“…However, after welding, the HAZ experiences a rapid cooling rate (~10 3 to 10 7 K/s), which directly controls the solidification mode, and thus has considerable implications on the resultant microstructure [1]. Specifically in austenitic steels, a fine-grained dendritic microstructure is likely to form [2,3], and a phase transformation from austenite to martensite is favorable [4]. However, the predominant phase in the HAZ is austenite with a portion of δ ferrite, dependent on the weld material and solidification mode [5].…”