Effect of heat input on microstructure and mechanical properties of ultra-thin 443 ferritic stainless steel

Tungsten inert gas (TIG) welding,pulsed tungsten inert gas (P-TIG) welding and pulsed laser beam welding (P-LBW) of ultra-thin 443 ferritic stainless steel sheets were conduted to investigate the problems of coarsened grain and brittleness in the weld.The effects of different welding processes on the microstructure and mechanical properties of resultant joints were analyzed with optical microscope (OM) and scanning electron microscope (SEM).The effects of welding heat input on microstructure,tensile property and cupping property of joints were evaluated.The experimental results reveal that the welding heat input was the key factor to determine the microstructure and mechanical properties of 443 ferritic stainless steel welded joints.And grain refinement by pulsed welding process can improve the comprehensive mechanical properties of the resultant joint.