表面滚压强化A473M钢的组织及性能

为了提高A473M马氏体不锈钢表面的耐磨性能,采用滚压加工强化不锈钢表面,对其组织及性能进行研究,并确定了最佳工艺参数.采用扫描电子显微镜、白光干涉仪、显微硬度计和摩擦磨损实验机对不锈钢的硬化层组织、表面粗糙度、显微硬度及摩擦磨损性能进行表征.结果表明,当滚压进给量由0.05 mm/r增加至0.15 mm/r时,不锈钢表面粗糙度变化趋势呈“∨”形,表面显微硬度和磨损性能的变化趋势呈“∧”形.当进给量为0.1 mm/r且表面粗糙度为62.7 nm时,不锈钢硬化层组织明显细化,滚压层表面显微硬度达到550 HV且为基材的2.2倍,硬化层深度达到200 μm,相对耐磨性为3.7.

Microstructures and properties of surface rolling strengthened A473M steel

In order to improve the surface wear resistance of A473M martensitic stainless steel, the rolling-machining was conducted on the surface of stainless steel, its microstructures and properties were studied, and the optimal process parameters were determined. The microstructures in the hardened layer, surface roughness, microhardness as well as the friction and wear properties of stainless steel were characterized with scanning electron microscope, white-light interferometer, microhardness tester and friction-wear tester. The results show that when the feeding rate increases from 0.05 mm/r to 0.15 mm/r, the variation tendency of surface roughness of stainless steel is similar to a “∨” shape, while the variation tendency of surface microhardness and wear properties exhibits a “∧” shape. Under the optimal process parameters, i.e.the feeding rate at 0.1 mm/r and the surface roughness of 62.7 nm, the microstructures in the hardened layer of stainless steel get significantly refined. The surface microhardness of rolling layer is 550 HV, which is 2.2 times higher than that of substrate. Furthermore, the depth of hardened layer reaches 200 μm, and the relative wear resistance is 3.7.