重型汽车钢板弹簧早期断裂原因  

Early Fracture Reason of Leaf Spring of Heavy Duty Truck

作　　者：蒋松蔚 马鸣图[1] 王建斌 冯毅[1] 龚煜 金学军[3] 张均萍 周佳[1] JIANG Songwei;MA Mingtu;WANG Jianbin;FENG Yi;GONG Yu;JIN Xuejun;ZHANG Junping;ZHOU Jia(China Automotive Engineering Research Institute Co.,Ltd.,Chongqing 401122,China;Shandong Beiqi Haihua Automobile Parts Co.,Ltd.,Zibo 255202,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]中国汽车工程研究院股份有限公司,重庆401122 [2]山东北汽海华汽车部件股份有限公司,淄博255202 [3]上海交通大学材料科学与工程学院,上海200240

出　　处：《机械工程材料》2020年第8期93-96,102,共5页Materials For Mechanical Engineering

基　　金：国家自然科学基金重点资助项目(U1764252)。

摘　　要：某重型汽车51CrMnVA钢板弹簧(板簧)预压后在冬天放置时发生断裂,通过断口分析、显微组织观察、力学性能测试、与正常服役后失效板簧进行对比等方法对其早期断裂原因进行了分析。结果表明:由于回火温度偏低,该板簧强度和硬度偏高,韧性偏低,加之钢中可扩散氢含量和预压变形应变速率过高,板簧在低温下发生脆性断裂;降低钢中可扩散氢含量,提高回火温度,延长回火时间,增加氢陷阱数量,得到适当的强韧性匹配,可有效避免板簧的早期失效和氢致延迟断裂。A 51CrMnVA leaf spring of heavy duty truck broke when placed in winter after being preloaded.The early fracture reasons were analyzed by fracture analysis,microstructure observation,mechanical performance testing,and comparison with the fractured leaf spring after normal service.The results show that the high strength and hardness and low toughness of the leat spring due to a relatively low tempering temperature,and high diffusible hydrogen content in steel and high tension rates during presetting caused the brittle fracture of the leaf spring at low temperatures.Reducing the diffusible hydrogen content in steel,increasing the tempering temperature,extending the tempering time,increasing the number of hydrogen traps,and achieving appropriate matching of strength and toughness could effectively avoid early failure and hydrogen-induced delayed fracture of the leaf spring.

关 键 词：钢板弹簧 脆性断裂 可扩散氢 强韧性 回火 

分 类 号：TG142.1[一般工业技术—材料科学与工程]