Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding
Hydrogenation reactors are important oil-refining equipment that operate in high-temperature and high-pressure hydrogen environments and are commonly composed of 2.25Cr–1Mo–0.25V steel. For a hydrogenation reactor with a plate-welding structure, the processes and effects of welding residual stress (...
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MDPI AG
2020-09-01
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| Online Access: | https://www.mdpi.com/1996-1944/13/18/4126 |
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| author | Mu Qin Guangxu Cheng Qing Li Jianxiao Zhang |
| author_facet | Mu Qin Guangxu Cheng Qing Li Jianxiao Zhang |
| author_sort | Mu Qin |
| collection | DOAJ |
| description | Hydrogenation reactors are important oil-refining equipment that operate in high-temperature and high-pressure hydrogen environments and are commonly composed of 2.25Cr–1Mo–0.25V steel. For a hydrogenation reactor with a plate-welding structure, the processes and effects of welding residual stress (WRS) are very complicated due to the complexity of the welding structure. These complex welding residual stress distributions affect the service life of the equipment. This study investigates the evolution of welding residual stress during weld-overlay cladding for hydrogenation reactors using the finite element method (FEM). A blind hole method is applied to verify the proposed model. Unlike the classical model, WRS distribution in a cladding/substrate system in this study was found to be divided into three regions: the cladding layer, the stress-affected layer (SAL), and the substrate in this study. The SAL is defined as region coupling affected by the stresses of the cladding layer and substrate at the same time. The evolution of residual stress in these three regions was thoroughly analyzed in three steps with respect to the plastic-strain state of the SAL. Residual stress was rapidly generated in Stage 1, reaching about −440 MPa compression stress in the SAL region at the end of this stage after 2.5 s. After cooling for 154 s, at the end of Stage 2, the WRS distribution was fundamentally shaped except for in the cladding layer. The interface between the cladding layer and substrate is the most heavily damaged region due to the severe stress gradient and drastic change in WRS during the welding process. The effects of substrate thickness and preheat temperature were evaluated. The final WRS in the cladding layer first increased with the increase in substrate thickness, and then started to decline when substrate thickness reached a large-enough value. WRS magnitudes in the substrate and SAL decreased with the increase in preheat temperature and substrate thickness. Compressive WRS in the cladding layer, on the other hand, increased with the increase in preheat temperature. |
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| language | English |
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| spelling | doaj.art-ff0c85bcc60f41b180d4934119238c542023-11-20T14:00:46ZengMDPI AGMaterials1996-19442020-09-011318412610.3390/ma13184126Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip CladdingMu Qin0Guangxu Cheng1Qing Li2Jianxiao Zhang3School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaSchool of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaSchool of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaLanzhou LS Heavy Equipment CO., LTD, Lanzhou 730300, ChinaHydrogenation reactors are important oil-refining equipment that operate in high-temperature and high-pressure hydrogen environments and are commonly composed of 2.25Cr–1Mo–0.25V steel. For a hydrogenation reactor with a plate-welding structure, the processes and effects of welding residual stress (WRS) are very complicated due to the complexity of the welding structure. These complex welding residual stress distributions affect the service life of the equipment. This study investigates the evolution of welding residual stress during weld-overlay cladding for hydrogenation reactors using the finite element method (FEM). A blind hole method is applied to verify the proposed model. Unlike the classical model, WRS distribution in a cladding/substrate system in this study was found to be divided into three regions: the cladding layer, the stress-affected layer (SAL), and the substrate in this study. The SAL is defined as region coupling affected by the stresses of the cladding layer and substrate at the same time. The evolution of residual stress in these three regions was thoroughly analyzed in three steps with respect to the plastic-strain state of the SAL. Residual stress was rapidly generated in Stage 1, reaching about −440 MPa compression stress in the SAL region at the end of this stage after 2.5 s. After cooling for 154 s, at the end of Stage 2, the WRS distribution was fundamentally shaped except for in the cladding layer. The interface between the cladding layer and substrate is the most heavily damaged region due to the severe stress gradient and drastic change in WRS during the welding process. The effects of substrate thickness and preheat temperature were evaluated. The final WRS in the cladding layer first increased with the increase in substrate thickness, and then started to decline when substrate thickness reached a large-enough value. WRS magnitudes in the substrate and SAL decreased with the increase in preheat temperature and substrate thickness. Compressive WRS in the cladding layer, on the other hand, increased with the increase in preheat temperature.https://www.mdpi.com/1996-1944/13/18/4126finite element modelelectroslag strip claddingweldingresidual stress evolution |
| spellingShingle | Mu Qin Guangxu Cheng Qing Li Jianxiao Zhang Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding Materials finite element model electroslag strip cladding welding residual stress evolution |
| title | Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding |
| title_full | Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding |
| title_fullStr | Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding |
| title_full_unstemmed | Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding |
| title_short | Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding |
| title_sort | evolution of welding residual stresses within cladding and substrate during electroslag strip cladding |
| topic | finite element model electroslag strip cladding welding residual stress evolution |
| url | https://www.mdpi.com/1996-1944/13/18/4126 |
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