Stress state at the root of variable-wall-thickness pipeline welded joint

Guo, Baichen; Zhu, Yiyao; Dai, Lianshuang; Deng, Caiyan; Peng, Haodong; Wang, Dongpo; Liang, Hang

doi:10.1016/j.ijpvp.2022.104785

Cited by 10 publications

(3 citation statements)

References 24 publications

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“…Furthermore, more than 20 sets of full-size resonant bending fatigue tests were performed. In general, the reported research results indicate that the girth joint of an SCR has the worst fatigue performance of the entire flexible system, and the reduction in fatigue life is mainly attributed to microstructural inhomogeneity, [10][11][12] stress concentration, [13][14][15][16] welding residual stress, 17,18 and welding defects. 19,20 Generally, the significant microstructural inhomogeneity, higher local stress concentration coefficient, high-value welding residual stress, and the welding defect can severely reduce the fatigue life.…”

Section: Introductionmentioning

confidence: 99%

Fatigue testing strategies for the X65 steel catenary riser with small‐scale specimens considering the effect of welding residual stress

Zhang,

Deng,

Liang

et al. 2024

Fatigue Fract Eng Mat Struct

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To accurately evaluate the fatigue performance of a full‐scale deep‐water steel catenary riser (SCR) using small‐size specimens, six fatigue testing strategies were explored, considering the effect of welding residual stress. Through a comparison with the full‐scale resonant bending fatigue testing results, the most equivalent strategy using small‐scale specimens was identified. The results indicate that the test strategies applying constant stress underestimated the fatigue life, compared with that of a full‐scale specimen; meanwhile, fatigue life values obtained from the low‐stress ratio testing strategy were higher, particularly in the low‐stress range region. Comparatively, the fatigue lives obtained for the 100 mm‐wide specimens without cutting were higher in the high‐stress range region. The variable‐applied mean stress strategy using the 25 mm‐wide welded joint specimen was the most suitable for equivalence with the full‐scale fatigue testing, with only a 9.7% difference in the fatigue life testing results. The difference between the applied mean stress and the actual transverse welding residual stress under various fatigue testing strategies is the key factor affecting the equivalence of the fatigue testing results.

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Section: Introductionmentioning

confidence: 99%

Fatigue testing strategies for the X65 steel catenary riser with small‐scale specimens considering the effect of welding residual stress

Zhang,

Deng,

Liang

et al. 2024

Fatigue Fract Eng Mat Struct

Self Cite

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“…Root-cause failure analysis (RCFA) is an element of technical method that contributes to unveiling the primary failure of a component fails in advance and acquiring its corresponding damage mechanism. It links to the limitation of material to cope with multiple geological conditions and the threat from the environment where the pipeline is laying, especially in offshore environments [ 10 ]. Few studies have focused on the benefit of RCFA to determine the source of failure and a series of practical solutions correlated to improvement methods to hinder repetitive CO 2 corrosion [ [11] , [12] , [13] ].…”

Section: Introductionmentioning

confidence: 99%

Integrating the root cause analysis to machine learning interpretation for predicting future failure

Aditiyawarman

Soedarsono

Kaban

et al. 2023

Heliyon

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“…Carbon steel and low alloy steels are usually used for fabricating pressure vessels and boilers due to their excellent properties, such as strength and ability to withstand corrosion and high temperatures. However, the final selection of materials for constructing pressure vessels and boilers depends on the specific requirements of the intended use and the design specifications of the equipment [1][2][3][4][5][6][7]. Boiler components that come into contact with steam and hot water are exposed to severe operating conditions, including high pressure, temperature, and harsh environmental conditions.…”

Section: Introductionmentioning

confidence: 99%

Failure Analysis of Welded Steam Boiler Flange

Abdel-Aleem

Khodir

Newishy

2023

International Journal of Materials Technology and Innovation

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Steam boiler flange, made of steel ASTM A105 welded to spool pipe, experienced a failure near the welding area after six years of service. The operator company has reported that a sudden increase in operating pressure and temperature exceeded the normal operation conditions. As a result, the failed flange and welded spool pipe segments were received for further investigation using root cause analysis to determine the reason for the failure. The failed parts were visually inspected (VT) and tested for subsurface defects with a fluorescent wet magnetic particle test (MT). Chemical analysis, microstructure observations, and hardness tests are conducted for the failed flange and pipe. It is noticed that there were no abnormalities or indications of creep or overheating were found in the microstructure and hardness values. Upon examining the macro & microstructure of the connecting weld joint, several welding defects, such as non-metallic inclusions, few porosities, and lack of fusion between welded passes, were noticed. Scanning Electron Microscope (SEM) observations showed that fine striations as beach marks on the fractured surface provided strong evidence of fatigue failure. The identified crack originated from welding defects and progressed through the flange material due to fluctuating radial stresses due to the cyclic changes in working pressure during service. To prevent similar failures, it is recommended to apply proper welding procedure specifications (WPS) by qualified welders, conduct regular inspections and maintenance of the steam boiler, and keep working conditions stable.

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Stress state at the root of variable-wall-thickness pipeline welded joint

Cited by 10 publications

References 24 publications

Fatigue testing strategies for the X65 steel catenary riser with small‐scale specimens considering the effect of welding residual stress

Fatigue testing strategies for the X65 steel catenary riser with small‐scale specimens considering the effect of welding residual stress

Integrating the root cause analysis to machine learning interpretation for predicting future failure

Failure Analysis of Welded Steam Boiler Flange

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