【摘要】 为了提高高速货运列车转向架弹簧的耐疲劳性能,对两个炉号的棒状60Si2CrVAT弹簧钢用相同工艺热处理后,在MTS880材料试验机上进行了三点弯曲疲劳寿命对比试验,实验载荷采用阶梯式增加法;用扫描电镜对弹簧钢的疲劳断口和基体组织进行观察。疲劳实验结果表明,不同炉号的弹簧钢疲劳寿命相差很大。组织分析表明,疲劳寿命较低的弹簧钢中,淬火加热前存在颗粒状碳化物,奥氏体化时未溶入奥氏体而残留在淬火组织中,并在局部聚集,导致疲劳寿命降低。更多还原

【Abstract】 In order to meet the ever increasing requirement of high fatigue resistant spring used in the bogie of high speed freight train,the three-point bend fatigue property was experimentally studied of two batches of rod 60Si2CrVAT spring steel underwent same heat treatment process by MTS 880 materials tester.A step increment in fatigue load was adopted in the test.The fatigue fracture and microstructure of the matrix of the spring steel were studied by SEM.The fatigue tests showed that the fatigue life of 60Si2CrVAT spring steel from different batch number varied considerably.Microstructural analysis indicated that granular carbides existed in the steel of lower fatigue life prior to quenching heating, which remained undissolved during austenizing and remained in the quenching microstructure,resulting in lower fatigue life.更多还原