Surface nanocrystallization induced by fast multiple rotation rolling on 45 steel and its effect on microstructure and properties

摘要

In this paper, a nanocrystalline surface has been successfully induced on NO.45 steel plates by fast multiple rotation rolling. XRD and TEM, micro-hardness measurement has been carried out to investigate the change in micro-structure and physical properties. It also covers research done on the effect of treatment time on the grain refinement. The results shows that 60min duration has a relatively better refining effect: size of surface grain reduces to 37.4nm, smaller than that 47.6nm of samples treated for 30min. The effected thickness is about 90μm, and the topmost micro-hardness can be 458HV, improved by approximately 91% than as-receive sample. Sample treated for 30min has a 55μm thickness affected layer; the highest hardness value is 395HV.