D38MSV5S非调质钢曲轴断裂分析及改进  

Fracture Analysis and Improvement of D38MSV5S Non-quenched and Tempered Steel Crankshaft

作　　者：柯豪 胡沛锋 饶晓晓[1] 赵红利[1] 蒋森 彭永键 吴雪龙 胡一恒 KE Hao;HU Peifeng;RAO Xiaoxiao;ZHAO Hongli;JIANG Sen;PENG Yongjian;WU Xuelong;HU Yiheng(Hubei University of Automotive Technology,Shiyan 442002,China)

机构地区：[1]湖北汽车工业学院,湖北十堰442002

出　　处：《金属材料与冶金工程》2024年第3期3-8,共6页Metal Materials and Metallurgy Engineering

基　　金：2023年湖北汽车工业学院大学生创新创业训练计划项目(DC2023011、202310525011);湖北省教育厅科技研发项目(Q20201802);湖北省教育厅项目(B2013081)。

摘　　要：某汽车用D38MSV5S非调质钢曲轴在行车过程中发生断裂,通过对失效曲轴的宏微观断口、化学成分、金相组织、显微硬度等检测分析。结果表明:曲轴基体组织粗大、A类夹杂物分布不均、材料偏析严重、裂纹源区条状硫化物较多等缺陷,导致曲轴早期疲劳断裂。通过改善锻造工艺、细化晶粒、控制硫化物形态以及优化改进曲轴的圆角滚压强化工艺,采用适当的滚压力和滚压圈数等参数,获得理想的残余压应力状态;优化滚压加工质量和加工效率,才能有效体现曲轴的轴颈感应淬火强化方式+圆角滚压复合强化效果,提高曲轴抗疲劳断裂能力,有效延长曲轴寿命。The D38MSV5S non quenched and tempered steel crankshaft of a certain automobile fractured during driving.The macroscopic and microscopic fracture surface,chemical composition,metallographic structure,microhardness,etc.of the failed crankshaft were detected and analyzed.The results indicate that the matrix structure of the crankshaft is coarse,the distribution of A-type inclusions is uneven,the material segregation is severe,and there are many strip like sulfides in the crack source area,which lead to early fatigue fracture of the crankshaft.By improving the forging process,refining grain size,controlling sulfide morphology,optimizing the fillet rolling strengthening process of the crankshaft and adopting appropriate rolling pressure and number of rolling cycles ideal residual compressive stress state is achieved;Optimizing the quality and efficiency of rolling processing is necessary to effectively reflect the composite strengthening effect of induction quenching and fillet rolling on the crankshaft neck,improve the fatigue fracture resistance of the crankshaft,and effectively extend its lifespan.

关 键 词：发动机曲轴 非调质钢 疲劳断裂 失效分析 圆角滚压 

分 类 号：TG142.1[一般工业技术—材料科学与工程]