材料工程2025，Vol.53Issue(11)：90-100,11.DOI:10.11868/j.issn.1001-4381.2024.000079
不同淬火温度对节Co型2.2GPa级超高强度钢组织及力学性能的影响
Effect of different quenching temperatures on microstructure and mechanical properties of Co-conserving 2.2 GPa grade ultra-high strength steel
摘要
Abstract
The desirable combination of ultra-high strength and good toughness enables the secondary hardening ultra-high strength steel widely used in aerospace and energy equipment.The influence mechanism of quenching temperatures on the microstructure and mechanical properties of Co-conserving 2.2 GPa ultra-high strength steel is investigated by using scanning electron microscope(SEM),transmission electron microscope(TEM),tensile and impact testing machine.The results show that when the quenching temperature is 950℃,there are many undissolved M6C carbides and unrefined grains in the matrix,resulting in lower strength(tensile strength:2072 MPa,yield strength:1873 MPa).As the quenching temperature increases,recrystallization promotes the refinement of the matrix grains,and the number of M6C carbides gradually decreases;such partial dissolution favors the precipitation of hardening phases,resulting in a recovery of strength;when the quenching temperature is 1030℃,the experimental steel has excellent combination of strength-plasticity-toughness:the tensile strength is 2251 MPa,the yield strength is 1901 MPa,the elongation is 9%,and the V-notch impact absorbed energy is 9 J.By further increasing the quenching temperature,the rapid growth of austenite grains leads to severe plasticity attenuation,with elongation of only 4.5%at 1120℃.Between 1030-1090℃,there is a competitive relationship between the dissolution of M6C carbides and grain growth.Although higher temperature quenching promotes dissolution,the severe coarsening of grains offsets the former's beneficial effect on toughness to enable a stable performance of strength and toughness.关键词
超高强度钢/淬火温度/碳化物/奥氏体晶粒/强塑性Key words
ultra-high strength steel/quenching temperature/carbide/austenite grain/strength and plasticity分类
金属材料引用本文复制引用
王飞腾,米鹏,张洪林,李鑫扬,徐斌,孙明月..不同淬火温度对节Co型2.2GPa级超高强度钢组织及力学性能的影响[J].材料工程,2025,53(11):90-100,11.基金项目
国家重点研发计划资助项目(2024YFB3714200) （2024YFB3714200）
国家自然科学基金资助项目(52173305,52233017,52203384,U244120568) （52173305,52233017,52203384,U244120568）
中国科学院重点部署项目资助(RCJJ-145-24-40) （RCJJ-145-24-40）
