【作者】 宋明强； 李俊儒； 张朝磊； 陈列； 佐辉； 钱才让； 刘雅政；

【Author】 Song Mingqiang;Li Junru;Zhang Chaolei;Chen Lie;Zuo Hui;Qian Cairang;Liu Yazheng;School of Materials Science and Engineering; University of Science and Technology Beijing;Xining Special Steel Co., Ltd.;

【机构】 北京科技大学材料科学与工程学院； 西宁特殊钢股份有限公司；

【摘要】 通过正交实验和固溶实验,研究了热处理工艺对KT5331钢组织和低温冲击韧性的影响规律。实验结果表明,热处理态试验钢显微组织均为回火马氏体组织,断口机理为穿晶解理断裂。1040~1120℃淬火温度对低温冲击韧性影响较大,并且随淬火温度升高,低温冲击功先上升后下降。当淬火温度低于1080℃时,低温冲击值较低是由原始奥氏体晶粒出现明显晶粒异常长大现象导致,当淬火温度高于1080℃时,低温冲击值下降是由原始奥氏体晶粒长大导致。淬回火参数中回火温度是影响低温冲击韧性的主要参数,适当提高回火温度可有效改善低温冲击韧性。1080°C保温60 min以上淬火,720°C以上保温2 h回火可有效地提高KT5331钢的低温冲击性能。并且调质处理前1150°C固溶处理可小幅改善低温冲击性能。更多还原

【Abstract】 The influence of heat treatment on microstructure and mechanical property of KT5331 steel has been studied by orthogonal and solution experiments. The experimental results show that microstructure of heat treated is tempered martensite and the fracture is transgranular cleavage. quenching temperature has great impact on low-temperature impact at 1040~1120℃, and with the increase of quenching temperature, the low-temperature impact begins to rise then falls. When the quenching temperature is below 1080, the lower low-temperature impact was caused by abnormal grain growth of primary austenite. However, when the quenching temperature is above 1080, the lower low-temperature impact was caused by the increase of austenite grain size. The tempering temperature is the main parameter and the high tempering temperature increases the low-temperature impact. The best heat treatment process for low-temperature impact is that quenching at 1080 °C after holding for 1 hour, and tempering at 720 °C. And the low-temperature impact can be inproved by solution treatment before the quenching and tempering heat treatment.更多还原