双液金属复合耐磨板厚度对复合层组织和性能的影响

利用双液铸造液膜连接工艺制备大平面的低碳钢/高铬铸铁耐磨板。采用SEM,EDS对复合层进行组织观察及成分分析。结果表明:不同厚度的复合板从低碳钢侧至高铬铸铁侧可以分为低碳钢→珠光体过渡层→复合层→高铬铸铁过渡层,双金属复合层完全实现了冶金结合。通过对复合层区域进行显微硬度分析,从低碳钢至高铬铸铁侧的显微硬度在345~1260HV范围梯度分布。复合层的显微组织主要为γ-Fe+粒状碳化物。高铬铸铁过渡层奥氏体组织呈现垂直复合层方向的树枝状生长,并随着耐磨板厚度的增加,奥氏体生长的方向性逐渐消失。根据低碳钢的温度变化初步建立了相关的温度场数学模型。

Effect of Two-liquid Bimetal Wear Resistance Plate Thickness on Microstructures and Properties of Composition Layer

Two‐liquid bimetal composite casting through the liquid film bond technology can realize large metallurgical composite plane to prepare the two‐liquid bimetal wear resistance plate between low carbon steel and high chromium cast iron ,w hich can effectively avoid the insufficient heat quanti‐ty of the later poured high temperature liquid metal with the conventional liquid‐liquid composite tech‐nology .The microstructure and composition of the composition layer were detected with SEM and EDS .The results show that ,the sequence of the microstructure from the low carbon steel to the high chromium cast iron is as follow s:low carbon steel → pearlite transition layer → composition layer →high chromium cast iron transition layer .The Vickers hardness of composition layer region is from 345 to 1260 .The microstructure of the composition layer isγ‐Fe and granular carbide .The morpholo‐gy of γ‐Fe in high chromium cast iron layer presents the distinct directional dendritic crystal grow th that is perpendicular to the composition layer ,but the γ‐Fe directivity gradually disappears with the increment of the wear resistance plate thickness .The temperature field mathematical model of the low carbon steel is preliminarily developed for providing a quantitative analysis to the two‐liquid bimetal composition technology .