ZHANG Si, ZHOU Mingjiang, LIANG Yuheng, et al. Phase transformation and flow simulation of weld pools at the crack tips of elbows under pulsed current[J]. Oil & Gas Storage and Transportation, 2025, 44(5): 1−12.
Citation: ZHANG Si, ZHOU Mingjiang, LIANG Yuheng, et al. Phase transformation and flow simulation of weld pools at the crack tips of elbows under pulsed current[J]. Oil & Gas Storage and Transportation, 2025, 44(5): 1−12.

Phase transformation and flow simulation of weld pools at the crack tips of elbows under pulsed current

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  • Received Date: July 10, 2024
  • Revised Date: August 16, 2024
  • Available Online: March 30, 2025
  • Objective In the base metal repair for elbows using pulsed currents, detour flow typically occurs at the crack tips, resulting in the formation of weld pools due to local temperature increases. The size, flow, and solidification behaviors of these weld pools, has a decisive effect on crack healing. Exploring the evolution patterns of weld pools near elbow cracks under the influence of pulsed currents, along with a further investigation into the healing mechanisms of crack tips and fronts, holds significant importance for the technological advancement of pipe crack repair utilizing pulsed currents.
    Methods A finite element model for repairing 90° high-pressure elbows with cracks using pulsed currents was established, based on Comsol software, focusing on NiCr21Mo high-pressure elbows with cracks. This model incorporated a multi-physical field coupling approach that combines “two-phase flow and phase field” within an “electrical-thermal-structural” three-field coupling framework. This integration allows for the simulation of phase transformation and the flow of weld pools. Further analysis explored the evolution patterns of weld pools near cracks in elbows during pulsed current discharge, as well as the phase transformation patterns and flow characteristics of the liquid-phase metal after halting the discharge.
    Results Both the duration and interval of pulse discharge were identified to be influential to the formation of molten pools associated with cracks.With a pulsed current density set at 2.4×108 A/m2, weld pools formed at the crack tips and fronts in U-shaped columns following current discharge exceeding 0.65 seconds. Beginning at 0.75 seconds of discharge, the melting effect extended from the regions around the cracks into the surrounding areas, and partial evaporation of the liquid-phase metal occurred, both of which are detrimental to crack healing. After the discharge was halted, the metal flow of the weld pools gradually slowed down, with crack healing efficiency peaking within the first 0.001 seconds, followed by complete solidification within 0.008 seconds. Consequently, a pulse interval greater than 0.008 seconds was identified as optimal to prevent adverse effects on the weld pool area during subsequent pulses, thereby enhancing repair performance.
    Conclusion The application of pulsed currents results in the formation of U-shaped columnar weld pools at the crack tip, with an increasing volume of liquid-phase material near the cracks as discharge time progresses. To maximize repair effectiveness, it is essential to select an appropriate discharge duration that allows for sufficient phase transformation at the crack tips and fronts, resulting in the formation of weld pools while avoiding solid-liquid phase transitions in surrounding areas. Additionally, the pulse discharge interval should be longer than the solidification time of the liquid metal in the weld pools. Otherwise, repair efficiency may decrease due to smaller weld pool sizes. It is advisable to determine the pulse discharge power, duration, and interval through simulations prior to repairing microcracks in high-pressure elbows using pulsed currents, thereby improving both the accuracy and efficiency of actual elbow crack repairs. (20 Figures, 2 Tables, 22 References)
  • [1]
    张继信,康健,樊建春,高建村. 高压弯管冲蚀失效分析及数值模拟[J]. 润滑与密封,2016,41(10):40−46. DOI: 10.3969/j.issn.0254-0150.2016.10.008.

    ZHANG J X, KANG J, FAN J C, GAO J C. Failure analysis and numerical simulation of high pressure elbow erosion wear[J]. Lubrication Engineering, 2016, 41(10): 40−46. doi: 10.3969/j.issn.0254-0150.2016.10.008
    [2]
    段有福. 高压弯头裂纹缺陷的超声波检测[D]. 西安:西安石油大学,2015.

    DUAN Y F. Ultrasonic detection of high pressure bend crack[D]. Xi’an: Xi’an Shiyou University, 2015.
    [3]
    余南平,王德恒. 中国制造2025[M]. 上海:上海人民出版社,2017:101-103.

    YU N P, WANG D H. Made in China 2025[M]. Shanghai: Shanghai People's Publishing House, 2017: 101-103.
    [4]
    李兵,黎宗琪,张杰,张昌红. 页岩气加砂压裂高压管汇失效爆裂风险控制措施研究与实践[J]. 安全,2019,40(5):15−18. DOI: 10.19737/j.cnki.issn1002-3631.2019.05.004.

    LI B, LI Z Q, ZHANG J, ZHANG C H. Research and practice on risk control measures of high-pressure manifold failure and burst during fracturing in shale gas field[J]. Safety & Security, 2019, 40(5): 15−18. doi: 10.19737/j.cnki.issn1002-3631.2019.05.004
    [5]
    徐滨士,夏丹,谭君洋,董世运. 中国智能再制造的现状与发展[J]. 中国表面工程,2018,31(5):1−13. DOI: 10.11933/j.issn.1007-9289.20180516001.

    XU B S, XIA D, TAN J Y, DONG S Y. Status and development of intelligent remanufacturing in China[J]. China Surface Engineering, 2018, 31(5): 1−13. doi: 10.11933/j.issn.1007-9289.20180516001
    [6]
    QIN R S, SU S X. Thermodynamics of crack healing under electropulsing[J]. Journal of Materials Research, 2002, 17(8): 2048−2052. DOI: 10.1557/JMR.2002.0303.
    [7]
    张萌. 含损伤镁合金力学性能脉冲电流调控及机理研究[D]. 长春:吉林大学,2023.

    ZHANG M. Research on modification and mechanism of mechanical properties of damaged magnesium alloy treated by the pulse current[D]. Changchun: Jilin University, 2023.
    [8]
    YU H L, LIU X H, LI X W, GODBOLE A. Crack healing in a low-carbon steel under hot plastic deformation[J]. Metallurgical and Materials Transactions A, 2014, 45(2): 1001−1009. DOI: 10.1007/s11661-013-2049-4.
    [9]
    曹凤雷,毛亚宁,汪殿龙,王立伟,梁志敏. 金属材料裂纹电脉冲修复研究进展[J]. 热加工工艺,2023,52(22):1−5,10. DOI: 10.14158/j.cnki.1001-3814.20220925.

    CAO F L, MAO Y N, WANG D L, WANG L W, LIANG Z M. Research progress of cracks repairing with pulsed current in metal materials[J]. Hot Working Technology, 2023, 52(22): 1−5,10. doi: 10.14158/j.cnki.1001-3814.20220925
    [10]
    SONG H, WANG Z J, HE X D, DUAN J. Self-healing of damage inside metals triggered by electropulsing stimuli[J]. Scientific Reports, 2017, 7(1): 7097. DOI: 10.1038/s41598-017-06635-9.
    [11]
    邓德伟,于涛,张林,杨树华,张洪潮. 脉冲电流-激光复合愈合钛合金深层裂纹微观组织研究[J]. 机械工程学报,2017,53(20):38−44. DOI: 10.3901/JME.2017.20.038.

    DENG D W, YU T, ZHANG L, YANG S H, ZHANG H C. Effect of healing on microstructure by the combined treatment of pulse current and laser applied to deep crack in titanium alloy[J]. Journal of Mechanical Engineering, 2017, 53(20): 38−44. doi: 10.3901/JME.2017.20.038
    [12]
    白象忠,付宇明,高殿全,王丽荣. 低合金模具钢脉冲放电止裂的宏微观分析[J]. 模具工业,2001(8):43−46. DOI: 10.3969/j.issn.1001-2168.2001.08.018.

    BAI X Z, FU Y M, GAO D Q, WANG L R. The macro and micro analysis of the crack restraint by pulse discharge for low-alloy die steel[J]. Die & Mould Industry, 2001(8): 43−46. doi: 10.3969/j.issn.1001-2168.2001.08.018
    [13]
    杨川. 金属管件微裂纹的电涡流修复方法及机理研究[D]. 哈尔滨:哈尔滨工业大学,2019.

    YANG C. Eddy current treatment method and mechanics research on microcrack healing in the metal tubes[D]. Harbin: Harbin Institute of Technology, 2019.
    [14]
    梁玉恒,张思,占凯,徐昊. 脉冲电流修复高压管汇弯头裂纹有限元模拟[J]. 油气储运,2023,42(4):422−429. DOI: 10.6047/j.issn.1000-8241.2023.04.007.

    LIANG Y H, ZHANG S, ZHAN K, XU H. Finite element simulation on crack repair of high pressure manifold elbow by pulse current[J]. Oil & Gas Storage and Transportation, 2023, 42(4): 422−429. doi: 10.6047/j.issn.1000-8241.2023.04.007
    [15]
    LI Y Z, SU H T, JI H J, CHENG W Y. Numerical simulation to determine the gas explosion risk in longwall goaf areas: a case study of Xutuan Colliery[J]. International Journal of Mining Science and Technology, 2020, 30(6): 875−882. DOI: 10.1016/j.ijmst.2020.07.007.
    [16]
    雷洪. 不可压缩流体的数学和物理解析[J]. 中国冶金教育,2021(1):9−11. DOI: 10.16312/j.cnki.cn11-3775/g4.2021.01.004.

    LEI H. Mathematical and physical analysis of incompressible fluid[J]. China Metallurgical Education, 2021(1): 9−11. doi: 10.16312/j.cnki.cn11-3775/g4.2021.01.004
    [17]
    YANG X H, WANG W B, YANG C, JIN L W, LU T J. Solidification of fluid saturated in open-cell metallic foams with graded morphologies[J]. International Journal of Heat and Mass Transfer, 2016, 98: 60−69. DOI: 10.1016/j.ijheatmasstransfer.2016.03.023.
    [18]
    郭登明,吴海锋,郭建东,宁佳君,薛钢. 用于超高压管汇材料15CrNiMo的综合性能研究[J]. 石油机械,2019,47(4):104−109. DOI: 10.16082/j.cnki.issn.1001-4578.2019.04.017.

    GUO D M, WU H F, GUO J D, NING J J, XUE G. Comprehensive performance study of 15CrNiMo for ultra-high pressure manifold material[J]. China Petroleum Machinery, 2019, 47(4): 104−109. doi: 10.16082/j.cnki.issn.1001-4578.2019.04.017
    [19]
    张菽浪,张红斌. Incoloy 825耐蚀合金[J]. 特钢技术,2005,10(3):64−66. DOI: 10.16683/j.cnki.issn1674-0971.2005.03.028.

    ZHANG S L, ZHANG H B. Corrosion resistant alloy Incoloy 825[J]. Special Steel Technology, 2005, 10(3): 64−66. doi: 10.16683/j.cnki.issn1674-0971.2005.03.028
    [20]
    于静. 基于强脉冲电流金属材料裂纹止裂及愈合技术研究[D]. 大连:大连理工大学,2014.

    YU J. Technology study on crack arrest and healing by high-density pulsed current[D]. Dalian: Dalian University of Technology, 2014.
    [21]
    白象忠,田振国,郑坚. 断裂力学中的电热效应[M]. 北京:国防工业出版社,2009:159-168.

    BAI X Z, TIAN Z G, ZHENG J. Electrothermal effect in fracture mechanics[M]. Beijing: National Defense University Press, 2009: 159-168.
    [22]
    FAN H G, KOVACEVIC R. Droplet formation, detachment, and impingement on the molten pool in gas metal arc welding[J]. Metallurgical and Materials Transactions B, 1999, 30(4): 791−801. DOI: 10.1007/s11663-999-0041-6.

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