Mathematical Modeling of Hard Facing Low Carbon Steel With Corrosive Nickel Based Alloy by Gmaw

MATHEMATICAL MODELING OF HARDFACING LOW CARBON

STEEL WITH CORROSIVE NICKEL BASED ALLOY BY GMAW

Under the Guidance of

Prof. C. Bhagyanathan AP/MFG

Assistant Professor

ByS. Santhosh(1066008)

INTRODUCTION

Corrosion and Wear are the major problems in metallic components. Wear occurs in the sliding contacts due to dynamic loading.

Both has drastic effects on the applications and costs on metallic components.

PROBLEM IDENTIFICATION

• Wear is the drastic effect on metal to metal contact parts so the life span of the part is short according to its service condition.

• Replacing the worn-out parts to new parts in all the time is not economic for industries.

• Most of the machine parts has weight to strength ration constrains within this limits the material property should be enhanced.

PROBLEM DEFINITION

• To create mathematical model for bonding Chromium-Cobalt alloy with Low Carbon Steel for GMAW process

• To optimize GMAW process parameters

• Validate the result by applying conformity test, corrosion test and wear test.

METHODOLOGY

Problem Identification

Literature Survey

Development of GMAW Setup

Development of Mathematical models for the prediction of weld bead geometry

LITERATURE SURVEY

Extended Abstract• The defect free deposits can be made without any preheating

by the GMAW process and the deposits has a more uniform.

1Effect of Welding Parameters on the Microstructure of Stellite-6 Deposits

Key words• GMAW, Microstructure, Stellite-6

Interception• Study on the GMAW process

Extended Abstract• Constant current characteristics were typically

advantageous for automatic welding, to provide sufficient accuracy and repeatability in current level from weld to weld.

2 Basics to know when choosing a GMAW and GTAW power source

Key words• GMAW, GTAW, Accuracy, Repeatability

Interception• Power supply characteristics of GMAW process

Extended Abstract• GMAW is the best suited for hardfacing small parts as it

produces high quality deposits.

3 Hardfacing – Past, Present, Future

Key words• GMAW, Hardfacing, Quality

Interception• Study the importance of hardfacing

Extended Abstract• Welding variables such as welding current, filler rod feed

rate, welding speed and even current mode have effect on surfacing deposit irrespective of process.

5 Hardfacing International Welding Journal

Key words• Welding parameter

Interception• Study on effect of welding variables on deposit rate

PARAMETERS

PARAMETERS

ParameterArc

Voltage

Wire Feed Rate

Welding Speed

Nozzle to Plate Distance

Unit Volt m/min cm/min cm

Notation V F S D

Level1 37 7 24 1.5

-1 27 4 10 1

DOE MATRIX

Trail No.

Process variables

Arc Voltage (V) Wire feed rate (F)Welding speed

(S)Nozzle to plate

distance (D)

01 -1 -1 -1 -1

02 1 -1 -1 -1

03 -1 1 -1 -1

04 1 1 -1 -1

05 -1 -1 1 -1

06 1 -1 1 -1

07 -1 1 1 -1

08 1 1 1 -1

09 -1 -1 -1 1

10 1 -1 -1 1

11 -1 1 -1 1

12 1 1 -1 1

13 -1 -1 1 1

14 1 -1 1 1

15 -1 1 1 1

16 1 1 1 1

RESPONSE

Trail No.Process variables Bead parameters

V F S D BW BH BP Di %

01 -1 -1 -1 -1 10.17 3.50 1.19 19.19

02 1 -1 -1 -1 9.51 4.40 1.06 25.35

03 -1 1 -1 -1 11.02 3.95 1.31 19.48

04 1 1 -1 -1 7.01 3.19 1.04 24.97

05 -1 -1 1 -1 9.52 2.74 1.29 24.50

06 1 -1 1 -1 7.85 3.64 1.16 31.92

07 -1 1 1 -1 9.97 3.19 1.41 24.18

08 1 1 1 -1 8.78 4.10 0.78 30.66

09 -1 -1 -1 1 10.89 3.65 1.03 15.95

10 1 -1 -1 1 9.62 4.55 0.90 21.97

11 -1 1 -1 1 11.13 4.10 1.15 16.57

12 1 1 -1 1 7.13 3.34 0.88 21.96

13 -1 -1 1 1 9.64 2.89 1.13 20.76

14 1 -1 1 1 7.97 3.79 1.00 28.01

15 -1 1 1 1 10.48 3.34 1.25 20.89

16 1 1 1 1 10.17 3.50 1.19 27.24

MATHEMATICAL MODEL

The response function representing any weld bead dimension can be expressed as,

  Y = f (V, S, F, D)Where,

Y = Response function.b0, bi = Regression co-efficient.

Xi = Parameters or variables.

  K

Y = b0 + Σ bi Xi

i=1

MATHEMATICAL MODEL

For four factors the selected polynomial (regression) equation could be expressed as:

Y = b0 + b1V + b2 F + b3 S

+ b4 D

REGRESSION COEFFICIENT

Coefficient Due to

Value

BW BH BP Dilution

b0 Combined effect of all parameters (Main effect) 2.450 4.801 0.345 5.436

b1 Arc Voltage 0.204 – 0.0450 0.025 0.631

b2 Wire Feed Rate 0.240 0.1500 0.042 – 0.070

b3 Welding Speed – 0.091 – 0.054 0.007 0.381

b4 Nozzle to Plate Distance 0.482 0.303 – 0.32 – 6.725

FINAL MATHEMATICAL MODELS

The final mathematical models as determined by the above analysis are presented below:

BW = 2.450 + 0.204 V + 0.240 F – 0.091 S + 0.482 D

BH = 4.801 – 0.045 V + 0.15 F – 0.054 S + 0.303 D

BP = 0.345 + 0.025 V + 0.042 F + 0.007 S – 0.32 D Dilution = 5.436 + 0.631 V – 0.070 F + 0.381 S – 6.725 D

INFLUENCE OF PROCESS PARAMETERS ON BEAD WIDTH.

• Arc Voltage, Wire Feed Rate and Nozzle to Plate Distance shows an positive influence on the bead width.• Welding Speed shows an negative influence on the bead width.• From the positive influencers the Nozzle to Plate Distance Plays major role

INFLUENCE OF PROCESS PARAMETERS ON BEAD HEIGHT

• Wire Feed Rate and Nozzle to Plate Distance shows an positive influence on the bead width.• Welding Speed and Arc Voltage shows an negative influence on the bead width.• From the positive influencers the Nozzle to Plate Distance Plays major role

INFLUENCE OF PROCESS PARAMETERS ON BEAD PENETRATION

• Arc Voltage, Wire Feed Rate and Welding Speed shows an positive influence on the bead width.• Nozzle to Plate Distance shows an negative influence on the bead width.• From the positive influencers the Nozzle to Plate Distance Plays major role

INFLUENCE OF PROCESS PARAMETERS ON DILUTION

• Arc Voltage, and Welding Speed shows an positive influence on the bead width.• Wire Feed Rate and Nozzle to Plate Distance shows an negative influence on the bead width.• From the positive influencers the Nozzle to Plate Distance Plays major role

CONCLUSION The primary objective of this dissertation is to develop

mathematical models for improving the weld bead quality using GMAW process, for FW-2 hardfacing on low carbon valve.

The mathematical models were developed using regression analysis and four factor two level design matrix is effectively used.

Mathematical models were developed for the following responses like Bead Height (BH), Bead Reinforcement (R), and Bead Width (W), The responses were related with process parameters, Arc Voltage (V), Wire Feed Rate (F), Welding Speed (S) and Nozzle to Plate Distance (D).

The Mathematical model indicates, the influence of Arc Voltage, Feed Rate, Welding Speed and Nozzle to Plate Distance on Bead Height, Bead Reinforcement and Bead Width

FUTURE RESEARCH FOR PHASE - II

This research has focused on developing mathematical modeling for GMAW process for Hardfacing FW-2 alloy on low carbon steel material.

The study can be extended to optimize the parameter. Study the corrosion and wear resistance of the low

carbon steel after hardfacing with FW-2 alloy. Future research studies need to investigate the different

alloys or processes which can be employed for depositing hardfaced layers.

REFERENCES

1. Albert S.K, Gowrisankar I, Seetharaman V, and Venkatesan S, “Effect of Welding Parameters on the Microstructure of Stellite-6 Deposits”, Proceeding of National Welding Seminar, IIW, Bangalore., Nov. 26-28, pp A1- A7.

2. Dennis Destefan, “Basics to know when choosing a GMAW and GTAW power source”, Welding Journal, pp 67-72.

3. Barr L.C. and Rogers C.E., “ Hardfacing – Past, Present, Future”, Welding Journal, pp 968-974.

4. Foroulis Z.A, “ Guidelines for the selection of hardfacing alloys for Sliding Wear Resistance Application”, TMS –AIME, New York, pp. 203-218.

5. Quaas J.F., “Hardfacing International Welding Journal”, pp.175-182.