摘要
为提高17-4PH不锈钢的耐水蚀性能,利用激光熔覆方法在其表面制备了Stelite6合金涂层。研究了涂层的微观组织形貌、相组成以及元素扩散行为,分析了涂层的硬度分布和耐水蚀性能。结果表明,Stellite6涂层微观组织由平面晶、胞状和柱状晶、树枝晶以及等轴晶组成,物相组成包括面心立方(FCC)结构的γ-Co固溶体和M_(23)C_6、Cr_7C_3、CoC_x等,Fe、Co元素在基体和涂层间的扩散明显。Stellite6涂层的最高硬度为561HV,平均硬度约为基材的1.4倍。多道多层熔覆时,搭接区存在软化现象,横向硬度分布出现周期性波动。在压力为80 Mpa、温度为80℃、水流冲蚀时间为30h的条件下,基材表面发生了严重的材料破坏,而Stellite6涂层表面基本保留了初始形貌,涂层的耐水蚀性能相比基材的有了显著提高。
In order to improve the water erosion resistance property of the 17-4PH stainless steel, Stellite6 alloy coating is prepared on the surface of 17-4PH stainless steel by laser cladding. The coating microstrueture, phase composition and element diffusion are studied and the hardness distribution and water erosion resistance property of the coating are analyzed. The results show that the microstructure of the Stellite6 coating is composed of plane crystal, cellular and columnar crystal, dendrite, and equiaxed crystal. The phase consists of 7-Co solid solution with face centered cubic (FCC) structure, M23C6, Cr7 C3, and CoCx. Fe and Co elements diffuse between the substrate and the coating layer obviously. The highest hardness of the Stellite6 coating is 561 HV, and its average hardness is about 1.4 times of that of the substrate. In the multi-channel and multi-layer cladding, softening phenomenon occurs in the overlapped regions and the transverse hardness of Stellite6 coating fluctuates periodically. Under the conditions of pressure being 80 Mpa, temperature being 80 ℃ and water erosion time being 30 h, the substrate surface is destroyed seriously. However, the Stellite6 coating surface basically retains the original appearance. It indicates that the water erosion resistance property of the coating has been significantly improved than that of the substrate.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2017年第4期101-108,共8页
Chinese Journal of Lasers
基金
上海市教育委员会"曙光计划"(12SG15)