Research On Fracture Failure Analysis Of The Outer Race Of Drive Shaft

In this paper,failure analysis procedure chart have been used,which start from raw materials,machining process and stress analysis,develop appropriate measures for improvement on delayed fracture of transmission shaft and achieve good results.By macroscopic and microscopic fracture analysis,determine the nature of the wheel fracture is delayed brittle fracture.Improper selection of raw materials,large residual stress during the heat treatment and instability of assembly technology result in delayed brittle cracking.For the above reasons,proposed the following improvements:(1)increasing raw material's grades,choosing the better quality steel to improve the anti-delayed cracking properties(2)optime the temper after induction heat-treatment,tempering it adequately,reduce residual stress after heat treatment(3)improving the assembly process on large nut:(1)Change anti-rust oil of the friction pair,use water-based anti-rust oil to replace crude anti-rust oil,reducing the friction coefficient;(2)improve the tightening process,the origin torque method modified to the torque angle method,to reduce the coefficient of friction's impact on the clamping force.By implementing these measures,it has not found another drive shaft failure with these patterns.