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以钛铁粉、铬粉、铁粉和碳的前驱体(蔗糖)等为原料,通过前驱体碳化复合技术制备了碳化复合粉,并利用等离子熔覆技术在Q235钢表面制备了Fe-Cr-C和Fe-Cr-C-Ti涂层.采用X射线衍射和扫描电镜对涂层的相组成和显微组织结构进行了分析.结果表明:Fe-Cr-C涂层由(Cr,Fe)_7C_3初生碳化物和菊花瓣状分布共晶碳化物(Cr,Fe)_7C_3与奥氏体组织组成;Fe-Cr-C-Ti涂层由原位合成的TiC相和(Cr,Fe)_7C_3共晶相与奥氏体相构成.这两种涂层与基体之间都是冶金结合.涂层中碳化物TiC的体积分数呈现梯度分布,并且涂层的熔合区和中部区域TiC颗粒形状多为等轴状颗粒,涂层的表层区域部分TiC颗粒多为树枝晶颗粒.与Fe-Cr-C涂层相比较,Fe-Cr-C-Ti涂层的抗开裂性更好.Fe-Cr-C和Fe-Cr-C-Ti两涂层的平均显微硬度约是750HV_(0.2),是基体金属的3.2倍,从涂层表面到熔合区相差不大.
Fe-Cr-Fe-Cr alloy was prepared on the surface of Q235 steel by plasma cladding technology using titanium-iron powder, chromium powder, iron powder and carbon precursor (sucrose) as raw materials, C and Fe-Cr-C-Ti coatings.The phase composition and microstructure of the coating were analyzed by X-ray diffraction and scanning electron microscopy.The results show that the coating consists of (Cr, Fe) _7C_3 primary carbides and chrysanthemum petals distributed eutectic carbide (Cr, Fe) _7C_3 and austenitic microstructure; Fe-Cr-C-Ti coating by in situ synthesis of TiC and (Cr, Fe) _7C_3 Crystal phase and austenite phase.The metallurgical bond between the two coatings and the matrix.The volume fraction of carbide TiC in the coating presents a gradient distribution and the shape of the TiC particles in the fusion zone and the middle zone of the coating is mostly TiC particles are mostly dendritic particles in the surface region of the coating.Compared with Fe-Cr-C coating, the crack resistance of Fe-Cr-C-Ti coating is better.Fe-Cr- The average microhardness of both C and Fe-Cr-C-Ti coatings is about 750 HV-0.2, which is 3.2 times that of the base metal. The difference between the coating surface and the fusion zone is not significant.