激光熔覆Ni基合金/碳化物涂层组织及冲刷腐蚀磨损性能

在2Cr13马氏体不锈钢基材上激光多道搭接熔覆Ni—Cr3C2和Ni—WC复合涂层，考察两种激光熔覆层的微观组织、显微硬度对冲刷腐蚀磨损性能的影响，并与不锈钢基材对比。试验结果表明，两种涂层具有不同的凝固组织特征。含有未完全溶解WC硬质相的Ni—WC涂层比Cr3C2硬质相完全溶解的Ni—Cr3C2双相涂层的显微硬度高出约300HV，两种激光涂层的冲刷腐蚀磨损速率分别比不锈钢基材降低30％和60％。冲刷腐蚀磨损抗力的提高与熔覆层的组织状态、碳化物种类和数量以及涂层的韧化性能等因素密切相关。

Microstructure and Erosive-corrosive Wear Characteristics of Laser Cladding Stainless Steel with Ni-Cr3C2 and Ni-WC

The effects of microstructure and microhardness on erosive-corrosive wear (ECW) performance of a laser cladding NiCr 3C 2 and NiWC composite coatings with overlapping tracks on a martensitic stainless steel with 0.2 percent carbon was investigated and compared with the stainless steel substrate. The test results show that two coatings have different solidification structures. The microhardness of NiWC coating contained WC particles of incomplete dissol ution is about 300 HV higher than that of NiCr 3C 2 coating of biphase s tructure in which the hard phase was completely dissolved. The ECW rates of Ni Cr 3C 2 and NiWC decreased by approximately 60% and 30% respectively compared with that of the stainless steel substrate. The increase of ECW resistance is closely related to the structure feature of the cladding coatings, types and amounts of carbide, and the toughened ability of the coatings.