高频微锻造处理对304不锈钢表面激光熔覆层的影响(英文)

Effects of High-frequency Microforging on the Laser Cladding Layer Prepared on the 304 Stainless Steel Substrate

对304不锈钢基材表面制备的激光熔覆层进行了高频微锻造处理。通过光学显微镜和X射线衍射仪分别研究了高频微锻造处理前后激光熔覆层的显微组织和相组成,利用显微维氏硬度计和电化学工作站分别对其进行了显微硬度测试和耐腐蚀性能测试。结果表明:经过高频微锻造处理后,激光熔覆层中的枝晶组织得到破碎,晶粒变细,但相组成无明显变化;微锻造作用区的显微硬度明显提高,影响深度为0.65 mm,表层硬度提高了约30%,高频微锻造处理对激光熔覆层的硬度影响程度随着距表层距离的增加而下降;激光熔覆层的耐腐蚀性能经微锻造处理后得到改善,为原始的2倍。

The laser cladding layer on the 304 stainless steel surface is modified by a high-frequency microforging process. The microstructure and phase constitution of the laser cladding layer before and after the high-frequency microforging treatment are characterized by using optical microscopy and X-ray diffraction. The microhardness distribution and corrosion property of the counterparts are examined by Vickers microhardness tester and the electrochemical work station, respectively. The results show that laser cladding layer is of a broken dendritic microstructure and refined grain size after microforging, while there is no obvious change in the phase constitution.The microhardness of the microforged area is greatly enhanced with an affected depth of 0.65 mm. The average microhardness of the surface is improved by about 30% and the microhardness increment decreases gradually with the increasing distance from the top of the cladding layer. The corrosion resistance of the laser cladding layer is improved by nearly two folds after microforging.