多元合金加入对Fe65粉末等离子熔覆层组织和性能的影响

Effect of Multicomponent Alloy Addition on Microstructure and Properties of Fe65 Powder Plasma Cladding Layers

采用微束等离子熔覆方法,在H13钢基体上制备了以自熔性合金粉末Fe65为基础成分、添加适量Al、W、V的正交实验熔覆层,研究了熔覆层的显微组织、高温回火性能和高温氧化性能。结果表明,正交实验熔覆层的显微组织中,奥氏体晶粒细小,短针状FeAl和Fe3Al金属间化合物沿晶分布,Cr7C3、WC、VC等碳化物呈枝晶分布,马氏体消失;与熔覆层后的空冷相比,经700℃高温回火后,正交组熔覆层的硬度提高,8H（Fe65-12%Al-4%W-1%V）熔覆层的硬度增加显著,抗高温回火性能最优,而参照组Fe65粉末覆层硬度明显下降,H13钢硬度则较低。在700℃高温氧化试验中,加入适量Al的正交组熔覆层的抗高温氧化性能大大优于Fe65粉末覆层及H13钢,其中8H覆层的氧化增重仅分别为Fe65粉末覆层、H13钢的32%及8.5%,表现出优异的高温抗氧化性能。

The orthogonal experimental cladding layers, with the self-fluxing alloy powder Fe65 as the basic composition and the multicomponent alloy addition of proper Al, W, and V, were prepared on H13 steel substrate by micro plasma cladding method. The microstructure, high temperature tempering resistance and high temperature oxidation properties of the cladding layers were investigated. The results show that in the microstructure of the orthogonal experimental cladding layers,the austenite grains is fine, while the acicular FeAl and Fe3 Al intermetallic compounds distribute along the grain boundaries,and Cr7 C3, WC, VC and other carbides exists in the form of dendrites, and then the martensite disappears. Compared with the cladding layer after air cooling, after 700℃ high temperature tempering, the hardness of the orthogonal group cladding layers improves, the increase of the hardness of 8 H（Fe65-12% Al-4% W-1% V） cladding layer is the greatest, then, the high temperature tempering resistance is optimal and the decline of the hardness of the reference group Fe65 powder cladding layer is obvious, and the hardness of H13 steel is quite low. In 700℃ high temperature oxidation comparison test, the oxidation resistances of the orthogonal group cladding layers with proper Al element addition are better than that of the reference group Fe65 powder cladding layers and H13 steel. The oxidation weight gain of the orthogonal group 8 H cladding layer is only32% of Fe65 alloy powder cladding layer and 8.5% of H13 steel, which can demonstrate the excellent high temperature oxidation resistance.