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为了提高钢铁材料表面的硬度和耐磨性,采用高频感应加热熔覆方法在45钢基体上制备具有冶金结合的Ni60合金熔覆层。采用金相显微镜、扫描电镜、X射线衍射仪等研究熔覆层的组织结构,用显微硬度计测试熔覆层的显微硬度分布,并对熔覆+淬火+回火处理试样、45钢淬火+回火处理试样和未处理的45钢试样进行耐磨性测试。结果表明:熔覆层组织致密,与基体呈冶金结合,熔覆层的组织主要是在Ni的固溶体上弥散分布着Cr的碳化物、硼化物等硬质相;熔覆层具有较高的硬度,表面硬度(HV0.1)达到了13000MPa,且由表层向基体,硬度呈递减梯度分布;在相同磨损条件下,熔覆+淬火+回火试样相对磨损速度最小,耐磨性较45钢淬火+回火试样提高6.7倍,较未处理的45钢试样提高22.9倍。熔覆层的磨损机制以磨粒磨损和一些脱落硬质相碎片的磨粒磨损为主。
In order to improve the hardness and wear resistance of the steel surface, a Ni60 alloy cladding layer with metallurgical bonding was prepared on a 45 steel substrate by high frequency induction heating cladding method. The microstructure of the cladding layer was studied by metallographic microscope, scanning electron microscopy and X-ray diffraction. The microhardness distribution of the cladding layer was tested by microhardness tester. Steel quenched + temper treated specimens and untreated 45 steel specimens were tested for wear resistance. The results show that the cladding layer is dense and metallurgically bonded with the substrate. The microstructure of the cladding layer is mainly composed of Cr carbides and borides dispersed in Ni solid solution. The cladding layer has high hardness , The surface hardness (HV0.1) reached 13000MPa, and from the surface to the matrix, the hardness showed a decreasing gradient distribution; under the same wear conditions, cladding + quenching + tempering relative wear speed of the smallest, wear resistance than 45 steel Quenched + tempered samples increased by 6.7 times, compared with untreated 45 steel samples increased by 22.9 times. The wear mechanism of the cladding layer is mainly abrasive wear and abrasive wear of some exfoliated hard phase fragments.