Influence of Heat input on Corrosion Resistance of Duplex Stainless Steel Cladding using Flux Cored Arc Welding on Low Alloy Steel Flats

Cladding is deposition of material on a corrosion-prone substrate to protect it from corrosion. Duplex stainless steel cladding is reported to have the ability to offer good corrosion resistance. In the present work, duplex stainless steel (E2209 T0-1) filler material is used for depositing a single layer with 50% overlap on E250 low alloy steel substrate using FCAW process with 100% CO as shielding gas. Three sets of heat input are chosen for the 2 experiment. Each set has different welding voltage and current, whereas travel speed has been kept constant for all experimental runs. Experiments have been replicated twice. 24-hour accelerated corrosion test is conducted on the clad surface in ferric chloride and hydrochloric acid solution. Results obtained from corrosion test indicate that all clad parts have better pitting corrosion resistance than the base metal. Corrosion resistance of clad parts exhibits decreasing tendency with greater heat input on the whole. Polynomial regression analysis is used to establish the quadratic relationship between heat input and pitting corrosion rate that indicate corrosion rate to increase with increase in heat input. ANOVA table depicts that the results obtained in pitting corrosion test against different heat input conditions are significant with high (95%) confidence level. The value of R2 (0.7014) indicates fairly good association between heat input and corrosion rate.