连杆断裂失效分析及锻造折叠缺陷控制研究

Control Research on Connecting Rod Fracture Failure Analysis and Forging Folding Defects

目的确定连杆断裂失效模式、机理和原因,找到有效预防连杆锻造缺陷的措施。方法针对连杆断裂失效问题,在对连杆合格件和故障件进行符合性对比试验分析的基础上,对故障件进行断裂失效模式、机理和原因分析,并对连杆锻造折叠缺陷产生类型、机理、原因、条件和时段进行分析。结果只有在连杆制坯坯料形状与尺寸不合理、制坯坯料在预锻模膛中位置不合理、预锻形状与尺寸不合理、预锻成形打击力或变形速度不合理、终锻形状与尺寸不合理、锻模导向功能失效等多种极端不利因素同时存在的条件下,才具有产生复合型锻造折叠缺陷的可能性。结论通过连杆锻造过程控制和锻造首锻控制,可有效预防锻造折叠缺陷产生,满足锻件高优质性、高可靠性和高有效性要求。

The work aims to determine the mode,mechanism and reason of connecting rod fracture failure,and explore effective measures to prevent forging defects of connecting rods.For fracture failure of connecting rods,based on conformance comparison test and analysis between qualified parts and faulty parts,the failure mode,mechanism and cause of the faulty parts were analyzed.The types,mechanisms,causes,conditions and periods for forging folding defects of connecting rods were analyzed.It could provide a powerful solution for effective prevention of forging folding defects of connecting rods.The results showed that the folding defects of compound forging were possible only when there were multiple extreme adverse factors,such as unreasonable shape and size of the connecting rod blank,unreasonable placement of the blank in the preforging die chamber,unreasonable shape and size of the preforging,unreasonable strike force or deformation speed of the preforging forming,unreasonable shape and size of the finish forging,and guiding function failure of the forging die.By controlling the forging process and the first forging of the connecting rod,it can effectively prevent the occurrence of forging folding defects,meet the requirements of high quality,high reliability and high effectiveness of connecting rod forgings.