Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169
Residual stresses (RS) in hot forging severely degrade the machining accuracy and stability of super alloy parts. This is the main reason for deformation during subsequent mechanical machining. RS need recognition, as well as the microstructure and properties achieved by forging. In this study, a si...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-02-01
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| Series: | Aerospace |
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| Online Access: | https://www.mdpi.com/2226-4310/9/2/92 |
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| author | Zibiao Wang Guangsha Hou Yang Zhao Jianfei Sun Jiangzhen Guo Wuyi Chen |
| author_facet | Zibiao Wang Guangsha Hou Yang Zhao Jianfei Sun Jiangzhen Guo Wuyi Chen |
| author_sort | Zibiao Wang |
| collection | DOAJ |
| description | Residual stresses (RS) in hot forging severely degrade the machining accuracy and stability of super alloy parts. This is the main reason for deformation during subsequent mechanical machining. RS need recognition, as well as the microstructure and properties achieved by forging. In this study, a simulation and experimental research on the single-pass compression of GH4169 are presented. RS variations with forging temperature, loading speed, and cooling speed are established by finite element (FE) simulation. Based on the FE results, an experiment is conducted at a temperature of 1020<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mo>℃</mo></mrow></semantics></math></inline-formula>, loading speed of 25 mm/s, and press amount of 16 mm, immediately followed by water cooling. A new layer-stripping method is put forward for the high-efficiency measurement and correction of interior RS. Compared with the traditional strain gauge layer-stripping method, the measurement efficiency of the new layer-stripping method is increased by 10 times. Meanwhile, grain photographs are collected and grain size evolution is summarized; thus, the RS is characterized and evaluated from the angle of grains. It is demonstrated that the RS level rises with the increase in forging temperature, loading speed, and cooling speed, while the cooling method influences both the stress value and distribution. Compressive RS changes to tensile, while the average grain size reduces from the surfaces to the center. In the compressive regions, stress values share the same rules as grain size, while, in the tensile regions, they are contrary. The RS levels are divided according to the grain degree standard. According to the residual stress and grain distribution law of the blank, the optimal position of the part in the blank can be determined. Compared with the center position of the part in the blank, the residual stress of the part is reduced by 70%. The results provide useful strategies for the better design of forging technology, qualification examinations, and subsequent mechanical machining. |
| first_indexed | 2024-03-09T22:54:15Z |
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| institution | Directory Open Access Journal |
| issn | 2226-4310 |
| language | English |
| last_indexed | 2024-03-09T22:54:15Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Aerospace |
| spelling | doaj.art-7abf4eb8416448378750290652c955a02023-11-23T18:14:35ZengMDPI AGAerospace2226-43102022-02-01929210.3390/aerospace9020092Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169Zibiao Wang0Guangsha Hou1Yang Zhao2Jianfei Sun3Jiangzhen Guo4Wuyi Chen5School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, ChinaSchool of Mechanical Engineering and Automation, Beihang University, Beijing 100191, ChinaBeijing Scienkong Technology Co., Ltd., Beijing 100010, ChinaSchool of Mechanical Engineering and Automation, Beihang University, Beijing 100191, ChinaSchool of Mechanical Engineering and Automation, Beihang University, Beijing 100191, ChinaSchool of Mechanical Engineering and Automation, Beihang University, Beijing 100191, ChinaResidual stresses (RS) in hot forging severely degrade the machining accuracy and stability of super alloy parts. This is the main reason for deformation during subsequent mechanical machining. RS need recognition, as well as the microstructure and properties achieved by forging. In this study, a simulation and experimental research on the single-pass compression of GH4169 are presented. RS variations with forging temperature, loading speed, and cooling speed are established by finite element (FE) simulation. Based on the FE results, an experiment is conducted at a temperature of 1020<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mo>℃</mo></mrow></semantics></math></inline-formula>, loading speed of 25 mm/s, and press amount of 16 mm, immediately followed by water cooling. A new layer-stripping method is put forward for the high-efficiency measurement and correction of interior RS. Compared with the traditional strain gauge layer-stripping method, the measurement efficiency of the new layer-stripping method is increased by 10 times. Meanwhile, grain photographs are collected and grain size evolution is summarized; thus, the RS is characterized and evaluated from the angle of grains. It is demonstrated that the RS level rises with the increase in forging temperature, loading speed, and cooling speed, while the cooling method influences both the stress value and distribution. Compressive RS changes to tensile, while the average grain size reduces from the surfaces to the center. In the compressive regions, stress values share the same rules as grain size, while, in the tensile regions, they are contrary. The RS levels are divided according to the grain degree standard. According to the residual stress and grain distribution law of the blank, the optimal position of the part in the blank can be determined. Compared with the center position of the part in the blank, the residual stress of the part is reduced by 70%. The results provide useful strategies for the better design of forging technology, qualification examinations, and subsequent mechanical machining.https://www.mdpi.com/2226-4310/9/2/92residual stressesgrain sizehot forgingsuper alloy |
| spellingShingle | Zibiao Wang Guangsha Hou Yang Zhao Jianfei Sun Jiangzhen Guo Wuyi Chen Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 Aerospace residual stresses grain size hot forging super alloy |
| title | Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 |
| title_full | Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 |
| title_fullStr | Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 |
| title_full_unstemmed | Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 |
| title_short | Characterization of Residual Stresses and Grain Structure in Hot Forging of GH4169 |
| title_sort | characterization of residual stresses and grain structure in hot forging of gh4169 |
| topic | residual stresses grain size hot forging super alloy |
| url | https://www.mdpi.com/2226-4310/9/2/92 |
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