The effect of multifunction cavitation (MFC) processing on the fatigue properties of 
carburized low-alloy steel rods was examined under rotating bending. MFC was conducted for 
electrochemically polished steel rods pre-treated with gas carburizing and tempering. In 
contrast to conventional surface modification techniques that use a cavitation jet, MFC can 
generate compressive residual stress and suppress the formation of surface dents on the surface 
of carburized rods during rotation. High compressive residual stress (~800 MPa) was generated 
on the surface of carburized rods by MFC because of a martensitic transformation; however, 
MFC did not increase the fatigue limit of the carburized rods because the compressive residual 
stress generated by MFC was released during fatigue tests and the surface roughness value was 
slightly increased by MFC due to the formation of surface pits with red rust. By contrast, the 
compressive residual stress for the carburized specimens without MFC increased because of 
the stress induced martensitic transformation during fatigue tests, which is one of the reasons 
why the fatigue limit of the carburized rods subjected to MFC did not increase. The fatigue 
limit estimation based on a modified Goodman diagram and mechanism of subsurface fatigue 
fracture in carburized steel rods were also examined.