Effect of molybdenum on low temperature toughness of austenitic stainless steel weld metals - low temperature toughness of austenitic stainless steel weld metal (report 6)

The effect of molybdenum on notch toughness of austenitic stainless steel weld metal was investigated. The weld metals where molybdenum content varied from 0.1 to 2.9% and δ ferrite content 0 to 10.8%, were prepared by submerged arc welding. The absorbed energy of fully austenitic weld metal was constant independent of molybdenum content. However, in the case of eutectic δ ferrite weld metal, the absorbed energy decreased monotonously with molybdenum content. In the weld metal of primary δ ferrite, the absorbed energy was constant up to 2.3% Mo and began to drop in the specimen above 2.9% Mo where the concentration of molybdenum within the δ ferrite grain was more than 5%. Multiple regression analysis revealed that C, Cr and Mo had a reducing action on toughness.