Analysis of an Engine Front Baffle Fatigue Cracking

Front baffle cracking in low-cycle fatigue strength test was investigated. It is suggested that there was overheating running in the test by visual examination of baffle surface color and fracture surface color. It is obtained that the front baffle was cracked by fatigue mechanism by observation of fracture surface. It is confirmed that the temperature range of overheating was about 700~750°C by temperature and color test. It is shown that the value of hardness decreased heavily when temperature was above 700°C by hardness measurement of sample in temperature and color test, demonstrating the mechanical property decreased severely in the overheating temperature range. Finally, the root cause for the cracking of front baffle might be attributed to overheating running in the test.