埋弧堆焊TiC颗粒增强复合涂层的组织与性能

Microstructure and performance of submerged-arc weld clad TiC particle reinforced composite coating

以TiFe粉、Cr粉、Ni粉、Fe粉、胶体石墨等为原料,利用合金粉粒埋弧堆焊技术在Q235钢表面原位反应合成TiC颗粒增强Fe基复合涂层。利用SEM,XRD和EDS等分析了涂层的显微组织,并在室温干滑动磨损条件下测试该涂层的耐磨性能。结果表明:利用合金粉粒埋弧堆焊技术,可以原位合成粒径在2μm以下、弥散分布的TiC颗粒。涂层组织由TiC颗粒、马氏体和奥氏体构成。涂层平均显微硬度达601HV0.2,约是碳钢基体的3倍。由于TiC颗粒和马氏体的抗磨损性能使涂层具有优异的耐磨性能,因此涂层磨损质量约是基体金属的1/10。埋弧堆焊双层涂层与单层涂层相比,马氏体含量减少,奥氏体和TiC含量增加,耐磨性更好。

TiC particle reinforced Fe-based composite coatings were in situ synthesized on the surface of Q235 steel by submerged-arc welding（SAW） using mixture of TiFe,Cr,Ni,Fe and colloidal graphite powers,etc.Microstructures of the coatings were observed by scanning electron microscopy（SEM）,the phases in the coatings were determined by X-ray diffractometery（XRD）,and the wear resistance of the composite coatings was evaluated under dry sliding wear test conditions at room temperature.The results indicate that the fine TiC particles with diameter less than 2 μm are synthesized by using submerged-arc welding process and distributed in the matrix.The coating consists of TiC particles,martensite and austenite.The microhardness of the coating is 601HV0.2,which is 3 times larger than that of the base material.The wear mass loss of Q235 base material is 10 times more than that of the coating.Compared with the single-layer composite coating,the double composite coating shows better wear resistance due to the increase of austenite and TiC content and the decrease of martensite content.