Effect of ferrite morphology on pitting corrosion resistance of austenitic stainless steel weld metals

The effect of the ferrite morphology on the pitting corrosion resistance of austenitic stainless steel weld metals solidified with primary ferrite was investigated. Most of the pitting corrosion occurred at the interface between ferrite and austenite-particularly at the vermicular ferrite/austenite interface; less pitting corrosion occurred at the lacy ferrite/austenite interface. This was because a Kurdjumov-Sachs orientation relationship was established between lacy ferrite and austenite. Consequently, Cr carbide was less likely to precipitate owing to the low interfacial energy, and the lacy ferrite/austenite interface was less likely to be an initiation site of pitting corrosion.