回火工艺对HT9钢组织和力学性能的影响
Effect of tempering process on microstructure and properties of HT9 steel
谢谱 1赵吉庆 2颜廷亭3
作者信息
- 1. 昆明理工大学材料科学与工程学院,云南昆明 650093;钢铁研究总院有限公司特殊钢研究院,北京 100081
- 2. 钢铁研究总院有限公司特殊钢研究院,北京 100081
- 3. 昆明理工大学材料科学与工程学院,云南昆明 650093
- 折叠
摘要
利用SEM、TEM、相分析和拉伸、冲击试验,研究了不同回火工艺对HT9钢组织演变及力学性能的影响.结果表明,回火工艺通过影响析出相和位错来改变钢的力学性能;HT9钢在回火后的基体组织为板条马氏体,强化相为M23C6碳化物,未观察到其他析出相.随着回火温度升高,基体组织发生回复,位错缠结逐渐规整、减薄为位错网络,形成亚晶,M23C6碳化物发生Ostwald熟化,析出强化和位错强化作用减弱,强度和硬度降低,韧性上升;在770 ℃回火1～12 h,随着回火时间延长,基体组织回复,M23C6相发生熟化,强度和硬度逐渐降低并伴有一定的时间依赖性.结合力学性能标准,热处理制度为1040℃淬火1 h+770 ℃回火6 h时,HT9钢的强韧性匹配较好.
Abstract
Effect of tempering process on microstructure evolution and mechanical properties of HT9 steel was studied by SEM,TEM,phase analysis,tensile and impact tests.The results show that the tempering process can affect the mechanical properties of the tested steel by influencing the precipitates and dislocations.After tempering,the microstructure of the HT9 steel is lath martensite,and the precipitated phase is M23 C6 carbide,and no other precipitated phase is observed.With the increase of tempering temperature,the matrix gradually recovers,the dislocation tangles are gradually normalized and thinned into dislocation networks,and forming subgrains.The M23C6 carbide undergoes Ostwald ripening,the precipitation strengthening and dislocation strengthening effects are weakened,the strength and hardness decrease,while the toughness increases.Tempered at 770 ℃ for 1-12 h,as the tempering time prolongs,the matrix gradually recovers and the M23C6 phase gradually ripens.The strength and hardness gradually decrease with a certain time dependence.According to the mechanical properties standards,the strength and toughness match well when the heat treatment system of the HT9 steel is quenching at 1040℃for 1 h and tempering at 770℃for 6 h.
关键词
HT9钢/M23/C6相/组织/力学性能/热处理工艺/位错Key words
HT9 steel/M23C6 phase/microstructure/mechanical properties/heat treatment process/dislocation引用本文复制引用
出版年
2024
NETL
NSTL
万方数据