30MnB5开沟刀表面铁基合金熔覆层耐磨性与磨损机理研究

Wear Resistance and Wear Mechanism of Fe-based Alloy Cladding Layer on Surface of 30MnB5 Ditch Knife

摘要:

为提升30MnB5开沟刀耐磨性,采用矩形光斑激光熔覆技术制备3种铁基合金熔覆层,通过X射线衍射仪和扫描电镜分析熔覆层相组成与显微组织,结合湿砂橡胶轮及自研入土部件磨损性能试验台试验测试耐磨性。结果表明:3种熔覆层与基体呈良好的冶金结合,2号和3号熔覆层均无裂纹、气孔等缺陷,熔覆层内部均存在大量的胞状晶和硬质相;熔覆层主要由FeC固溶体、Mo61C39、Mo18C7、V4C3、(Fe,C)、WC、SiC及Ni2B等物相组成;湿砂橡胶轮磨损试验及自研入土部件磨损试验均表明3号熔覆层耐磨性最优,因其高Mo含量促成细小胞状细晶组织,且适量V、W元素使VC、WC、Mo基碳化物弥散分布,强化耐磨性能;3组熔覆层的磨损机制均以磨粒磨损为主导,伴随粘着磨损与氧化磨损。3号铁基合金成分可显著提升开沟刀耐磨性,结合30MnB5基材,为低功耗、长寿命农业链式开沟机部件制造提供技术支撑。

Abstract:

Aiming to improve the wear resistance of the 30MnB5 ditch knife, three types of Fe-based alloy cladding layers were fabricated on its surface using rectangular spot laser cladding technology. The phase composition and microstructure of the cladding layers were analyzed by using X-ray diffraction and scanning electron microscopy. Wear resistance was tested through wet sand rubber wheel and self- developed soil incorporation component wear tests. The results indicated that the three cladding layers exhibited good metallurgical bonding with the substrate. and there were no defects such as cracks or pores in the No. 2 and No. 3 cladding layers. There were a large number of cellular crystals and hard phases inside the cladding layers. The cladding layers were primarily composed of Fe C solid solutions, Mo61 C39, Mo18C7, V4C3, (Fe, C), WC, SiC, and Ni2 B, among other phases. Both the wet sand rubber wheel wear test and the self-developed soil incorporation component wear test demonstrated that the 3 cladding layers exhibited the best wear resistance, attributed to its high Mo content which promoted a fine cellular crystalline structure. Additionally, the appropriate amounts of V and W elements resulted in a dispersed distribution of VC, WC, and Mo-based carbides, enhancing the wear resistance. The wear mechanism for all three cladding layers was predominantly abrasive wear, accompanied by adhesive wear and oxidative wear. The composition of the No. 3 Fe-based alloy significantly improved the wear resistance of the ditch knife, combined with the substrate of 30MnB5, providing technical support for the manufacturing of low-power and long-life agricultural chain trenching components.