| YIN Yan,HE Ming-ming,LI Hui,ZHAO Kui-an,LIU Ying-bo,ZHANG Rui-hua.Analysis of Microstructure and Carbide Evolution Mechanism of TiC/Fe-Based Cladding Coating by Plasma Cladding[J],52(10):384-393 |
| Analysis of Microstructure and Carbide Evolution Mechanism of TiC/Fe-Based Cladding Coating by Plasma Cladding |
| Received:December 07, 2022 Revised:March 22, 2023 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.10.034 |
| KeyWord:plasma cladding Fe-based powder TiC cladding coating microstructure evolution mechanism |
| Author | Institution |
| YIN Yan |
State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou , China |
| HE Ming-ming |
State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou , China |
| LI Hui |
China Iron & Steel Research Institute Group, Beijing , China;Yangjiang Hardware Knife Cut Industrial Technology Research Institute, Guangdong Yangjiang , China;Sichuan University of Science & Engineering, Sichuan Zigong , China |
| ZHAO Kui-an |
State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou , China |
| LIU Ying-bo |
State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou , China |
| ZHANG Rui-hua |
China Iron & Steel Research Institute Group, Beijing , China;Yangjiang Hardware Knife Cut Industrial Technology Research Institute, Guangdong Yangjiang , China |
|
| Hits: |
| Download times: |
| Abstract: |
| In order to improve the hardness and wear resistance of 3Cr13 martensitic stainless steel, TiC/Fe-based cladding coating was fabricated on the 3Cr13 stainless steel substrate. The homogeneity of the microstructure of the cladding coating and the type of carbides were analyzed, and the evolution mechanism of carbides and effect rule on hardness of carbides of the cladding coating were studied. Spherical TiC/Fe-based cladding coating was fabricated on the 3Cr13 martensitic stainless steel substrate by plasma cladding with coaxial powder-feed. The microstructure distribution of the cladding coating and the microscopic morphological characteristics of the precipitated phase were observed by scanning electron microscopy (SEM). The phase composition of the cladding coating was analyzed by X-ray diffraction (XRD), and the chemical composition and the distribution of elements of the precipitation phase in the cladding coating were analyzed by energy dispersive spectroscopy (EDS). With the knowledge of thermodynamics and kinetics of materials, the evolution mechanism of carbides in cladding coating was analyzed, and the hardness of the cladding coating was measured by the microhardness tester. The un-melted TiC particles appeared homogeneous distribution in the cladding coating. With the increase of TiC content, the contents of Ti and C elements increased in the cladding coating. The atomic percentage of C increased from 26.22% to 49.86%, and the atomic percentage of Ti increased from 0 to 9.56%, which indicated that some of TiC was melted. In addition, the scanning results of element distribution showed that there were cracks in the un-melted spherical TiC, which also indicated that a proportion of TiC had melted in the cladding coating. The microstructure without TiC in the cladding coating was mainly formed by Fe-Cr sosoloid and (Fe, Cr)7C3, while the phases in the TiC/Fe-based cladding coating were mainly Fe-Cr sosoloid and TiC, (Fe, Cr)3C2 and (Fe, Cr)7C3. The precipitated phases in the two kinds of cladding coatings were mainly (Fe, Cr)7C3, but TiC was re-precipitated after melting in the TiC/Fe-based cladding coating. The misfit between the (111) face of TiC and the (0001) face of (Fe3Cr4)C3 was δ=10.87%, so precipitated TiC could be used as effective nucleation particles of (Fe3Cr4)C3 to promote the formation of (Fe3Cr4)C3. With the increase of TiC content, the hardness of the cladding coating also increased. The average microhardness of Fe-based cladding coating and TiC/Fe-based cladding coatings with 10wt.%TiC, 20wt.%TiC and 30wt.%TiC were 641.9HV0.1, 645.4HV0.1, 695.1HV0.1 and 746.3HV0.1 respectively, and the average microhardness was 1.60, 1.61, 1.74 and 1.87 times of the substrate microhardness respectively. The amount of un-melted TiC increased with the increase of the ratios of TiC in the cladding coating. Compared with the cladding coating without TiC, the second phases in the TiC/Fe-based cladding coating included TiC, (Fe, Cr)3C2 besides (Fe, Cr)7C3. The TiC phases included un-melted original spherical TiC particles and newly precipitated fine TiC. (Fe, Cr)3C2 grew with the precipitated TiC as the nucleation core, and then transformed (Fe, Cr)3C2 into more stable (Fe, Cr)7C3. During the rapid cooling process of the molten pool, some of (Fe, Cr)3C2 without transformation were retained. Through summary and analysis of changes in carbides, the evolution process of carbides in the TiC/Fe-based cladding coating can be divided into four stages:the melting of TiC, the re-precipitation of tiny TiC, the formation process of (Fe, Cr)3C2 and the phase transition process of (Fe, Cr)7C3. The hardness of the cladding coating is improved by the original TiC, the re-precipitated TiC, and the (Fe, Cr)7C3 and (Fe, Cr)3C2 of generation as hard phases. Carbides play a fine grain strengthening role in the cladding coating and also improve the hardness of the cladding coating. |
| Close |
|
|
|