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7269 |
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Friday, May 06, 2022, Hall G1 10:00 AM Laser Cladding |
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Effect of Nb content on structure and properties of martensitic stainless steel laser cladding layers |
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Kaiping Du* / BGRIMM Technology Group, P.R. China Zhaorao Zeng / BGRIMM Technology Group, China Enze Huang/ BGRIMM Technology Group, China Ziqiang Pi/ BGRIMM Technology Group, China Xing Chen/ BGRIMM Technology Group, China |
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Laser cladding is a technology that uses high-energy-density lasers to quickly melt and solidify alloy powder on the surface of the metal substrate to form a cladding layer with good performance. The alloy powder composition has a significant impact on the cladding layer performanc, including hardness, wear resistance and corrosion resistance. In this work, the effect of Nb content on the microstructure types and phase precipitation rules in the martensitic stainless steel laser cladding layers was investigated through the thermodynamics software. The martensitic stainless steel layers with different Nb content was fabricated on the 45# steel substrate by the laser cladding. The microstructure and element composition of the cladding layers were analyzed by the scanning electron microscope (SEM) and the energy spectrum analyzer (EDS). The hardness, wear resistance and corrosion resistance of the cladding layers were also discussed. The results show that the hard phase NbC content in the cladding layer gradually increases, the content of M23C6 decreases, and the content of Cr in the carbides gradually decreases, with the increasing Nb element content from 0.6 wt.% to 2.2 wt.%. For the performance of the cladding layer, the increase in the content of Nb makes the hardness and wear resistance of the cladding layer increase first and then decrease, but the corrosion resistance gradually increases. Generally speaking, the comprehensive performance is better when the Nb element content in the cladding layer is about 1.4 wt.%. At this time, the microhardness of the cladding layer is 781.00 HV0.2, the friction coefficient is 0.41, and the self-corrosion potential is -350.87 mV. |