Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding
In this study, the effect of heat input on the microstructure and its correlation with the immersion corrosion properties of TC4 welded joints by Keyhole tungsten inert gas (TIG) process was researched. The combined corrosion mechanism between immersion corrosion and electrochemical corrosion was es...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2024-01-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423032222 |
| _version_ | 1797338310965723136 |
|---|---|
| author | Jinhong Du Hongbing Liu Fei Wang Wen Bao Naikang Feng Huan Li Tao Liu |
| author_facet | Jinhong Du Hongbing Liu Fei Wang Wen Bao Naikang Feng Huan Li Tao Liu |
| author_sort | Jinhong Du |
| collection | DOAJ |
| description | In this study, the effect of heat input on the microstructure and its correlation with the immersion corrosion properties of TC4 welded joints by Keyhole tungsten inert gas (TIG) process was researched. The combined corrosion mechanism between immersion corrosion and electrochemical corrosion was established. The results showed that immersion corrosion formed a passivation film on the surface of the welded joint and formed a minimal number of pitting pits. After immersion, electrochemical corrosion testing was carried out. Due to the existence of the passivation film, the self-corrosion potential increased from-0.6 V ∼ −0.2 V–0.1 V–0.6 V, and the self-corrosion current density decreased and the fitting impedance of the film increased. These all showed that the corrosion resistance of the joint was enhanced after immersion. However, due to the combined effect of immersion corrosion and electrochemical corrosion, the potential difference between the surface passivation film and the internal metal was sufficiently large to induce pitting corrosion on the surface. After the breakdown of the passivation film, spot corrosion pits formed. Microcracks propagated along the primary β grain boundary and the α′ phase interface, and continuous corrosion for a long time may even lead to cracking failure of the welded joints. With the increase of heat input, the self-corrosion potential and the self-corrosion current density of immersion corrosion increased firstly and then decreased. The fitting film resistance value of the impedance decreased firstly and then increased. The aforementioned findings indicated that as the heat input increased, the corrosion properties of the joints firstly deteriorated and then improved. |
| first_indexed | 2024-03-08T09:29:10Z |
| format | Article |
| id | doaj.art-c6163c9a036e4ba1af13030c4f194c0e |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-08T09:29:10Z |
| publishDate | 2024-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-c6163c9a036e4ba1af13030c4f194c0e2024-01-31T05:43:48ZengElsevierJournal of Materials Research and Technology2238-78542024-01-012824552465Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG weldingJinhong Du0Hongbing Liu1Fei Wang2Wen Bao3Naikang Feng4Huan Li5Tao Liu6School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, ChinaSchool of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, China; Shanghai Collaborative Innovation Center of Laser Advanced Manufacturing Technology, Shanghai, 150001, China; Corresponding author. School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, China.School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, China; Shanghai Collaborative Innovation Center of Laser Advanced Manufacturing Technology, Shanghai, 150001, China; Corresponding author. School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, China.School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, ChinaSchool of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai, 210620, ChinaTianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin, 300072, ChinaZhejiang Shenji Titanium Industry Co. Ltd. Zhejiang 313300, ChinaIn this study, the effect of heat input on the microstructure and its correlation with the immersion corrosion properties of TC4 welded joints by Keyhole tungsten inert gas (TIG) process was researched. The combined corrosion mechanism between immersion corrosion and electrochemical corrosion was established. The results showed that immersion corrosion formed a passivation film on the surface of the welded joint and formed a minimal number of pitting pits. After immersion, electrochemical corrosion testing was carried out. Due to the existence of the passivation film, the self-corrosion potential increased from-0.6 V ∼ −0.2 V–0.1 V–0.6 V, and the self-corrosion current density decreased and the fitting impedance of the film increased. These all showed that the corrosion resistance of the joint was enhanced after immersion. However, due to the combined effect of immersion corrosion and electrochemical corrosion, the potential difference between the surface passivation film and the internal metal was sufficiently large to induce pitting corrosion on the surface. After the breakdown of the passivation film, spot corrosion pits formed. Microcracks propagated along the primary β grain boundary and the α′ phase interface, and continuous corrosion for a long time may even lead to cracking failure of the welded joints. With the increase of heat input, the self-corrosion potential and the self-corrosion current density of immersion corrosion increased firstly and then decreased. The fitting film resistance value of the impedance decreased firstly and then increased. The aforementioned findings indicated that as the heat input increased, the corrosion properties of the joints firstly deteriorated and then improved.http://www.sciencedirect.com/science/article/pii/S2238785423032222Keyhole TIG weldingHeat inputMicrostructureElectrochemical corrosion propertiesImmersion corrosion propertiesCombined corrosion mechanism |
| spellingShingle | Jinhong Du Hongbing Liu Fei Wang Wen Bao Naikang Feng Huan Li Tao Liu Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding Journal of Materials Research and Technology Keyhole TIG welding Heat input Microstructure Electrochemical corrosion properties Immersion corrosion properties Combined corrosion mechanism |
| title | Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding |
| title_full | Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding |
| title_fullStr | Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding |
| title_full_unstemmed | Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding |
| title_short | Immersion and electrochemical corrosion properties and combined corrosion mechanism of TC4 alloy by keyhole TIG welding |
| title_sort | immersion and electrochemical corrosion properties and combined corrosion mechanism of tc4 alloy by keyhole tig welding |
| topic | Keyhole TIG welding Heat input Microstructure Electrochemical corrosion properties Immersion corrosion properties Combined corrosion mechanism |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423032222 |
| work_keys_str_mv | AT jinhongdu immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT hongbingliu immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT feiwang immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT wenbao immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT naikangfeng immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT huanli immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding AT taoliu immersionandelectrochemicalcorrosionpropertiesandcombinedcorrosionmechanismoftc4alloybykeyholetigwelding |