摘要
文章对75 kg/m在线热处理态贝氏体钢轨,在实验室进行了系列高温回火试验,并对不同回火工艺下钢轨的常规力学性能、-20℃断裂韧性、疲劳裂纹扩展速率、残余应力、显微组织进行了对比分析。试验结果表明,在线热处理态钢轨随着回火温度的升高,强度、硬度、残余应力呈线性降低;-20℃断裂韧性、冲击功等韧性指标先降低后升高,断裂韧性及疲劳裂纹扩展速率性能指标优于低温回火状态。在线热处理态钢轨高温回火处理,具有较高的断裂韧性和较低的疲劳裂纹扩展速率,可进一步发挥贝氏体钢轨高韧性特点和抗裂纹萌生扩展能力。
In this article,it is introduced a series of high temperature tempering tests for 75 kg/m on-line as-heat-treated bainite rails in the laboratory as well as compared and analyzed the conventional mechanical properties,fracture toughness at-20℃,spreading rate of fatigue crack,residual stress and microstructure of rails with different tempering processes.The test results show that the strength,hardness and residual stress of on-line as-heat-treated rails decrease linearly;such toughness indexes as fracture toughness at-20℃and impact energy firstly decrease and then increase with the tempering temperature increases as well as the performance indexes of fracture toughness and spreading rate of fatigue crack are better than those at low temperature tempering state.The on-line as-heat-treated with high temperature tempering is with higher fracture toughness and lower spreading rate of fatigue crack so that the characteristics of high toughness and resistance to generation and spread of crack for bainite rails could be further exerted.
作者
张凤明
梁正伟
何建中
李智丽
王嘉伟
杨静
Zhang Feng-ming;Liang Zheng-wei;He Jian-zhong;Li Zhi-li;Wang Jia-wei;Yang Jing(Technical Center of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,Inner Mongolia Autonomous Region,China)
出处
《包钢科技》
2021年第5期68-71,95,共5页
Science & Technology of Baotou Steel
关键词
贝氏体钢轨
高温回火
力学性能
显微组织
bainite rail
high temperature tempering
mechanical properties
microstructure
