ROLE OF FERRITE AND PHOSPHORUS PLUS SULPHUR IN THE CRACK SENSITIVITY OF AUTOGENOUSLY WELDED TYPE 309 STAINLESS STEEL

摘要

A study on autogenous welding of Type 309 thin stainless steel sheet was made after experiencing cracking difficulties on several commercial heats.nA relationship exists between the sum of the phosphorus plus sulfur, the ferrite control of the weld metal, and the crack sensitivity of autogenously made welds. A new simple weld test for thin-gage sheet is utilized for studying the susceptibility to cracking. A chemistry modification is suggested to alleviate possible weld cracking when autogenously welding this grade. The principles of crack sensitivity prediction could apply to other austenitic stainless steel types where chemistry limits are such that ferrite is possible.