The dependence of crack properties on the Cr/Ni equivalent ratio in AISI 304L austenitic stainless steel weld metals

The crack properties and mechanical characteristics in AISI 304L stainless steel weld metals were evaluated by differentiating solidification mode using three newly designed filler wires with flux-cored arc welding (FCAW) process. Microstructure examination showed that the delta ferrite content in the deposited metals increased with an increasing equivalent ratio of chromium/nickel. Solidification cracking was observed in the first layer of deposited metal in the fully-austenite structure and its fracture surface was coated by a film of low-melting eutectics. Ductility-dip cracking (DDC) was propagated along the migrated grain boundary (MGB). The fracture surface of the DDC was shaped along the sharp ridgeline, and the preferential angle for the formation of DDC was 45° to the applied load.