Vacuum Carburization and Passivation of SUS 410 Stainless Steel and Their Improvement of the Corrosion Resistance
| Autor: | Yao-Sheng Lin, 林耀生 |
|---|---|
| Rok vydání: | 2000 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 88 As a molding and cutting material for plastic forming industry, tool steel is always used for its excellent wear resistance. But its poor corrosion resistance limits the productivity of plastics. On the contrary, stainless steel owns excellent corrosion resistance but poor wear resistance. To improve the surface hardness of 410 martensitic stainless steel, a heat treatment of vacuum carburization process was carried out, and then was followed by electropolish, chemical polish, mechanical polish, and chemical passivation processes to recuperate the corrosion resistance of the steel. In this experiment, the process parameters, such as gas composition, gas flow rate, diffusion time, carburization temperature and time etc., all had been optimized. The surface condition and carbon and chromium distribution in the surface layer were examined and analyzed by EPMA、XRD、SEM-EDX and GDS. It was expected to develop a surface modified 410 stainless steel with better wear and corrosion resistance. Experiment results show that after the optimized vacuum carburizing process, SUS 410 stainless steel may reach a hardness of HV650 in surface layer and HV460 inside the matrix with fully martensite structure. After some surface treatment, such as electropolishing, chemical polishing, and mechanical polishing, the corrosion resistance of the alloy surface can not be improved significantly, but can be improved by the final chemical passivation process. Only the alloy sample treated by the vacuum carburization followed by chemical polishing and chemical passivation shows a worse corrosion resistance, because of its porous surface structure which can not form a continuous chromium oxide layer. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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