郝建军, 杨泽宇, 马璐萍, 赵建国, 刘敬春. Fe-Cr-C-V等离子堆焊层改善旋耕刀耐磨性和冲击韧性[J]. 农业工程学报, 2019, 35(3): 24-30. DOI: 10.11975/j.issn.1002-6819.2019.03.004
    引用本文: 郝建军, 杨泽宇, 马璐萍, 赵建国, 刘敬春. Fe-Cr-C-V等离子堆焊层改善旋耕刀耐磨性和冲击韧性[J]. 农业工程学报, 2019, 35(3): 24-30. DOI: 10.11975/j.issn.1002-6819.2019.03.004
    Hao Jianjun, Yang Zeyu, Ma Luping, Zhao Jianguo, Liu Jingchun. Fe-Cr-C-V plasma surfacing layer improving wear resistance and impact toughness of rotary blade[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(3): 24-30. DOI: 10.11975/j.issn.1002-6819.2019.03.004
    Citation: Hao Jianjun, Yang Zeyu, Ma Luping, Zhao Jianguo, Liu Jingchun. Fe-Cr-C-V plasma surfacing layer improving wear resistance and impact toughness of rotary blade[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(3): 24-30. DOI: 10.11975/j.issn.1002-6819.2019.03.004

    Fe-Cr-C-V等离子堆焊层改善旋耕刀耐磨性和冲击韧性

    Fe-Cr-C-V plasma surfacing layer improving wear resistance and impact toughness of rotary blade

    • 摘要: 为解决农机触土部件耐磨性差、失效频繁等问题,该文采用等离子堆焊技术在65Mn钢基体上制备Fe-Cr-C-V堆焊层;利用金相显微镜、X射线衍射仪分析了堆焊层的显微组织和物相构成;利用显微硬度计、往复式摩擦磨损试验机、自制土槽磨损试验机、冲击试验机等设备测试了堆焊层的显微硬度、耐磨性及冲击韧性。结果表明,堆焊层与基体呈良好的冶金结合,Fe-Cr-C-V堆焊层主要由α-Fe、Cr7C3、M7C3(Fe,Cr7C3)、Fe-Cr固溶体、VC等组成。与65Mn淬火钢相比,Fe-Cr-C-V堆焊层的维氏硬度提高了75%,磨损质量降低了约67%。与Fe-Cr-C堆焊层相比,Fe-Cr-C-V堆焊层维氏硬度提高了HV0.5100,冲击韧性提高了21%。与常用的65Mn铲尖相比,有Fe-Cr-C-V堆焊层的深松铲铲尖磨损质量减少了78%,与常用60Si2Mn旋耕刀相比,有Fe-Cr-C-V堆焊层的旋耕刀平均磨损质量减小约50%。该研究可为延长旋耕刀使用寿命提供参考。

       

      Abstract: Abstract: In order to solve the problems of poor wear resistance and frequent failure of agricultural machinery contact soil components, Fe-Cr-C-V plasma surfacing layer was prepared on 65Mn steel matrix by plasma surfacing welding technology. Microstructure and phase composition of surfacing layer were analyzed by means of metallographic microscope and X-ray diffraction. Microhardness, wear resistance and impact toughness of surfacing layer were analyzed by means of microhardness tester, reciprocating friction and wear tester, self-made soil-bin wear tester and impact testing machine. The results showed that the cross-section of the surfacing welding specimen showed surfacing region, bonding region and substrate region, the substrate and coating diffused with each other, showing good metallurgical bonding, the coating dilution rate was low, and there were no defects such as porosity and slag inclusion. Fe-Cr-C-V series surfacing layer was mainly composed of α-Fe,Cr7C3,M7C3(Fe,Cr7C3), Fe-Cr solid solution, VC, etc. The microstructure and hard phase morphology of Fe-Cr-C-V surfacing layer were improved. In addition to the original coniferous and hexagonal primary carbides, the dispersed spherical carbides, columnar crystals also appeared. Composed with 65Mn hardened steel, the Vickers hardness of Fe-Cr-C-V series alloy layer was improved by 75% and the wear quality was reduced by about 67%. Compared with Fe-Cr-C series alloy, Fe-Cr-C-V series alloy had finer microstructure, higher hardness, lower wear and better impact toughness. Fe-Cr-C-V surfacing layer had smaller wear quality, more stable wear curve and better wear resistance, this is because that the carbide hard phase dispersed on 65Mn matrix play the role of anti-wear skeleton, while the toughness phase in Fe matrix bonds and solidified the carbide, and the 2 interactions jointly improved the wear resistance of the coating. The refinement and dispersion of hard phase and the appearance of new VC phase were the main reasons for the coating strengthening, while the carbide morphology improved the impact toughness of the coating. The average hardness and impact toughness of Fe-Cr-C alloy were HV0.5710 and 6.2 J/cm2 respectively. The average hardness of Fe-Cr-C-V series alloy layer was HV0.5810, and the impact toughness was 7.5 J/cm2. Fe-Cr-C-V series alloy layer had better wear resistance and impact toughness. Compared with the commonly used 65Mn subsoiler tip, the wear quality of subsoiler tip with surfacing layer was reduced by 78%. Field experiments showed that the average wear quality of the rotary blade with surfacing layer was reduced by about 50% compared with the conventional 60Si2Mn rotary blade without surfacing layer. For the rotary blades without Fe-Cr-C-V surfacing layer, there were obvious wear marks in the intersection area between the cutting edge and the side cutting edge, and the blade passivation was serious, while the surfacing layer on the blade of the rotary blade with surfacing layer remained relatively intact, without serious wear and coating peeling. The average wear quality of rotary blade with surfacing layer was 32 g, and that of ordinary rotary blade without surfacing layer was 60 g. The hardness phase of Fe-Cr-C-V coating studied was uniformly distributed and there was no obvious hardness gradient, which has important reference value for extending the life of soil contact parts of agricultural machinery. In addition, plasma surfacing welding technology was used to prepare Fe-Cr-C-V series wear-resisting coating on the surface of the soil contact parts of agricultural machinery, which has low cost, high efficiency, flexible and convenient technology and high application and promotion value. Compared with the commonly used rotary blades with 65Mn and 60Si2Mn materials, the rotary blades with Fe-Cr-C-V surfacing layer has good wear resistance and excellent comprehensive mechanical properties.

       

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