Abstract: Structure and mechanical properties of Co-Ni-Cr-Mo secondary hardening ultra-high strength steel 0. 16C, 11.0Ni,2.0Cr,3.0Mo,14.0Co melted by a 25 kg induction furnace and aged at 460~580 ℃ have been studied. Test results showed that with 860 ℃ quenching + cold treatment at -73 ℃+ aging at 480 ℃,there was large amount dispersed acicular M(Co,Mo)₂C precipitates in structure of steel, yield strength Rp_0.2 of steel was up to maximum value 1685 MPa, impact energy A_kv was 20 J; with overaged condition at 550 ℃,as amount of reverse transformation austenite at lath boundary obviously increased,A_kv increased to 32 J and Rp_0.2 decreased to 1320 MPa.

摘要： 研究了25 kg感应炉熔炼的Co-Ni-Cr-Mo二次硬化超高强度钢(％:0．16C、11．0Ni、2．0Cr、3．0Mo、14．0Co)经460-580℃时效后的组织和力学性能。试验结果表明,该钢经860℃淬火+(-73℃)冷处理+480℃时效后,组织中存在大量弥散分布的针状M(Co,Mo)₂C碳化物,钢的屈服强度Rp_0.2达到最大值1 685 MPa,冲击功A_kv为20 J;在550℃过时效状态下,板条边界逆转变奥氏体量明显增加,A_kv增至32 J,同时Rp_0.2下降至1 320 MPa。

关键词:  , 14Co- 11Ni-2Cr-3Mo 超高强度钢,时效温度, 组织性能