Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings
20Cr-8Ni stainless steel is used to manufacture heavy castings in industrial practice. Owing to the slow solidification rate of heavy castings, the as-cast structure is usually coarse, which reduces the mechanical properties. To refine the solidification structure, the effect of titanium addition on...
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MDPI AG
2020-04-01
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| Online Access: | https://www.mdpi.com/2075-4701/10/4/529 |
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| author | Qiming Wang Guoguang Cheng Yuyang Hou |
| author_facet | Qiming Wang Guoguang Cheng Yuyang Hou |
| author_sort | Qiming Wang |
| collection | DOAJ |
| description | 20Cr-8Ni stainless steel is used to manufacture heavy castings in industrial practice. Owing to the slow solidification rate of heavy castings, the as-cast structure is usually coarse, which reduces the mechanical properties. To refine the solidification structure, the effect of titanium addition on the as-cast structure and high-temperature tensile property was investigated in the laboratory. The ingots with 0.0036, 0.2, and 0.45 mass percent titanium were produced in the laboratory. On the basis of experiment and thermodynamic calculation through Thermo-Calc software, the typical inclusions changed from dual phase Si-Mn-Ti oxides to pure TiN or complex Ti<sub>2</sub>O<sub>3</sub> + TiN with titanium content increasing. The equiaxed grain ratio of ingot increased from 51 percent to nearly 100 percent, and the size of equiaxed grain decreased owing to heterogeneous nucleation of δ-Fe. Besides, the equilibrium solidification model changed from the FA model to the F model, and the mass fraction of ferritic phase in ingots increased from 24.8 to 42.6 percent. As a result, the yield strength and ultimate tensile strength of ingots increased gradually, but the tensile elongation changed little owing to the increase of ferritic phase mass fraction and decrease of equiaxed grain size. |
| first_indexed | 2024-03-10T20:21:28Z |
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| id | doaj.art-9f48118d71db427cb67e57d137ff119d |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T20:21:28Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
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| series | Metals |
| spelling | doaj.art-9f48118d71db427cb67e57d137ff119d2023-11-19T22:09:44ZengMDPI AGMetals2075-47012020-04-0110452910.3390/met10040529Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy CastingsQiming Wang0Guoguang Cheng1Yuyang Hou2State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaState Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaState Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China20Cr-8Ni stainless steel is used to manufacture heavy castings in industrial practice. Owing to the slow solidification rate of heavy castings, the as-cast structure is usually coarse, which reduces the mechanical properties. To refine the solidification structure, the effect of titanium addition on the as-cast structure and high-temperature tensile property was investigated in the laboratory. The ingots with 0.0036, 0.2, and 0.45 mass percent titanium were produced in the laboratory. On the basis of experiment and thermodynamic calculation through Thermo-Calc software, the typical inclusions changed from dual phase Si-Mn-Ti oxides to pure TiN or complex Ti<sub>2</sub>O<sub>3</sub> + TiN with titanium content increasing. The equiaxed grain ratio of ingot increased from 51 percent to nearly 100 percent, and the size of equiaxed grain decreased owing to heterogeneous nucleation of δ-Fe. Besides, the equilibrium solidification model changed from the FA model to the F model, and the mass fraction of ferritic phase in ingots increased from 24.8 to 42.6 percent. As a result, the yield strength and ultimate tensile strength of ingots increased gradually, but the tensile elongation changed little owing to the increase of ferritic phase mass fraction and decrease of equiaxed grain size.https://www.mdpi.com/2075-4701/10/4/529stainless steelas-cast structuremicrostructuretensile propertytitanium content |
| spellingShingle | Qiming Wang Guoguang Cheng Yuyang Hou Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings Metals stainless steel as-cast structure microstructure tensile property titanium content |
| title | Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings |
| title_full | Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings |
| title_fullStr | Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings |
| title_full_unstemmed | Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings |
| title_short | Effect of Titanium Addition on As-Cast Structure and High-Temperature Tensile Property of 20Cr-8Ni Stainless Steel for Heavy Castings |
| title_sort | effect of titanium addition on as cast structure and high temperature tensile property of 20cr 8ni stainless steel for heavy castings |
| topic | stainless steel as-cast structure microstructure tensile property titanium content |
| url | https://www.mdpi.com/2075-4701/10/4/529 |
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