Publication

Abstract : Duplex stainless steel clad metals contain delta ferrite, which is expressed in terms of Ferrite Number (FN). The amount of ferrite present in the deposit is a function of chemical composition of the filler and base metals, welding process, type of shielding gas, welding procedure, and heat input during cladding. Excessive ferrite in duplex stainless steel claddings can result in poor ductility, toughness, and corrosion resistance. Likewise, insufficient ferrite can also produce inferior mechanical and corrosion resistance properties. Hence, control of ferrite in duplex stainless steel cladding is essential to obtain the required mechanical and corrosion-resistant properties. This paper highlights the application of response surface methodology to develop mathematical models and to analyze various effects of flux cored arc welding (FCAW) process parameters on the FN of duplex stainless steel clad metals. The experiments were conducted based on four-factor, five-level, central composite rotatable design with full replications technique and mathematical models developed using multiple regression technique. The developed mathematical models are very useful for predicting and controlling the FN in duplex stainless steel cladding. The main and interaction effects of input process parameters on calculated FN (by WRC-1992 diagram) and measured FN have been presented in graphic form, which helps in selecting FCAW process parameters to achieve the required FN.