钢板弹簧断裂失效行为研究

目的研究汽车钢板弹簧断裂失效的原因。方法通过化学成分分析、硬度测试、断口形貌分析、金相组织分析等手段研究汽车钢板弹簧的失效行为。结果由于表面脱碳层过深,使得表面疲劳强度及耐蚀性降低,同时因长时间腐蚀作用在表面产生腐蚀坑及腐蚀裂纹,并且在循环外力作用下,腐蚀缺陷处产生应力集中,早期裂纹萌生于表面腐蚀缺陷处并扩展,最终导致腐蚀疲劳断裂。结论通过控制热处理条件、增加加工余量并去除脱碳层、表面喷丸处理等措施,钢板弹簧表面耐蚀及抗疲劳性能大幅提高,可有效避免脱碳引起的腐蚀疲劳断裂。

Rupture Failure Behavior of Leaf Spring

Objective To research causes for failure of leaf spring. Methods The failure behavior of leaf spring was analyzed through chemical component test, fracture morphology analysis, microstructure analysis, etc. Results The fatigue strength and corrosion resistance of the leaf spring declined due to deep surface decarburization. Meanwhile, corrosive conditions lead to the corrosion defects on the surface. Under action of cyclic force, early crack appeared and extended in corrosion defects on the surface, resulting in corrosion fatigue fracture. Conclusion Methods such as adjusting the temperature of thermal treatment, increasing machining allowance, removing decarburized layer, shot peening treatment on surface, etc. could improve the corrosion resistance and anti-fatigue performance on surface of leaf spring and effectively avoid corrosion fatigue fracture of the leaf spring.