等离子弧熔覆Fe-C-B-V系耐磨堆焊层的组织及性能研究

Study on Microstructure and Performance of Fe-C-B-V Wear Resistant Surfacing Layer by Plasma Arc Clading

以硼铁、高碳铬铁、钒铁为原料,采用等离子弧熔覆技术在Q345钢表面堆焊Fe-C-B-V系铁基合金。使用金相显微镜、扫描电镜和X射线衍射仪等研究了堆焊层的显微组织;分别使用维氏硬度计和冲击试验机测量堆焊层的显微硬度和冲击韧性。结果表明,堆焊层显微组织主要由马氏体、网格状Fe_(3)(C,B)和Fe_(2)B、弥散分布的碳化物及硼化物等(如VB_(2)、VC、Cr_(2)B)硬质相构成;堆焊层的平均硬度高达904.58 HV10、冲击功为68.5 J。堆焊过程中形成的硼化物、碳化物作为硬质相提高了堆焊层的硬度和耐磨性,形成的碳化钒使组织从鱼骨状变成网格状,细化了晶粒,提高了堆焊层的冲击韧性。

Fe-C-B-V iron-based alloy was cladded on the surface of Q345 steel by plasma arc surfacing technology,using ferroboron,high carbon chromium iron and ferrovanadium as raw materials.The microhardness and impact toughness of the surfacing layer were measured by using the Vickers hardness and impact test machine,respectively.The results show that the microstructure of the surfacing layer is mainly composed of martensite,grid shaped Fe_(3)(C,B)and Fe_(2)B,the dispersal distribution of carbides and borides(e.g VB_(2),VC and Cr_(2)B).The average hardness of the surfacing layer is up to 904.58 HV10,its impact energy is 68.5 J.The carbides and borides formed during surfacing welding ascribe to improve the hardness and wear resistance of the surfacing layer,meanwhile,the formed vanadium carbide makes the microstructure change from fishbone to grid,refining the grain,then,the impact toughness of the surfacing layer improves.