Comprehensive analysis of welding parameters on surface modification process

Abstract

Surface modification is one of the metal working processes, which is used to alter the surface property of a base material by the depositing a filler metal on the surface. In recent days for improving the surface characteristics such as corrosion resistance and hardness of the older components, special filler materials were used for coating. This reduced the cost involved by replacing the existing component. In a sense, the cladding process plays a vital role for modifying the surface properties than replacing the new material with existing. Cladding is the surface modification processes based on the filler material deposition and penetration of melted filler material on the top surface of base material. newlineThis research work deals with the evaluation of cladding performance characteristics based on response surface methodology and genetic algorithm on medium carbon steel with super duplex stainless steel filler material. The empirical models were developed based on Taguchiand#8223;s L9 orthogonal array design of experiment concept with welding current, gas flow rate and welding speed as cladding parameters. The responses were hardness, corrosion rate, bead width, and penetration depth. Highest hardness of 137.4Hv, maximum bead width of 6.728 mm, maximum penetration of 2.016mm and minimum corrosion rate of 26.25 x 10-3 mils/year were observed. Current has influenced all the parameters by providing sufficient heat to the process. Higher value of hardness (137.26 Hv) was observed due to the development of pearlite structure in the metal. The current caused melting and deposition of large amount of cladding material thereby reducing the corrosion rate. Recrystallization of martensite structure inside the base metal have resulted for higher hardness at high temperature. Descending order of hardness as Cladded zone gt interface gt HAZ gt Base metal. The refining of grain structure happened due to proper maintenance of temperature gradient by lowering gas flow rate. newline