商用车钢板弹簧断裂原因分析

Fracture Analysis of Leaf Spring of Commercial Vehicle

在台架试验及恶劣工况可靠性试验过程中钢板弹簧经常发生早期断裂。本文从结构设计、服役环境、材料工艺等方面进行断裂原因分析。分析工作表明:中心孔倒角设计及其冲压成型工艺可延缓因U型螺栓松动引起中心孔处断裂;摩擦磨损导致多源疲劳断裂占据板簧断裂失效主要部分,亟需解决片间摩擦磨损问题;腐蚀环境和服役载荷综合作用易导致板簧平行段和卷耳处发生腐蚀疲劳断裂;脱碳层深、硬度不良、喷丸工艺不合理均会降低板簧的疲劳寿命。

This paper summarized the cause analysis of leaf spring failure in the process of bench test or bad road test,including three factors:structural factor,working conditions,materials and technology.Analysis work showed that the design of center-hole chamfer and its stamping process could delay the fracture of the center hole caused by the loosening of U-bolt.The multi-source fatigue fracture caused by friction and wear was the main reason for leaf spring fracture failure.So it was urgent to solve the problem of inter plate friction and wear.The combined action of corrosion environment and service load could easily lead to corrosion fatigue fracture at the parallel section and the rolling ear of leaf spring.Unreasonable depth of decarburization layer,hardness and shot peening process would reduce the fatigue life of leaf spring.This paper provides support for material technicians and product designers engaged in leaf spring research and development.