【摘要】 为了高速列车车轴制造的国产化,试验研究25CrMo钢高速车轴坯机械性能的影响因素。结果表明:25CrMo钢高速车轴坯的成分和洁净度应符合EN 13261—2009标准对EA4T钢的要求,且合金元素含量偏中上线较好;轴坯要保证具有足够的锻造比;经适当的正火、淬火和回火热处理工艺,可保证得到的轴坯常规力学性能和疲劳性能满足车速200~250km·h-1高速列车车轴的要求,且具有优异的缺口疲劳性能,经热处理工艺获得的材料最优疲劳缺口敏感系数为0.16,远低于EN 13261—2009标准最大的允许值0.63;当25CrMo钢成品轴坯的晶粒尺寸控制在8级以上、且在轴坯最大直径1/2半径处的组织为贝氏体和回火马氏体复相组织时,其具有最佳性能。更多还原

【Abstract】 In order to localize the manufacture of high speed train axle,the influencing factors on the mechanical properties of 25 CrMo steel axle billet were experimentally studied.The results show that the composition and cleanliness of 25 CrMo steel billet should meet the requirements of EN 13261—2009standard for EA4 Tsteel and the percentage of alloy elements should be in higher or medium level.Enough forging ratio of axle billet is necessary.A further appropriate heat treatment process with normalizing,quenching and tempering can ensure that the conventional mechanical properties and fatigue properties of the obtained axle billet satisfy the requirement for high speed train axle at the speed of 200~250km·h-1.The excellent notch fatigue performance is achieved,and the optimal fatigue notch sensitivity coefficient for the sample through the best heat treatment process is 0.16,which is far lower than the maximum allowable value 0.63 in EN 13261—2009standard.When the grain size of the finished 25 CrMo steel axle billet is controlled at level 8or above,and the microstructure at 1/2radius of the largest diameter of the axle billet is bainite and tempered martensite(dual phase),the optimal mechanical properties are obtained.更多还原