关键词: 0Cr17Ni4Cu4Nb马氏体沉淀硬化不锈钢, Cu含量, 力学性能, 富Cu相

Abstract: The tested steel 0Cr17Ni4Cu4Nb (/%: 0.016~0.017C, 0.31~0.35Si, 0.79~0.85Mn, 0.009~0.012P, 0.008~0.010S, 15.29~15.43Cr, 4.10~4.15Ni, 3.34~4.92Cu, 0.25~0.27Nb) is melted by a 25kg vacuum induction furnace and forged to Φ18mm bar. The 3.34%~4.92% Cu content on phase transformation point of steel 0Cr17Ni4Cu4Nb, mechanical properties and structure of steel oil-quenched at 1040°C for 1h and oil-cooling aged at 460~610°C for 2h is tested and studied by mechanical properties measurement and structure analysis. Results show that with increasing Cu content in steel the effect of Cu content on Ac₃ is not obvious but the Ac₁ decreases in some extent, and the M_s point of steel moves up while the M_f point of steel comes down；with higher Cu content in steel the strength and hardness of steel is higher, but plasticity of steel is slightly lower；with control the Cu content in steel being minimum to middle of standard permissible variations, it is able to meet the mechanical properties requirement of specification, i. e. with aged at 460~500℃ the steel R_m≥1315MPa, R_p0.2≥1175MPa, A≥10% and Z≥40%.