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通过增压喷丸方式使45#钢实现表面纳米化,采用MMU-5G高温材料端面磨损试验机进行45#钢纳米晶层摩擦磨损性能随温度变化的试验,利用TEM表征喷丸后表层的组织,DSC与显微硬度研究纳米层的热稳定性,XPS和SEM表征磨损表面的成分及形貌.结果发现:当温度低于200℃时,喷丸样品表面硬度高,有效减少实际接触面积,耐磨性能优于未喷丸样品;在200～400℃之间时,纳米化样品表层组织结构中存在大量的晶界、位错、空位等缺陷为氧原子与金属原子提供更多的扩散通道,加速疏松的Fe2O3氧化物的形成与脱落,耐磨性能低于未喷丸样品;在400～550℃之间时,喷丸样品由于回复与再结晶,与未喷丸的耐磨性能基本一致.
The 45 # steel was nano-sized by means of pressurized shot peening. The friction and wear properties of 45 # steel nanocrystalline layer with temperature were tested by MMU-5G high temperature endface wear tester. The microstructure of the surface layer after shot peening , DSC and microhardness were used to study the thermal stability of the nanostructures.XPS and SEM were used to characterize the composition and morphology of the worn surfaces.The results showed that the surface hardness of shot peening samples was high and the actual contact area was effectively reduced when the temperature was below 200 ℃, At 200 ~ 400 ℃, there are a large number of grain boundaries in the microstructure of nano-scale samples. The defects such as dislocations and vacancies provide more diffusion channels for oxygen atoms and metal atoms , Accelerating the formation and shedding of loose Fe2O3 oxide, and the wear resistance is lower than that of non-shot peening samples. When the shot peening sample is between 400 and 550 ℃, the shot peening samples are basically the same as the non-shot peening due to the recovery and recrystallization .