Depiction of Detrimental Metallurgical Effects in Grade 304 Austenitic Stainless Steel Arc Welds

Abstract

Efforts have been made to integrate fundamental microscopic behaviour and metallurgical transformations of Grade 304 Austenitic stainless steel during solidification. Incomplete mixing during solidification of Grade 304 steel in weld pool initiates segregation that encourages the dendritic envelope motion regulated by the enlargement of dendrite tips. High segregation of chromium and molybdenum, lead to the formation of secondary ferrite that increases tendency of accumulation of intermetallic phases. Micro and macro cracks with different orientations also occur in various sections of the weld, because of low melting liquid phases in the primary weld zone or enveloping HAZ. It aggravates grain boundaries to split under the thermal and shrinkage strain during metallurgical changes. Solid-state transformation of ferrite to austenite results in separation of solidification boundaries from grain boundaries thus reduces possibility of hot cracking. But probability of fissuring in the weld HAZ in fully austenite welds is higher than in ferrite containing welds. Contending variables adjoin complexity, hence the primary intention of this review is to correlate microstructural developments of Grade 304 steel under the influence of metallurgical variations.