Microstructure and Mechanical Properties in Welded Joint of High Purity Cr30Mo2 Ferritic Stainless Steel

A welding bench was designed.By using it a new type of high-purity ferritic stainless steel was welded based on TIG.The welded joints of Cr30Mo2 ferritic stainless steel were formed by the argon arc welding with stretching argon shielding behind nozzle.The qualities of welded joints were carried on by visual examination and X-radiographic inspection.Microstructure of welded joint was investigated by means of metalloscope.Impact fracture morphologies were analyzed by making use of scanning electron microscope(SEM) and transmission electron microscope(TEM).The joint mechanical properties were measured according to national standard.The results showed that any weld defects were not found in welded joint.Mechanical properties of welded joint were in good agreement with the base metal,especially,the plastic and impact toughness properties on the weld metal and heat affected zone(HAZ) were not decreased.Toughness fracture micromorphology characters were found in heat-affected zone of welded joint.