Experimental Investigation And Parametric Optimization Of Automated Metal Inert Gas Welding Stainless Steel Ss 316 With Low Alloy Steel Aisi 4140

Abstract

In Today's Industry Such As Marine, Aerospace, And Automotive Engineering, Components Need To Be Made Out Of Materials That Have Different Properties In Order To Meet Specific Performance Requirements. Stainless Steel 316 And Low Alloy Steel 4140 Are The Most Commonly Used Materials In Marine Industry Where Corrosive Resistivity And High Specific Strength Is The Design Requirement. This Was The Main Importance Of Welding Dissimilar Metal Using Automated Mig To Improve Quality And Reliability. This Thesis Was Aimed To Study How Different Mig Process Parameters (Welding Current, Wire Feed Rate, Gas Flow Rate, And Welding Speed) Affects The Mechanical Properties, Bead Geometry, Percentage Of Surface Defects, Corrosion Resistivity, And Microstructural Properties Of Welding Two Different Metals Together Namely Stainless Steel 316 And Low Alloy Steel 4140. Taguchi L9 Orthogonal Array Was Used As Design Of Experiment And Multi-Response Optimization Was Conducted Based On Taguchi Grey Relational Analysis. To Study The Significance And Contribution Of Each Parameter, Analysis Of Variance (Anova) Were Conducted Using Minitab 21 Software. Liquid Penetrant Was Used To Evaluate The Welding Defects According International Welding Defect Criteria Of Aws (American Welding Society). The Result Of Microstructure Analysis Shows The Presence Of Skeleton??-Ferrite And Twins With Fine Grain Structure. The Result Obtained From The Corrosion Test Was Revealed That The Corrosion Resistivity Of The Weld Zone Was Higher Than The Base Metal Of Aisi 4140, Heat Affected Zone Of Aisi 4140, And Ss 316 By17.30%, 41.30%, And 12.84% Respectively. The Tensile Strength And Flexural Strength Experimental Result Showed That Welding Current Parameter Has High Significant Effect In Both Cases Followed By Welding Speed. Hardness Result Shows That The Welding Speed Followed By Welding Current Has A Significant Effect On Hardness. The Result From Study Of Bead And Surface Defect Shows That Welding Current Has A Significant Impact On Bead Quality And Percentage Of Surface Defects Followed By Welding Speed Grey Relational Analysis Of Multi-Responses Optimization Result Shows That Welding Current Has A Highly Significant Effect, While Gas Flow Rate And Welding Speed Has No Significant Effect. Finally The Confirmation Test Result Reveals That The Experimental Result At The Optimum Parametric Setting Of Welding Current At Third Level (140a), Wire Feed Rate At First Level One (7cm/S), Gas Flow Rate At Second Level (9cfh), And Welding Speed At Level One (20cm/Min) (A3b1c2d1)Average Multi Responses Were Enhanced By 7.78% From The Initial Optimal Setting.