Enhancement of strength and ductility by Cu-rich precipitation in Cu-bearing 304L austenitic stainless steel

This work investigated the effects of copper (Cu) addition and Cu-rich precipitates on the deformation mechanism and strain hardening behavior of 304L austenitic stainless steel. The results indicated that high addition of Cu could suppress the formation of martensite and improve the amount of deformation twins after tensile deformation, which was accordance with the calculated stacking fault energies. After aging treatment, the finely dispersed Cu-rich precipitates were involved in the deformation process and retarded the decreasing tendency of strain-hardening rate. The synergistic effects of transformation-induced plasticity (TRIP), twinning-induced plasticity (TWIP) and Cu-rich precipitation-induced plasticity were well homogenized and improved the excellent strength-ductility balance in 304L austenitic stainless steel.