商用车用变截面板弹簧疲劳断裂失效分析  

Fatigue Fracture Failure Analysis of Variable Cross-section Panel Springs for Commercial Vehicles

作　　者：谭亮 Tan Liang(Research&Development Institute,Jiangyin Xingcheng Special Steel Works Co.,Ltd.,Jiangyin Jiangsu 214400,China)

机构地区：[1]江阴兴澄特种钢铁有限公司研究院,江苏江阴214400

出　　处：《山西冶金》2023年第12期25-28,31,共5页Shanxi Metallurgy

摘　　要：疲劳断裂是钢板弹簧的主要断裂形式,随着变截面簧承受应力水平的提高和变截面簧承受交变应力的服役特点,使得变截面簧的疲劳性能对近表面及表面缺陷的敏感性显著增加。结合客户板弹簧的加工工艺流程,通过宏观分析、金相检验,断口电镜扫描以及能谱分析等测试手段,对失效断裂样品进行全面解剖分析。结果表明:板簧变截面部分经过两次加热产生较重脱碳层,并伴有全脱碳,降低了表面的疲劳强度;热处理采用水基淬火液淬火,组织应力大;板簧加工抛丸过程在表面产生凹坑缺陷,成为疲劳过程中的应力集中点。此些问题是导致钢板弹簧早期失效断裂的原因,后续通过对板簧生产加热工艺、淬火工艺及抛丸工艺进行优化,有效提升了板簧的疲劳寿命。Fatigue fracture is the main fracture form of leaf spring.With the increase of the stress level of the variable section spring and the service characteristics of the variable section spring under altermating stress,the fatigue performance of the variable section spring is significantly more sensitive to the surface defects near the surface area.In this paper,combined with the processing process of the customer's leaf spring,the failure fracture sample was comprehensively dissected and analyzed by means of macroscopic analysis,metallographic inspection,fracture electron microscopy scanning and energy spectrum analysis.The results show that a heavy decarburization layer is produced by heating the variable section of the leaf spring twice,accompanied by complete decarburization,which reduces the fatigue strength of the surface.The heat treatment is quenched by water-based quenching liquid,and the stress of the tissue is large.In the process of shot blasting,the surface of the plate spring is pitted,which becomes the stress concentration point in the fatigue process.The above problems are the causes of early failure and fracture of leaf springs.Subsequently,the heating process,quenching process and shot blasting process of leaf spring production were optimized,which effectively improved the fatigue life of leaf spring.

关 键 词：钢板弹簧 水基淬火液 全脱碳 抛丸 疲劳试验 失效分析 

分 类 号：TG142.1[一般工业技术—材料科学与工程]