Effects of welding on the microstructural properties of AISI 43 ferritic stainless steel

Ferritic stainless steel (FSS) are engineering alloys with high strength, improved ductility and better corrosion resistance in environments containing various compounds of chloride, normally experienced in petrochemical and nuclear power industries. However ferritic stainless steel suffer some weldability issues like grain growth at heat effected zone (HAZ), martensite and carbide formation at grain boundaries, sensitization and intergranular stress corrosion cracking. In this study AISI 430 butt TIG welding is investigated for these issues. The investigations reveal the presence of martensites and carbides in the grain boundaries along with coarse grain structure in HAZ and FZ. The increased hardness and strength at weld zone causes FSS to have low ductility and prone to cracking in stress environment