Failure Analysis of 35CrMo Shaft Driving Pump

Means of macro-analysis,mechanical property test,metallographic analysis and stress analysis were employed to analyze the cracking reason of 35CrMo shaft driving pump which broke after 40 hours using.The results indicated that fatigue strength of the shaft reduced because of the improper heat treating,which led to the rotary bending fatigue fracture of the shaft during service process.