核电设备用钴基合金耐磨层多工艺熔敷性能比较分析

Comparison and analysis of Co-based alloy wear-resistant coatings deposited by multiple technologies in nuclear power plant

为表征氧乙炔焊、激光熔敷钴基Stellite 6合金耐磨层组织性能的差异,采用成熟的焊接工艺参数完成激光熔敷及氧乙炔焊接Stellite 6合金耐磨层制备。基于耐磨层试板,通过试验研究不同工艺对Stellite 6合金涂层成分、硬度、组织及腐蚀性能的影响。研究发现,针对氧乙炔焊、激光熔敷工艺,Stellite 6合金涂层硬度平均值均满足验收要求,金相试验未发现异常组织。EDS能谱分析发现,氧乙炔焊接工艺条件下耐磨层成分偏析明显,尤其是C、W等硬质颗粒形成元素。特定工况下,电化学腐蚀试验显示,激光熔敷条件下耐磨层钝化效应更加明显。

In order to characterize the difference of microstructure and properties between oxyacetylene welding and laser cladding of cobalt-based Stellite 6 alloy wear-resistant layer,mature welding parameters are adopted to prepare wear-resistant layer of test plate. The effects of different technologies on the composition,hardness,microstructure and corrosion performance of Stellite 6 alloy coating are studied based on the test plate with wear resistant layer. The results show that for oxyacetylene welding and laser cladding technology,the hardness average value of Stellite 6 alloy coating can meet the acceptance requirements by using mature welding parameters,and no abnormal microstructure is found in metallographic test. By EDS energy spectrum analysis, it is found that the composition segregation of wear-resistant layer is obvious under the condition of oxyacetylene welding technology,especially the formation elements of hard particles such as C,W and so on. Under specific working condition,the electrochemical corrosion test shows that the passivation effect of wearresistant layer is more obvious under the condition of laser cladding.