INFLUENCE OF RESIDUAL STRESS AND SURFACE MORPHOLOGY ON FATIGUE PROPERTIES OF 60Mn STEEL
残余应力和表面形态对60Mn疲劳性能的影响

Influence of residual stress and surface morphology, resulting from shot-peen- ing, on fatigue behaviour of medium temperature tempered spring steel 60Mn have been stu- died. The induced compressive residual stress in near-surface region may improve fatigue lim- it from 930 to 1010 MPa, and the very high tensile residual stress in the interior may reduce it from 1010 to 940 MPa, whereas the severe surface damage may cause a drop-off of it from 1010 down to 800 MPa. Fatigue cracks initiated in such position where the equivalent Mises stress, including residual stress, exceeded the local strength of the material. The compressive residual stress, induced by shot-peening, may intensify the effect of crack closure, so as to de- crease the crack growth rate.