Corrosion Fatigue Crack Analysis of Guide Gear Covers
The material of guide gear cover was made of 42CrMo medium carbon quenched and tempered steel,and the parts were galvanized and heat-treated for surface protection.The corrosion fatigue crack occurred during the service of the part in the marine climate environment,and the crack was located at the edge where the side intersected with the upper sur-face,where the exposed surface of the guide tooth cover was located,and there were corrosion pits and other obvious corro-sion characteristics in the crack source area.The cracks of the guide gear cover were detected and analyzed by means of mac-ro and micro morphology analysis,energy spectrum analysis,chemical composition detection,metallographic structure anal-ysis and mechanical property analysis,and it was concluded that the existence of corrosive elements such as S and Cl in the service environment of the guide gear cover caused corrosion to the exposed surface of the parts,and the corrosion fatigue occurred under the alternating load during the use of the guide gear cover,which exceeded the corrosion fatigue limit of the material,and the fatigue crack of the guide tooth cover continued to expand and then the guide tooth cover failed.
NETL
NSTL
万方数据
