Evolution of Microstructure and Mechanical Properties of 20Cr13 Under Cavitation Erosion

Evolution of microstructure and mechanical properties of 20Cr13 was studied. Evolution of microstructure was researched by using optical, scanning electron, 3D measuring laser microscope to describe the changes. To explore cavitation erosion process as a fatigue damage, residual stress, micro hardness and roughness were measured by X-ray diffraction analysis, Vickers micro hardness tester and roughness tester respectively. The results showed that micro hardness and residual stress increased for deformation in the early period of cavitation erosion, then decreased gradually because of spalling. Microstructure got increasingly long strips and large holes which turned into cracks. And roughness kept growing with time increasing. The cavitation resistance of 20Cr13 has been decreasing during the 240 min of cavitation erosion, which may be related to the decreasing of micro hardness and the increasing of roughness and residual stress. And that cavitation erosion process was seen as a fatigue damage seems reasonable from damage evolution of depth in microstructure and residual stress.