喷丸对4Cr5Mo2V钢高温摩擦磨损性能的影响
Effect of Shot Peening on High Temperature Friction and Wear Properties of 4Cr5Mo2V Steel
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摘要: 对4Cr5Mo2V钢试样进行3道次复合喷丸,通过与未喷丸试样对比,研究了喷丸对试验钢表面形貌、显微组织、硬度、残余应力以及高温(100,300,500 ℃)摩擦磨损性能和机制的影响。结果表明:喷丸处理显著提高了试验钢表面粗糙度,使试验钢表面形成了明显的塑性变形层、硬化层与残余压应力层;在100,300,500 ℃下,与喷丸前相比,喷丸后试验钢的磨损率分别降低了41.8%,17.1%,63.3%,耐磨性能的提高与喷丸产生的硬化层和残余压应力层有关。在100,300 ℃下,喷丸前后试验钢的磨损机制均主要为黏着磨损和磨粒磨损,而当温度升高至500 ℃时,磨损机制为氧化磨损,喷丸试验钢仍能保持较高的硬度与残余压应力,同时表面氧化层更致密稳定,仅发生轻微氧化磨损。Abstract: 4Cr5Mo2V steel specimens were processed by three-pass complex shot peening. The effects of shot peening on the surface morphology, microstructure, hardness, residual stress, and high temperature (100, 300, 500 ℃) friction and wear properties and mechanism of the test steel were studied by comparing with those of un-shot peened specimens. The results show that the shot peening significantly improved the surface roughness of the test steel, and induced an obvious plastic deformation layer, a hardened layer and a residual compressive stress layer on the surface. The wear rate of the test steel after shot peening was reduced by 41.8%, 17.1% and 63.3% at 100, 300, 500 ℃, compared with that before shot peening, respectively. The improvement of wear resistance of shot peened test steel was related with the hardened layer and residual compressive stress layer produced by shot peening. At 100 ℃ and 300 ℃, the wear mechanism of the test steel before and after shot peening was mainly adhesive wear and abrasive wear. When the temperature rised to 500 ℃, the wear machanism was oxidation wear; the shot peened test steel could still maintain high hardness and residual compressive stress, and the surface oxide layer was more dense and stable, therefone only slight oxidative wear occurred.