以蔗糖为前驱体制备反应等离子熔覆高铬铁基复合涂层

High-chromium iron-base composite coating prepared by reactive plasma cladding using asphalt as carbonaceous precursor

以铁、铬、钨、镍粉末和碳的前驱体(蔗糖)为原料通过碳化制备了反应等离子熔覆Fe-Cr-C-W-Ni复合粉末,采用同步送粉反应等离子熔覆设备和优化的反应等离子熔覆工艺,在调质C蕉钢(C≤0.35%)基材表面制备了高铬铁基复合涂层。结果表明,采用前驱体碳化复合技术制备的Fe-Cr-C-W-Ni复合粉末粒度均匀、无有害相生成;熔覆所得到的涂层以(Cr,Fe)7C3/γ共晶为基体,其上分布大量的(Cr,Fe)7C3初生相。涂层与基材界面为完全冶金结合。涂层断面上的平均显微硬度约为1100HV。相同条件下所获涂层的磨损体积大约是常规等离子熔覆Ni60涂层的1/7。

A kind of Fe-Cr-C-W-Ni composite powders for reactive plasma cladding was prepared using iron, chromium, wolframium, nickel and sucrose (to pyrolyze the sucrose as carbonaceous precursor) as raw materials. High-chromium iron-base composite coatings were synthesized on the hardened and tempered C grade steel by reactive plasma cladding. Results show that the particle of Fe-Cr-C-W-Ni composites powder for cladding is uniform without any impurity. The high-chromium iron-base composite coating by reactive plasma cladding consists of a lot of the primary reinforced phase of (Cr,Fe)7C3 which distributes on the matrix of eutectic (Cr,Fe)7C3/γ. The coating has a metallurgical bonding with hardened and the substrate of tempered C grade steel. The average microhardness of the coating is about 1 100 HV. Under the same condition of wear test, the wear volume of the high-chromium iron-base composite coating is one seventh of that of the Ni60 coating by reactive plasma cladding.