含硼铁基耐磨复合材料的研制

Development of Fe-based Wear Resistant Composite Material Containing Boron

采用等离子熔覆技术制备硼化物强化铁基堆焊合金,借助OM、SEM和XRD等方法对合金组织和硼化物相形貌进行了分析,并与未加入硼的Fe-Cr-C堆焊合金进行对比。结果表明:向堆焊合金中加入2.5%硼,能诱发基体的马氏体转变,使堆焊层形成大量硼化物,从而改善耐磨性;硼化物由大量层片状M23(C,B)6和少量蜂窝状M7(C,B)3相组成,BC4与Cr2B的数量较少;加入2.5%硼的堆焊层中形成的大量高硬度硼化物分布在具有较高强韧性的马氏体和奥氏体上,使其具有最佳的耐磨性。

Fe-based hard-facing alloy reinforced with borides were prepared under plasma transferred arc weld-surfacing process（PTA）.The microstructure and borides morphology were investigated by means of OM,SEM and XRD,which was compared with the Fe-Cr-C hard-facing alloy.The results show that the martensite transformation of the matrix is induced and high volume fraction of borides are formed in the hard-facing layers as a result of the addition of 4.5%B in hard-facing alloys,which leads to the improvement of wear resistance significantly.The borides consists of high volume fraction of plate M23（C,B）6 and little volume fraction of honeycomb M7（C,B）3;the content of BC4 and Cr2B is very little.The microstructure with a high volume fraction of borides possessing high microhardness are distributed in the martensite and austenite matrix with high strength and toughness as the addition of 2.5% B in Fe-Cr-C hard-facing alloy,which ensure that the hard-facing layers has a excellent wear resistance.