摘要
采用力学性能试验和金相显微镜（OM）、扫描电子显微镜（SEM）等显微组织分析方法对一种高Co-Ni含量二次硬化钢25Co15Ni11Cr2MoE淬火后,经200~750℃回火后的力学性能和冲击断口形貌的变化规律进行了分析研究,结果表明：25Co15Ni11Cr2MoE试验钢淬火＋回火后具有明显的二次硬化效应,在400~495℃范围内,回火后的硬度值均高于淬火态硬度值;随着回火温度的提高,钢的抗拉强度、屈服强度和硬度均不断增加,在470℃回火后,试验钢的硬度和抗拉强度均达到了极大值57.3HRC和2160MPa;而冲击韧性值随着回火温度的升高先降低,在430℃达到极小值,随后逐渐提高,并在510℃回火后达到极大值。建议25Co15Ni11Cr2MoE钢的最佳热处理制度为：950℃×1h油冷＋（-73℃）×1h空气中升温至室温＋495℃×5h空冷,此时试验钢具有最佳的强韧性匹配。
The change rule of mechanical properties and impact fracture morphologies of a high Co-Ni secondary hardening ultra-high strength 25Co15Ni11Cr2MoE steel tempered at 200-750℃ after quenched was studied by mechanical properties test and microstructure analysis such as optical microscope（OM）and scanning electron microscope（SEM）.The results show that experimental steel after quenching and tempering has a remarkable secondary hardening effect.After tempered at 400-495℃,the hardness of experimental steel can reach and beyond the quenched hardness.In this range,tensile strength,yield strength and hardness of experimental steel increase with the tempering temperature increasing,tensile strength and hardness of experimental reach maximum（57.3 HRC and 2 160 MPa）after tempered at 470℃,meanwhile,with the tempering temperature increasing,impact toughness of experimental steel decreases during the prophase,until reaches minimum at 430℃,then increases gradually,and reaches maximum after tempered at 510 ℃.The recommended optimum heat treatment process of 25Co15Ni11Cr2 MoE steel is as follow：950℃×1 hoil quenching＋（-73℃）×1 hrising back to room temperature in the air＋495℃×5 hair cooling.At this time,the experimental steel has the best strength and toughness matching.
作者
廉学魁
厉勇
王春旭
刘宪民
LIAN Xue-kui;LI Yong;WANG Chun-xu;LIU Xian-min(Department of Science and Technology Operation, Central Iron and Steel Research Institute, Beijing 100081, China;Institute for Special Steel, Central Iron and Steel Research Institute, Beijing 100081, China)
出处
《钢铁研究学报》
CAS
CSCD
北大核心
2018年第5期386-391,共6页
Journal of Iron and Steel Research
关键词
回火温度
二次硬化
力学性能
强韧性
冲击断口
tempering temperature
secondary hardening
mechanical property
strength-toughness
impact fracture
