Enhancement of Strength–Ductility Balance of the Laser Melting Deposited 12CrNi2 Alloy Steel Via Multi-step Quenching Treatment

A ferrite–austenite 12CrNi2 alloy steel additively manufactured by laser melting deposition (LMD) was heat treated direct quenching (DQ) and tempering inter-critical (TIQ) at 800 °C for enhancing its strength–ductility balance. Both heat-treated steels have the martensite–ferrite dual-phase (DP) microstructures. The volume fractions of martensite in two are nearly similar (~ 85 vol%), while sizes prior austenitic grain different. martensite-dominated DP microstructure resulted an obvious improvement balance steel. Compared with DQ treatment, multi-step TIQ treatment caused to be enhanced due higher total elongation. better ductility TIQ-treated can attributed optimization microstructure. preferred orientation ferritic as-deposited which adverse plastic deformation through dislocation slip eliminated via treatment. Moreover, promoted formation finer-grained larger areas boundaries twinning enhancement coordinated deformability ferrite.