La2O3对高碳钢堆焊金属组织与耐磨性的影响

Effect of La_2O_3 on Microstructure and Wear Resistance of High Carbon Steel Hardfacing Metal

研制了不同La2O3加入量的高碳钢堆焊用药芯焊丝,并制作了相应的堆焊试样。采用金相显微镜对其显微组织进行了观察,X射线衍射仪对其相组成进行了分析,洛氏硬度计和砂带式摩擦磨损试验机对其宏观硬度和耐磨性进行了检测,场发射扫描电子显微镜对其磨损表面进行了观察。结果表明:堆焊金属的组织主要由黑色针状马氏体、白色网状高合金马氏体及残余奥氏体组成。随着La2O3加入量的增加,高合金马氏体含量增加,堆焊金属的硬度和耐磨性也增加,当La2O3加入量为3.44%(质量分数)时,二者均达到最大值。堆焊金属中加入La2O3使初生奥氏体晶粒细化,提高了其基体组织的强硬性,与作为耐磨相的高合金马氏体共同作用,使堆焊金属的耐磨性提高。

The flux cored wire with different La2O3 additions was developed. The microstructure of the hardfacing The phase tion. The metal was observed by op microscopy. structure was determined by X-ray diffrac- hardness and wear resistance of the hardfac-ing metal were measured by Rockwell hardness tester and abrasive belt type wear testing machine respective- ly. The worn-out surface morphology was observed by field emission scanning electron microscope. The re- sults indicated that the microstructure of the hardfacingmetal was composed of the black needle-like martens- ite, white reticular high alloy martensite and retained austenite. With increase of La203 addition, the a- mount of the high alloy martensite increases, so do the hardness and wear resistance of the hardfacing metal They both reach the maximum when the La203 addition is 3.44%. The primary austenite grain will be defined with La203 adding and increase the strength and toughness of the matrix microstructure. Combined with the high alloy martensite, the wear resistance phase could be contributed to the increase of the wear resistance of the hardfacing metal