高锰钢表面高速激光熔覆Ni60涂层组织与性能

Microstructure and properties of high-speed laser cladding Ni60 coating on surface of high manganese steel

  • 摘要: 采用高速激光熔覆系统在破碎机锤头中常用的材料高锰钢表面制备了Ni60耐磨熔覆层。通过正交试验极差分析优化得到最佳工艺参数,采用渗透探伤、显微硬度计、OM,XRD,BSE和摩擦磨损试验对熔覆层宏观形貌、硬度、微观形貌、物相、摩擦系数和磨损量进行观察与测试。结果表明,当激光功率为1 200 W、扫描速度为4 mm/s、送粉速度为7.5 g/min时,熔覆层表面成形质量良好,表面硬度可达811.41 HV,约为基材的2.8倍,摩擦系数较基材下降37.7%,耐磨性提高1.6倍。熔覆层主要由γ-Ni树枝晶组成,其中弥散分布的硬质相CrB,Cr7C3和Cr23C6可显著提高熔覆层的耐磨性。

     

    Abstract: High-speed laser system was used to prepare Ni60 wear-resistant cladding layer on surface of high manganese steel that was commonly used in crusher hammer. The optimum process parameters were obtained by orthogonal test range analysis. The macroscopic morphology, hardness, microstructure, phase, friction coefficient and wear amount of cladding layer were observed and tested by penetration testing, microhardness tester, OM, XRD, BSE and friction and wear test. The results showed that when laser power was 1 200 W, scanning speed was 4 mm/s, and powder feeding speed was 7.5 g/min, surface forming quality of cladding layer was good, surface hardness was 811.41 HV, which was about 2.8 times of substrate. Friction coefficient decreased by 37.7% compared with substrate and wear resistance was increased by 1.6 times. Cladding layer was mainly composed of γ-Ni dendrites, in which hard phases CrB, Cr7C6 and Cr23C3 significantly improved wear resistance of cladding.

     

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