Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment
The microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel after isothermal treatment for 2-20 h at 1100℃ was studied. The morphology evolution of austenite grain was observed and the grain size was quantitatively characterized. The change of element content in austenite and ferrite phase...
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| Format: | Article |
| Language: | zho |
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Journal of Materials Engineering
2020-01-01
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| Series: | Cailiao gongcheng |
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| Online Access: | http://jme.biam.ac.cn/CN/Y2020/V48/I1/70 |
| _version_ | 1797967121468096512 |
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| author | FENG Han WANG Bao-shun WU Xiao-han WANG Man NAI Qi-liang SONG Zhi-gang |
| author_facet | FENG Han WANG Bao-shun WU Xiao-han WANG Man NAI Qi-liang SONG Zhi-gang |
| author_sort | FENG Han |
| collection | DOAJ |
| description | The microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel after isothermal treatment for 2-20 h at 1100℃ was studied. The morphology evolution of austenite grain was observed and the grain size was quantitatively characterized. The change of element content in austenite and ferrite phase was measured. The effect of microstructure evolution on the anisotropy of volume fraction of ferrite phase and low temperature impact toughness of test steels was analysed subsequently. The results show that with the increase of holding time, there is obvious accumulation, growth and coarsening of austenite grain, accompanied by significant changes in grain morphology. The volume fraction of rod-like crystal grains with <i>a/b</i> value above 4.0 dropped from nearly 20% to below 5%, and that of equiaxed grains with <i>a/b</i> value between 1.0 and 1.9 increases significantly, while the number of grains with size above 20 <i>μ</i>m increases rapidly. The prolongation of the holding time makes molybdenum and chromium elements diffuse and enrich to the ferrite phase further, which leads to the increase of pitting resistance equivalent number (PREN) value in ferrite phase. The significant decrease in the volume fraction of slender rod-like austenite crystallites is the primary reason for the improvement in anisotropy of austenite volume fraction and the increase of low temperature impact toughness of test steel. |
| first_indexed | 2024-04-11T02:25:07Z |
| format | Article |
| id | doaj.art-b9012d00660f4d4482b2ce267d408a5d |
| institution | Directory Open Access Journal |
| issn | 1001-4381 1001-4381 |
| language | zho |
| last_indexed | 2024-04-11T02:25:07Z |
| publishDate | 2020-01-01 |
| publisher | Journal of Materials Engineering |
| record_format | Article |
| series | Cailiao gongcheng |
| spelling | doaj.art-b9012d00660f4d4482b2ce267d408a5d2023-01-02T22:50:05ZzhoJournal of Materials EngineeringCailiao gongcheng1001-43811001-43812020-01-01481707610.11868/j.issn.1001-4381.2018.00122520200110Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatmentFENG Han0WANG Bao-shun1WU Xiao-han2WANG Man3NAI Qi-liang4SONG Zhi-gang5Institute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China;Special Materials Research Institute, Zhejiang Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313028, Zhejiang, ChinaInstitute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China;Special Materials Research Institute, Zhejiang Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313028, Zhejiang, ChinaSpecial Materials Research Institute, Zhejiang Jiuli Hi-Tech Metals Co., Ltd., Huzhou 313028, Zhejiang, ChinaInstitute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China;The microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel after isothermal treatment for 2-20 h at 1100℃ was studied. The morphology evolution of austenite grain was observed and the grain size was quantitatively characterized. The change of element content in austenite and ferrite phase was measured. The effect of microstructure evolution on the anisotropy of volume fraction of ferrite phase and low temperature impact toughness of test steels was analysed subsequently. The results show that with the increase of holding time, there is obvious accumulation, growth and coarsening of austenite grain, accompanied by significant changes in grain morphology. The volume fraction of rod-like crystal grains with <i>a/b</i> value above 4.0 dropped from nearly 20% to below 5%, and that of equiaxed grains with <i>a/b</i> value between 1.0 and 1.9 increases significantly, while the number of grains with size above 20 <i>μ</i>m increases rapidly. The prolongation of the holding time makes molybdenum and chromium elements diffuse and enrich to the ferrite phase further, which leads to the increase of pitting resistance equivalent number (PREN) value in ferrite phase. The significant decrease in the volume fraction of slender rod-like austenite crystallites is the primary reason for the improvement in anisotropy of austenite volume fraction and the increase of low temperature impact toughness of test steel.http://jme.biam.ac.cn/CN/Y2020/V48/I1/70duplex stainless steelisothermal treatmentgrain morphologyanisotropyimpact toug-hness |
| spellingShingle | FENG Han WANG Bao-shun WU Xiao-han WANG Man NAI Qi-liang SONG Zhi-gang Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment Cailiao gongcheng duplex stainless steel isothermal treatment grain morphology anisotropy impact toug-hness |
| title | Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment |
| title_full | Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment |
| title_fullStr | Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment |
| title_full_unstemmed | Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment |
| title_short | Microstructure evolution of 022Cr25Ni7Mo4N duplex stainless steel during isothermal treatment |
| title_sort | microstructure evolution of 022cr25ni7mo4n duplex stainless steel during isothermal treatment |
| topic | duplex stainless steel isothermal treatment grain morphology anisotropy impact toug-hness |
| url | http://jme.biam.ac.cn/CN/Y2020/V48/I1/70 |
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