腐蚀与防护
腐蝕與防護
부식여방호
CORROSION & PROTECTION
2015年
4期
373-377
,共5页
朱成丽%李晓红%吴洪亮%叶建锋
硃成麗%李曉紅%吳洪亮%葉建鋒
주성려%리효홍%오홍량%협건봉
耐张线夹%错位型缺陷%腐蚀%仿真
耐張線夾%錯位型缺陷%腐蝕%倣真
내장선협%착위형결함%부식%방진
strain clamp%malposition type defect%corrosion%simulation
通过对输电线路压接金具错位型缺陷引发的失效案例进行调研,发现因耐张线夹铝管尾部与钢锚未压合致铝管内钢芯锈蚀引发的事故很多。针对两起线夹失效案例,结合宏观、脱锌与腐蚀坑检查等试验分析,和基于试验结果的仿真分析,研究了错位型缺陷及其引发的腐蚀对钢芯应力恶化、断裂的影响。结果表明,铝管尾部与钢锚未压合,钢管口钢芯应力为正常时的3.1倍,不足以使钢芯断裂。密封不良引发钢管口钢芯缝隙内腐蚀,产生蚀坑和裂纹,当蚀坑深度达到0.5 mm 时,蚀坑内最大应力为正常时的8.3倍,达到钢芯的抗拉极限。蚀坑的出现与扩展使得管口钢芯应力状态迅速恶化至断裂。研究结果对防范和诊断类似事故有着重要价值。
通過對輸電線路壓接金具錯位型缺陷引髮的失效案例進行調研,髮現因耐張線夾鋁管尾部與鋼錨未壓閤緻鋁管內鋼芯鏽蝕引髮的事故很多。針對兩起線夾失效案例,結閤宏觀、脫鋅與腐蝕坑檢查等試驗分析,和基于試驗結果的倣真分析,研究瞭錯位型缺陷及其引髮的腐蝕對鋼芯應力噁化、斷裂的影響。結果錶明,鋁管尾部與鋼錨未壓閤,鋼管口鋼芯應力為正常時的3.1倍,不足以使鋼芯斷裂。密封不良引髮鋼管口鋼芯縫隙內腐蝕,產生蝕坑和裂紋,噹蝕坑深度達到0.5 mm 時,蝕坑內最大應力為正常時的8.3倍,達到鋼芯的抗拉極限。蝕坑的齣現與擴展使得管口鋼芯應力狀態迅速噁化至斷裂。研究結果對防範和診斷類似事故有著重要價值。
통과대수전선로압접금구착위형결함인발적실효안례진행조연,발현인내장선협려관미부여강묘미압합치려관내강심수식인발적사고흔다。침대량기선협실효안례,결합굉관、탈자여부식갱검사등시험분석,화기우시험결과적방진분석,연구료착위형결함급기인발적부식대강심응력악화、단렬적영향。결과표명,려관미부여강묘미압합,강관구강심응력위정상시적3.1배,불족이사강심단렬。밀봉불량인발강관구강심봉극내부식,산생식갱화렬문,당식갱심도체도0.5 mm 시,식갱내최대응력위정상시적8.3배,체도강심적항랍겁한。식갱적출현여확전사득관구강심응력상태신속악화지단렬。연구결과대방범화진단유사사고유착중요개치。
Through the investigation on failure cases caused by malposition defects of transmission line compression fittings,it was found that large quantity of cases were caused by the defect that the tail of aluminum pipe wasn′t pressed against the steel anchor,which led to corrosion of steel cores in the aluminum pipe.The effects of malposition defects and related corrosion on stress worsening and core fracture were studied in dealing with two clamp failure cases,combined with experimental analyses and simulation analysis.The experimental analyses mentioned above included visual inspection and the check of dezincification and corrosion pits.The analyses indicated that when the tail of aluminum pipe was not forced against the steel anchor,the stress in steel cores on steel pipe orifice was 3.1 times as high as normal,and did not reach the breaking strength.However,bad seal resulted in the crevice corrosion of steel cores,leading to appearance of pits and cracks.When the depth of corrosion pits reached 0.5 mm,the maximum stress in the pits was 8.3 times as high as normal,reaching the tensile strength of steel cores.The appearance and expansion of pits worsened the stress state of steel cores till the cores broke.The research has great value in the precaution and diagnosis of similar failures.