高速列车车轴DZ2钢的强韧性关系和低温脆性  

Investigations on Strength-Toughness Relationship and Low Temperature Brittleness of High-speed Railway Axle Steel DZ2

作　　者：刘硕 张鹏[1,2] 王斌[1,2] 汪开忠[3] 许自宽[1] 胡芳忠[3] 段启强 张哲峰[1,2] LIU Shuo;ZHANG Peng;WANG Bin;WANG Kaizhong;XU Zikuan;HU Fangzhong;DUAN Qiqiang;ZHANG Zhefeng(Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;Technology Center,Maanshan Iron and Steel Co.,Ltd.,Maanshan 243000,China)

机构地区：[1]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016 [3]马鞍山钢铁股份有限公司技术中心,马鞍山243000

出　　处：《材料研究学报》2024年第8期561-568,共8页Chinese Journal of Materials Research

基　　金：国家重点研发计划(2022YFB3705203)。

摘　　要：调控高速列车车轴DZ2钢的回火温度,对其进行拉伸实验和常、低温冲击试验并观察和分析其微观组织的,研究了这种钢的强韧性关系和低温脆性。结果表明:随着回火温度从430℃提高到700℃,DZ2钢的抗拉强度从1357 MPa降低到761 MPa,断后延伸率从11.7%提高到28.4%,室温冲击功从34.3 J提高到98.7 J,低温冲击功从24 J提高到90.3 J。这表明,回火温度降低对其冲击功的影响逐渐减弱,低温冲击功下降最低只有8%,其原因是碳化物的球化改变了微观变形行为。在满足室温力学性能标准的情况下,调整回火温度可改善这种钢的低温冲击韧性。Impact toughness and its low-temperature transformation are key indicators of high-speed railway axle materials,which are closely related to the microstructure of the material.The embrittlement degree of materials with different microstructures at low temperatures also varies.Aiming to find a way to optmize the strength-toughness relationship of the relevant steel,the effect of adjusting the tempering temperature on the strength-toughness relationship of DZ2 steel,which was newly designed and developed at home for high-speed railway axle,was studied via tensile tests,room-and low-temperature impact tests,as well as observation and analysis of the microstructure evolution of the steel.Then the performance changes of the steel during the tempering treatment process were explained.The results indicate that as the tempering temperature increases,the tensile strength gradually decreases from 1357 MPa to 761 MPa,the elongation after fracture increases from 11.7%to 28.4%,the room temperature impact energy gradually increases from 34.3 J to 98.7 J,and the low temperature impact energy gradually increases from 24 J to 90.3 J.However,the impact of temperature reduction on the impact energy gradually weakens,the minimum impact energy decrease percentage of low-temperature is 8%.The transformation trend of these properties is closely related to the micro-scale deformation mechanism changes caused by the gradual spheroidization of carbides.It can be concluded from the comprehensive analysis that,while meeting the requirements of room temperature mechanical performance standards,adjusting the tempering temperature can improve the low-temperature impact toughness of the axle steel,to meet the needs of further high-speed railway speed increase and safe operation in harsh environments.

关 键 词：金属材料 车轴钢DZ2钢 回火热处理 抗拉强度 冲击功 低温脆性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]