Abstract:
Abstract: M
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6-WC (M: Cr, W, Fe) dual-carbide reinforced Fe-based coating was fabricated on the surface of a 16Mn steel by laser cladding W-Fe60-C alloy powders under the optimized parameters of laser power 1.5 kW, scanning velocity 4 mm/s and powder feeding rate 10 g/min, and microstructure and phase composition of coating were further characterized. Thermodynamic calculation was also performed with Thermo-Calc software on the basis of a commercially available Fe-based Alloys' database to explore the solidification process of the coating. In addition, a comparative study on the microhardness and wear behavior of pure Fe60 alloy coating, WC reinforced Fe-based coating and M
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6-WC dual-carbide reinforced Fe-based coating was conducted. Experimental results showed that M
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6-WC dual-carbide reinforced Fe-based coating was mainly composed of dendritic matrix α-Fe, reinforcing phases W, WC and M
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6. M
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6 carbide was distributed in the inter-dendritic region with a continuous network structure, and block-shaped WC particles grew with the residual W as a nucleation core and distributed in the coating. Combined to the microstructure and thermodynamic calculation results, the solidification process in the M
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6-WC dual-carbides reinforced Fe-based coating during laser cladding process was liquid+W→liquid+W+WC→liquid+W+WC+γ-(Fe, Ni) dendrite→WC+W+γ-(Fe, Ni) dendrite+M
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6→WC+W+α-Fe dendrite+M
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6. The average microhardness of M
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6-WC dual-carbide reinforced Fe-based coating was about 835.3 HV
0.5, which was 230 HV
0.5 and 180 HV
0.5 higher than that of pure Fe60 alloy coating (604.6 HV
0.5) and WC-reinforced Fe-based coating (658.9 HV
0.5), respectively. Furthermore, the wear rate of M
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6-WC dual-carbide reinforced Fe-based coating was about 3.44×10
−6mm
3/mN, which was about 24.7 and 2.3 times lower than that of pure Fe60 alloy cladding 8.51×10
−5 mm
3/(N·m) and WC reinforced Fe-based coating 7.98×10
−6 mm
3/(N·m), respectively.