论文部分内容阅读
采用药芯焊丝自保护明弧焊方法制备了含有11%~13%Cr、3.5%~3.8%C、2.1%~2.3%Nb、0.6%~0.7%B、0%~4.0%Mo(质量分数)且宏观硬度高达65 HRC的耐磨合金。采用光学显微镜、X射线衍射仪和扫描电镜,研究了钼含量对其显微组织及耐磨性的影响。结果表明:随着钼含量增加,合金组织整体细化,形成了强韧性配合良好的奥氏体+针状马氏体复合基体以及韧性更好的M_(23)(C,B)_6+原位析出Nb C耐磨相,脆性变态莱氏体Ld’的形成得到明显抑制。此外,湿砂磨粒磨损试验结果表明,适量Mo减小碳化物间隔尺寸及Nb C颗粒脱落几率,显著改善耐磨性,但如加入过多,合金磨损机制会变为磨粒显微切削。
The method of self-protection arc welding with flux-cored wire was used to prepare the steel with 11% -13% Cr, 3.5% -3.8% C, 2.1% -2.3% Nb, 0.6% -0.7% B and 0% ~ 4.0% Mo ) And macro-hardness of up to 65 HRC wear-resistant alloy. The effects of molybdenum content on its microstructure and wear resistance were studied by optical microscope, X-ray diffraction and scanning electron microscopy. The results show that with the increase of molybdenum content, the microstructure of the alloy is refined as a whole, resulting in a ductile and austenite + acicular martensite composite matrix and better toughness of M_ (23) (C, B) _6 + Precipitation of Nb C wear-resistant phase, brittle metamorphism Ledendum Ld ’formation was significantly inhibited. In addition, the results of wet sand abrasive wear test show that proper amount of Mo can reduce the carbide size and the probability of Nb C particles shedding, and significantly improve the wear resistance. However, if too much is added, the wear mechanism of the alloy becomes abrasive grain micro cutting.