Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel
In this paper, the influence of the silicon (Si) content on microstructure and impact property of submerged arc weld metals (WMs) for weathering bridge steel was clarified. Actual submerged arc welding (SAW) was carried out to produce WMs with 0.18 wt.%, 0.36 wt.%, 0.51 wt.%, and 0.60 wt.% of Si. Th...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-08-01
|
| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/13/9/1506 |
| _version_ | 1797578886435831808 |
|---|---|
| author | Fangmin Li Bing Hu Qiuming Wang Liyang Zhao Yuzhu Yi Jinjian Li Qingfeng Wang |
| author_facet | Fangmin Li Bing Hu Qiuming Wang Liyang Zhao Yuzhu Yi Jinjian Li Qingfeng Wang |
| author_sort | Fangmin Li |
| collection | DOAJ |
| description | In this paper, the influence of the silicon (Si) content on microstructure and impact property of submerged arc weld metals (WMs) for weathering bridge steel was clarified. Actual submerged arc welding (SAW) was carried out to produce WMs with 0.18 wt.%, 0.36 wt.%, 0.51 wt.%, and 0.60 wt.% of Si. The low temperature impact property of weld metal was detected, and the weld microstructures were characterized by optical microscopy (OM), scanning and transmission electron microscope (SEM and TEM), and electron backscatter diffraction (EBSD). The results indicate that WMs consist of polygon ferrite (PF), acicular ferrite (AF), granular bainitic ferrite (GBF), and martensite/austenite (M/A) constituents in each Si content. With increasing Si, the proportion of PF increased, while AF and GBF coarsened, the area fraction, <i>f</i><sub>M/A</sub>, and the mean size, d<sub>M/A</sub>, of M/A constituents increased, the number of inclusions decreased, but the size increased. Further, the fraction of high-angle grain boundaries (HAGBs) with the misorientation tolerance angles (MTAs) greater than 15° reduced, while the mean equivalent diameter, MED<sub>MTA≥15°</sub>, of ferrite grains with HAGBs increased. Accordingly, the impact toughness of WM was degraded from 108.1 J to 39.4 J with the increase in Si. The increase in M/A constituents and inclusions size reduced the critical fracture stress, thereby formation of larger microcracks and cleavage planes occurred. The reduced HAGBs exhibited a low hindering effect on crack propagation, and, consequently, the impact toughness decreased with increasing Si content. |
| first_indexed | 2024-03-10T22:28:00Z |
| format | Article |
| id | doaj.art-74cce64164f949b59d8522ec1f7bbf11 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T22:28:00Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-74cce64164f949b59d8522ec1f7bbf112023-11-19T11:55:54ZengMDPI AGMetals2075-47012023-08-01139150610.3390/met13091506Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge SteelFangmin Li0Bing Hu1Qiuming Wang2Liyang Zhao3Yuzhu Yi4Jinjian Li5Qingfeng Wang6State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaState Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, ChinaIn this paper, the influence of the silicon (Si) content on microstructure and impact property of submerged arc weld metals (WMs) for weathering bridge steel was clarified. Actual submerged arc welding (SAW) was carried out to produce WMs with 0.18 wt.%, 0.36 wt.%, 0.51 wt.%, and 0.60 wt.% of Si. The low temperature impact property of weld metal was detected, and the weld microstructures were characterized by optical microscopy (OM), scanning and transmission electron microscope (SEM and TEM), and electron backscatter diffraction (EBSD). The results indicate that WMs consist of polygon ferrite (PF), acicular ferrite (AF), granular bainitic ferrite (GBF), and martensite/austenite (M/A) constituents in each Si content. With increasing Si, the proportion of PF increased, while AF and GBF coarsened, the area fraction, <i>f</i><sub>M/A</sub>, and the mean size, d<sub>M/A</sub>, of M/A constituents increased, the number of inclusions decreased, but the size increased. Further, the fraction of high-angle grain boundaries (HAGBs) with the misorientation tolerance angles (MTAs) greater than 15° reduced, while the mean equivalent diameter, MED<sub>MTA≥15°</sub>, of ferrite grains with HAGBs increased. Accordingly, the impact toughness of WM was degraded from 108.1 J to 39.4 J with the increase in Si. The increase in M/A constituents and inclusions size reduced the critical fracture stress, thereby formation of larger microcracks and cleavage planes occurred. The reduced HAGBs exhibited a low hindering effect on crack propagation, and, consequently, the impact toughness decreased with increasing Si content.https://www.mdpi.com/2075-4701/13/9/1506weathering bridge steelSi contentsubmerged arc weld metalM/A constituentsinclusionsimpact toughness |
| spellingShingle | Fangmin Li Bing Hu Qiuming Wang Liyang Zhao Yuzhu Yi Jinjian Li Qingfeng Wang Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel Metals weathering bridge steel Si content submerged arc weld metal M/A constituents inclusions impact toughness |
| title | Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel |
| title_full | Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel |
| title_fullStr | Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel |
| title_full_unstemmed | Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel |
| title_short | Evolutions of Microstructure and Impact Toughness of Submerged Arc Weld Metal via Introducing Varied Si for Weathering Bridge Steel |
| title_sort | evolutions of microstructure and impact toughness of submerged arc weld metal via introducing varied si for weathering bridge steel |
| topic | weathering bridge steel Si content submerged arc weld metal M/A constituents inclusions impact toughness |
| url | https://www.mdpi.com/2075-4701/13/9/1506 |
| work_keys_str_mv | AT fangminli evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT binghu evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT qiumingwang evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT liyangzhao evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT yuzhuyi evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT jinjianli evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel AT qingfengwang evolutionsofmicrostructureandimpacttoughnessofsubmergedarcweldmetalviaintroducingvariedsiforweatheringbridgesteel |