Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding
Keyhole plasma arc welding (PAW) of the super duplex stainless steel (SDSS) is expected to achieve full-penetration joints of medium-thickness plates in a single pass with higher efficiency. However, the unique key-holing processes due to the special constricted arc behaviors cause much different th...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-01-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785422018129 |
| _version_ | 1828054092413403136 |
|---|---|
| author | Qi Wang Guochao Gu Chuanbao Jia Kan Li Chuansong Wu |
| author_facet | Qi Wang Guochao Gu Chuanbao Jia Kan Li Chuansong Wu |
| author_sort | Qi Wang |
| collection | DOAJ |
| description | Keyhole plasma arc welding (PAW) of the super duplex stainless steel (SDSS) is expected to achieve full-penetration joints of medium-thickness plates in a single pass with higher efficiency. However, the unique key-holing processes due to the special constricted arc behaviors cause much different thermal cycles of the liquid metals as well as changed microstructures. SDSS 2507 with a thickness of 10 mm was joined by PAW to investigate the joints' microstructure and properties. Microstructure characterization reveals substantial differences in the content of austenite, ranging from 68.9% in weld metal (WM) to 32.1% in the heat-affected zone (HAZ). The oxide inclusions in the WM enhance the hardness of the welded joints, but provide the path for crack propagation to decrease its impact toughness. While complicated microstructure is found in HAZ forming ferrite and diverse austenite, such as grain boundary austenite (GBA), intragrain austenite (IGA), and Widmanstätten austenites (WA). A small amount of secondary austenite (γ2) and chromium nitride are also found in HAZ, and they significantly deteriorate its corrosion resistance. The grain boundary misorientation angle distribution of the austenite in WM is found to be dominated by the low angle boundaries (LABs). However, its content decreases from the WM to base metal (BM). Selective corrosion occurs in all samples, where ferrite is preferentially dissolved when the extrinsic voltage is low (<0.5 V) and austenite is preferentially dissolved when the extrinsic voltage is high (>0.5 V), indicating the different electrochemical activity of the two phases. |
| first_indexed | 2024-04-10T20:17:22Z |
| format | Article |
| id | doaj.art-0bea05e3a2f24608a4e51a90aeff2b96 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-04-10T20:17:22Z |
| publishDate | 2023-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-0bea05e3a2f24608a4e51a90aeff2b962023-01-26T04:45:30ZengElsevierJournal of Materials Research and Technology2238-78542023-01-0122355374Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc weldingQi Wang0Guochao Gu1Chuanbao Jia2Kan Li3Chuansong Wu4MOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China; Shandong University-Weihai Research Institute of Industrial Technology, Shandong University, Weihai, 264209, ChinaMOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaMOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China; Shandong University-Weihai Research Institute of Industrial Technology, Shandong University, Weihai, 264209, China; Corresponding author. MOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China,MOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaMOE Key Lab for Liquid–Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaKeyhole plasma arc welding (PAW) of the super duplex stainless steel (SDSS) is expected to achieve full-penetration joints of medium-thickness plates in a single pass with higher efficiency. However, the unique key-holing processes due to the special constricted arc behaviors cause much different thermal cycles of the liquid metals as well as changed microstructures. SDSS 2507 with a thickness of 10 mm was joined by PAW to investigate the joints' microstructure and properties. Microstructure characterization reveals substantial differences in the content of austenite, ranging from 68.9% in weld metal (WM) to 32.1% in the heat-affected zone (HAZ). The oxide inclusions in the WM enhance the hardness of the welded joints, but provide the path for crack propagation to decrease its impact toughness. While complicated microstructure is found in HAZ forming ferrite and diverse austenite, such as grain boundary austenite (GBA), intragrain austenite (IGA), and Widmanstätten austenites (WA). A small amount of secondary austenite (γ2) and chromium nitride are also found in HAZ, and they significantly deteriorate its corrosion resistance. The grain boundary misorientation angle distribution of the austenite in WM is found to be dominated by the low angle boundaries (LABs). However, its content decreases from the WM to base metal (BM). Selective corrosion occurs in all samples, where ferrite is preferentially dissolved when the extrinsic voltage is low (<0.5 V) and austenite is preferentially dissolved when the extrinsic voltage is high (>0.5 V), indicating the different electrochemical activity of the two phases.http://www.sciencedirect.com/science/article/pii/S2238785422018129Plasma arc weldingSuper duplex stainless steelMicrostructure evolutionMechanical propertiesCorrosion performance |
| spellingShingle | Qi Wang Guochao Gu Chuanbao Jia Kan Li Chuansong Wu Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding Journal of Materials Research and Technology Plasma arc welding Super duplex stainless steel Microstructure evolution Mechanical properties Corrosion performance |
| title | Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| title_full | Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| title_fullStr | Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| title_full_unstemmed | Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| title_short | Investigation of microstructure evolution, mechanical and corrosion properties of SAF 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| title_sort | investigation of microstructure evolution mechanical and corrosion properties of saf 2507 super duplex stainless steel joints by keyhole plasma arc welding |
| topic | Plasma arc welding Super duplex stainless steel Microstructure evolution Mechanical properties Corrosion performance |
| url | http://www.sciencedirect.com/science/article/pii/S2238785422018129 |
| work_keys_str_mv | AT qiwang investigationofmicrostructureevolutionmechanicalandcorrosionpropertiesofsaf2507superduplexstainlesssteeljointsbykeyholeplasmaarcwelding AT guochaogu investigationofmicrostructureevolutionmechanicalandcorrosionpropertiesofsaf2507superduplexstainlesssteeljointsbykeyholeplasmaarcwelding AT chuanbaojia investigationofmicrostructureevolutionmechanicalandcorrosionpropertiesofsaf2507superduplexstainlesssteeljointsbykeyholeplasmaarcwelding AT kanli investigationofmicrostructureevolutionmechanicalandcorrosionpropertiesofsaf2507superduplexstainlesssteeljointsbykeyholeplasmaarcwelding AT chuansongwu investigationofmicrostructureevolutionmechanicalandcorrosionpropertiesofsaf2507superduplexstainlesssteeljointsbykeyholeplasmaarcwelding |