The influences of weld metals on the weldability of SUPER 304 H steel were reviewed. The results show that the hot crack tendency of GTAW austenitic weld with different composition of super 304 H steel is relatively large;the solidification crack tendency in the weld is mainly controlled by a solidification mode

while the main reason of HAZ liquefaction crack tendency is related to the precipitation phase at the grain boundary and copper enrichment and other factors. The mechanical properties of austenitic weld joints with different compositions are different. Proper weld chemical composition and optimized welding process are an important technical means to obtain satisfactory comprehensive mechanical properties of joints.The microstructures of "similar" or "dissimilar" welds formed by different compositions are all austenite + precipitates. Fusion welds are solidified in A mode

while friction welds that are not fusion welded are solidified or phase-transformed in AF mode.