【摘要】 为研究Cu元素对125 ksi钢级15Cr马氏体不锈钢组织与力学性能的影响，利用光学显微镜（OM）、扫描电镜（SEM）、透射电镜（TEM）、洛氏硬度计以及电子万能试验机等研究了500～550℃回火后1.00%～1.50%Cu试验钢的显微组织与性能的变化。结果表明：1.00%～1.50%Cu试验钢的显微组织和SEM图像没有明显差异，通过TEM观察可知，随Cu含量的增加，马氏体板条逐渐粗化，强化作用增强，抗回火能力变弱。试验钢中的析出相主要为Laves相、χ相、σ相、少量M₂₃C₆以及微量富Cu相，且随着Cu含量的增加，奥氏体相区逐渐扩大。富Cu相的析出温度随Cu含量的增加由667℃逐渐提高为706℃,析出量由0.008增至0.012,由椭球状转变为棒状。钢中Cu含量的增加，对χ相、Laves相以及M₂₃C₆相的影响不大。Cu含量按1.25%控制较合适，控制范围在1.20%～1.40%,可以在较宽泛的回火工艺范围内调整强度与韧性。更多还原

【Abstract】 To investigate the effect of Cu element on the microstructure and mechanical properties of 125 ksi grade 15Cr martensitic stainless steel, the changes in microstructure and properties of 1.00%-1.50%Cu tested steels tempered at 500-550 ℃ were studied by means of optical microscope（OM）, scanning electron microscope（SEM）, transmission electron microscope（TEM）, Rockwell hardness tester, and electron universal testing machine. The results show that there is no obvious difference between the metallographic structure and SEM images of 1.00%-1.50% Cu tested steels. The TEM observation shows that with the increase of Cu content, the martensitic lath gradually coarsens, the strengthening effect increases, but the tempering resistance weakens. The precipitated phases in the tested steels are mainly Laves phase, χ phase, σ phase, a small amount of M₂₃C₆, and trace amounts of Cu-rich phase, and the austenite phase region gradually expands with the increase of Cu content. The precipitation temperature of the Cu-rich phase gradually increases from 667 ℃ to 706 ℃ with the increase of Cu content, and the precipitation amount increases from 0.008 to 0.012, transforming from ellipsoidal to rod-shaped. The increase of Cu content in the tested steel has little effect on the χ phase, Laves phase, and M₂₃C₆ phase. It is more appropriate to control the Cu content at 1.25%, and with a control range of 1.20% to 1.40%, which can adjust the strength and toughness within a wide range of tempering processes.更多还原