Composition of the Dragline Teeth

Sr. No. Element Percentage

1 Carbon 0.33%

2 Manganese 1.28%

3 Silicon 0.28%

4 Chromium 0.17%

5 Molybdenum 0.22%

Table 2: Chemical Composition of Electrodes used for hard facing

Sr. No. Element

Electrode Materials

C Mn Si Cr Mo V Ti Fe

ESAB Cobalarc-9 4 1.2 1 30 1.9 --- --- Balance

ESAB OK 84.84 3 --- 2 8 --- 6 6 Balance

ESAB OK 84.78

4.5 1 0.8 31.8 --- --- --- Balance



ISSN NO:2236-6124

Page No:1114

Fig. 2 Electrons used for hard facing

3.2 Hard facing by shielded metal arc welding (SMAW)

Hard facing of Dragline Teeth was done by SMAW using three types of electrode shown in Fig. 2 and set up for

SMAW may be seen in Fig. 3. Specifications of SMAW are given in Table 3.

Fig 3: ESAB SMAW Welding Equipment

Table 3 Specifications of SMAW



ISSN NO:2236-6124

Page No:1115

Sr. No. Make and Type ESAB S3.8G4

1 Model EDW 400

2 Open circuit voltage 90V

3 Welding Current range 10-400 A

4 Electrode size 5 mm / continuous

3.3 Hardness Test

To measure the hardness of the specimens the Rockwell Hardness test (ASTM E18-17e1) was done. The averages of

six readings were taken to obtain the HRC number.

3.4 Dry Sand Rubber Wheel Test (DSRW)

The basic dry sand rubber wheel equipment(ASTM-G65) machine consists of a rubber-rimmed steel wheel, 228.6

mm in diameter by 12.7 mm wide, that turns at 200 rpm during a test; a sand hopper connected by a tube to a nozzle

that allows a maximum of 350g/min sand flow; a revolution counter that stops the drive motor after a set number of

revolutions; and a weighted lever arm that holds the specimen and produces a horizontal force against the wheel

where the sand is flowing. The sand is 50 to 70 mesh silica test sand.A test specimen is a rectangle, 25 by 76 mm

that is 3 to 13 mm thick. The wear surface is ground flat with a surface finish of at least 0.8 µm. The density of the

test material must be known, to calculate the volume lost. Set up of DSRW test is shown in Fig. 4 with schematic

diagram.

Fig 4 DSRW Test Set up

3.5 SEM/EDS Analysis

Scanning electron microscopes (ASTM F1372) is used to analyze the microstructure of the specimens. Secondary

electron imaging allowed morphologic description of the worn surfaces, while backscattered electron imaging and

EDS analysis was used to qualitatively describe chemical variations in the microstructure.

4. Results

4.1 Hardness



ISSN NO:2236-6124

Page No:1116

Hardness results are given in table 4. It can be observed from the hardness results that Cobalarc-9 hard faced

specimen is having the maximum hardness.

Table 4 Hardness Results

Sr. No. Specimen HRC No.

1 Base material 32

2 OK 84.78 hard faced specimen 42

3 OK 84.84 hard faced specimen 48

4 Cobalarc 9 hard faced specimen 51

4.2 Dry Sand Rubber Wheel (DSRW) Test

This test was conducted under the above specified test conditions i.e. under the normal load of 20N, wheel speed of

150 rpm and flow rate of sand are 100 grams/min. Weight loss after 15 minutes was measured. After checking the

weight loss test was further conducted and after 15 minutes further weight loss was measured. Hence the test was

further conducted and after 15 minutes final weight loss was measured. Hence measured weight loss after three

successive turns is presented in table 5 and the variation of weight loss with time during these successive turns may

be understood by graph presented in Fig. 5.

Table 5: Wear Results

Weight Loss after 15

Mins

(in grams)

Weight Loss during

successive 15 Mins

(in grams)

Weight Loss during

further successive 15

Mins

(in grams)

Base material 0.0417 0.2348 0.1459

OK 84.78 0.1366 0.0922 0.1016

OK 84.84 0.1085 0.0747 0.097

Cobalarc-9 0.0793 0.07 0.0556

Fig. 5 Weight loss with Time



ISSN NO:2236-6124

Page No:1117

It is observed from the Fig. 6 that the wear rate of the base material specimen is higher than the hard faced

specimen. Among the hard faced specimens the Cobalarc-9 hard faced specimen is having minimum wear rate. It

also has highest hardness. Metallurgical properties such as hardness, toughness, microstructure and chemical

composition are an important influence on abrasive wear. Though the hardness of the OK84.84 hard faced specimen

was low as compared to the cobalarc-9 hard faced specimen, the rate of wear was not as high as expected.

Fig 6 The relation of wear rate and hardness

4.3 SEM/EDS Analysis

(a) Base (b) OK84.78



ISSN NO:2236-6124

Page No:1118

(c) OK84.84 (d) Cobalarc-9

Fig 7 SEM of (a) base material, (b) OK 84.78 hard faced specimen, (c) OK 84.84 hard faced specimen,(d)

Cobalarc-9 hard faced specimen.

From the analysis it is observed that in Cobalarc-9 hardfaced specimen, the presence of the presence chromium and

manganese causes the increase in the corrosion resistance. Hence it prevents the wear of the material from chemical

action. This increases the wear resistance of the cobalarc-9 hardfaced specimen.

The presence of the Vanadium in the OK 84.84 hardfaced specimen increases the hardness of the specimen.

Vanadium forms carbides at lower temperature, promotes ferrite in the microstructure and increase the toughness. It

increases the hardness of steels due to its effect on the type of carbide present. Also the presence of the chromium

increases the corrosion resistance of the specimen.

5. Conclusions

The following conclusions were made from the above study:

1. The relative abrasion wear of the draglines teeth can be tested by the Dry sand rubber wheel test.

2. The wear rate of the OK 84.84 and Cobalarc-9 hard faced dragline teeth is less than the regular dragline

teeth.

3. The hardfacing process with the electrodes was effective in reducing the wear on the dragline teeth. It is

possible to reduce the wear by hardfacing the dragline teeth by the process shielded metal arc welding.

4. The Cobalarc-9 hard faced specimen is having minimum wear rate as compared to the other hard faced

specimen.

5. When cost is taken into the consideration the OK84.84 hard facing electrode is much more economical as

compared to the cobalarc-9 hard facing electrode.

6. The wear rate is related to both on hardness and chemical composition of the materials.

References

1. Evaluation of Indian military concepts, retrieved from

http://www.indiandefencereview.com/spotlights/evolution-of-indian-military-concepts/4/

2. Bellman, R., and Levy, A., “Erosion mechanism in ductile metals.” Wear 70,1-27, 1981.

3. S.W. Huang, M. Samandi, M. Brandt,”Abrasive wear performance and microstructure of laser clad WC/Ni

layers, Wear 256 (2004) 1095–1105.

4. R.C.D. Richardson, “The wear of metals by hard abrasives”, Wear 10 (1967) 291–309.

5. Hardfacing Information, Cigweld, SPW group Pvt. Ltd.

6. Gregory, Hardfacing, Tribology international, April 1978.



ISSN NO:2236-6124

Page No:1119

7. Kalpakjianschmid, Manufacturing Engineering and Technology, 6th-edition, Pearson Publication.

8. P.N. Rao, Manufacturing Technology, vol 1, Tata McGraw-hill Education, 2013.

9. A. Pearce, Farm and Workshop Welding, 2nd Edition, 5M Enterprises, 2006.

10. Repair and Maintenance Welding Handbook, Second Edition, ESAB.

11. J. Wang, L. Zhang, B. Sun, and Y. Zhou,”Study of the Cr3C2NiCr Detonation Spray Coating”, Surf. Coat.

Technol., 2000, 130(1), p 69-73.

12. Vencl, “Investigation of Abrasive wear resistance of ferrous based coatings with scratch tester”, Tribology

in industry, Vol 29, 2007.

13. Kennedy, “Methods of wear testing for advanced surface coatings and bulk materials”, Journal of material

processing technology 77, 1998.

14. Air jet tester manual, Bharat heavy electronics limited, 2006.

15. Guidance notes on test specimens, George prints, 2006.

16. A.R. Annappa and S. Basavarajappa,” Some studies on three body abrasive wear behaviour of hard faced

and normal plough tool material using Taguchi method”, Int. J. Surface Science and Engineering, Vol. 7,

No. 1, 2013.

17. Jie-Hao Chen,”Microstructure and Abrasive Wear Properties of Fe-Cr-C Hardfacing Alloy Cladding

Manufactured by Gas Tungsten Arc Welding (GTAW)”, Met. Mater. Int., Vol. 19, No. 1 (2013), pp.

93~98.

18. Amardeep Singh Kang, Jasmaninder Singh Grewal,” Wear Behavior of Thermal Spray Coatings on

Rotavator Blades”, Journal of Thermal Spray Technology Volume 21(2) March 2012—355.

19. Patrick W. Leech,”Comparison of abrasive wear of a complex high alloy hardfacing deposit and WC–Ni

based metal matrix composite”, Wear 294–295 (2012) 380–386.

20. Christian Egidio da Silva,”Abrasive Wear of Fe-Mn-Si-Cr-Ni Shape Memory Stainless Steel: Preliminary

Results”, Journal of Materials Engineering and Performance Volume 20(4–5) July 2011—679.

21. G.R.C.Pradeep, A.Ramesh, B.Durga Prasad,” A Review Paper OnHardfacing Processes And Materials”,

International Journal Of Engineering Science And Technology Vol. 2(11), 2010, 6507-6510.

22. John J.Coronado, HolmanF.Caicedo, AdolfoL.Gomez,” The effects of welding processes on abrasive wear

resistance for hardfacing deposits”, Mechanical Engineering School, Universidad del Valle, Cali,

Colombia, Tribology International 42 (2009) 745–749.

23. Z. Horvata, D. Filipovicb,, S. Kosuticb, R. Emertc,”Reduction of mouldboard plough share wear by a

combination technique of hardfacing”, Tribology International 41 (2008) 778–782.

24. XinhongWang,”Microstructure and wear properties of the Fe–Ti–V–Mo–C hardfacing alloy”, Wear 265

(2008) 583–589.

25. YilmazBayhan ,”Reduction of wear via hardfacing of chisel ploughshare”, Department of Agricultural

Machinery, Tekirdag Agricultural Faculty, University of Trakya, 59030 Tekirdag, Turkey, Tribology

International 39 (2006) 570–574.

26. M.F. Buchely, J.C. Gutierrez, L.M. Leon, A. Toro,” The effect of microstructure on abrasive wear of

hardfacing alloys”, Tribology and Surfaces Group, National University of Colombia, Medellın, Colombia,

Wear 259 (2005) 52–61.

27. B. Bhushan,” Tribology and Mechanics of Magnetic Storage Devices”, Springer-Verlag New York, Inc.

1996.

28. J.L. Henderson,” Alloy classification of hardfacing materials”, International journal pres. ves. & piping,

47(1991),127-158.

29. K.Allen, “Coatings to improve the wear resistance of low alloy steels”, Tribology International, Vol. 9,

1986.

30. P.L. Hurricks, “Some aspects of metallurgy and wear resistance of surface coatings”, Wear,22,1972.



ISSN NO:2236-6124

Page No:1120

Documents

International Journal of Research ISSN NO:2236-6124ijrpublisher.com/gallery/128-april-1073.pdf · extensive system should be created all along the border to prevent Pakistan from