激光熔覆Ni-Cr3C2涂层的微观组织及磨损性能

2Crl3马氏体不锈钢表面激光熔覆Ni-Cr8C2复合涂层的显微硬度随Cr3C2粒子添加量的增加而增加；激光熔池中Cr3C2粒子的部分溶解使得Cr、C元素向Ni基体中富集，导致激光熔覆层凝固组织中形成了较多的Cr7C3，M28(C，B)6和CrB化合物，比激光熔覆Ni单一涂层具有较高的干滑动摩擦磨损抗力。Cr3C2粒子的部分溶解使凝固组织中产生了较多的碳一铬和硼一铬硬质化合物所导致的熔覆层成分变化被认为是改善激光熔覆层干滑动磨损抗力的主要因素。

Microstructure and Dry Slide Wear Performance of Laser-clad Ni- Cr3C2 Composite Coating

Microhardness of laser-clad NiCr_3C_2 composite coating on 0.2%C martensitic stainless steel increased with the amounts of added carbide increasing in the considered range. The partial dissolution of Cr_3C_2 particles in the melted pool led to carbon and chromium enrichment in the matrix, and hence caused the formation of much Cr_7C_3, M_ 23 (C,B)_6 and more CrB in the solidifying structures. A higher wear resistance than a single Nialloy coating was achieved in the NiCr_3C_2 composite coating under the condition of dry sliding wear, which was closely related to composition changes caused by forming harder chromium-containing carbides or borides in the Ni alloy matrix resulting from dissolution of Cr_3C_2 particles.