应力作用下X80钢焊接接头在近中性pH值溶液中的电化学行为研究
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摘要
管线钢近中性p H值环境应力腐蚀开裂(SCC)是管线失效的一种重要形式,但其发生机理仍不清楚,现场实际发现其易发生在焊缝附近。采用动电位极化和电化学阻抗技术研究了外加拉应力对X80钢焊接接头在近中性p H值溶液中电化学行为的影响。结果表明:应力使X80钢母材和焊缝的腐蚀电位负移,腐蚀电流密度增大,应力促进了母材和焊缝的阳极溶解和阴极反应;在弹性变形区间,外加应力没有破坏腐蚀产物膜的完整性,腐蚀产物膜电阻几乎不变,应力使腐蚀产物膜孔隙结构变大,促进侵蚀性离子向电极表面扩散,母材和焊缝的电荷转移电阻明显减小;由于组织结构的原因,焊缝的应力影响系数比母材的大,X80钢焊缝比母材有更强的应力敏感性。
The electrochemical behavior of X80 steel weld joint in solution with near-neutral p H value under the tensile stress was studied by potentiodynamic polarization and electrochemical impendence spectrum. Results showed that the tensile stress led to decreased corrosion potential of X80 base steel and increased corrosion current. Meanwhile,both of anode dissolution and cathode reactions of the substrate steel and weld joint were accelerated by tensile stress. When the stress in the range of elastic deformation,the tensile stress did not broke the corrosion production film,and the film resistance was almost unchanged. The stress enhanced the porous structure of corrosion production film,which promoted the corrosive ions spreading to the surface of electrode and reduced largely the charge transfer resistance of substrate steel and weld joint. Owing to the distribution of organization structure,the stress-influence coefficient of weld joint was higher than that of substrate steel,and the X80 steel weld joint possessed stronger stress sensitivity than the substrate.
The electrochemical behavior of X80 steel weld joint in solution with near-neutral p H value under the tensile stress was studied by potentiodynamic polarization and electrochemical impendence spectrum. Results showed that the tensile stress led to decreased corrosion potential of X80 base steel and increased corrosion current. Meanwhile,both of anode dissolution and cathode reactions of the substrate steel and weld joint were accelerated by tensile stress. When the stress in the range of elastic deformation,the tensile stress did not broke the corrosion production film,and the film resistance was almost unchanged. The stress enhanced the porous structure of corrosion production film,which promoted the corrosive ions spreading to the surface of electrode and reduced largely the charge transfer resistance of substrate steel and weld joint. Owing to the distribution of organization structure,the stress-influence coefficient of weld joint was higher than that of substrate steel,and the X80 steel weld joint possessed stronger stress sensitivity than the substrate.
引文
[1]BRUCHHAUSEN M,FISCHER B,RUIZ A,et al.Impact of hydrogen on the high cycle fatigue behaviour of Inconel718 in asymmetric push-pull mode at room temperature[J].Int J Fatigue,2015,70:137-145.
[2]ZHANG J W,WANG G Z,XUAN F Z,et al.Effect of stress dependent creep ductility on creep crack growth behaviour of steels for wide range of C[J].Mater High Temp,2015,32(4):369-376.
[3]SUN M,XIAO K,DONG C,et al.Effect of stress on electrochemical characteristics of pre-cracked ultrahigh strength stainless steel in acid sodium sulphate solution[J].Corros Sci,2014(24):137-145.
[4]ZHONG C,TANG X,CHENG Y F.Corrosion of steel under the defected coating studied by localized electrochemical impedance spectroscopy[J].Electrochim Acta,2008,53:4 740-4 747.
[5]YAN M,YANG S,SUN C,et al.Stress corrosion of pipeline steel under occluded coating disbondment in a red soil environment[J].Corros Sci,2015,93:27-38.
[6]郭浩,李光福,蔡珣,等.X70管线钢在不同温度近中性p H溶液中的应力腐蚀破裂行为[J].金属学报,2004,40(9):967-971.
[7]JIA Y Z,LI H,HU N N.Comparative assessment of nearneutral p H stress corrosion cracking resistance of pipeline steels with different strength[J].Mater&Corros,2015,66(11):1 250-1 255.
[8]KAMAYA M.A stress-based criterion for ductile crack ini-tiation of pre-strained carbon steel[J].Eng Fract Mech,2012,96:461-479.
[9]TANG X,CHENG Y F.Micro-electrochemical characterization of the effect of applied stress on local anodic dissolution behavior of pipeline steel under near-neutral p H condition[J].Electrochim Acta,2009,54(5):1 499-1 505.
[10]ZHANG G A,CHENG Y F.Micro-electrochemical characterization of corrosion of welded X70 pipeline steel in nearneutral p H solution[J].Corros Sci,2009,51(8):1 714-1 724.
[11]陈旭,何川,刘硕,等.应力对X70钢在Na HCO3溶液中腐蚀行为的影响[J].石油化工高等学校学报,2011,24(5):69-73.
[12]张杰,刘静,胡骞,等.拉应力对X80钢原始及水淬组织在酸性土壤中腐蚀电化学行为的影响[J].材料保护,2014,47(9):18-21.
[13]袁玮,黄胡,胡骞,等.外加拉应力对X80管线钢点蚀电化学行为的影响[J].中国腐蚀与防护学报,2013,33(4):227-283.
[14]XU L Y,CHENG Y F.An experimental investigation of corrosion of X100 pipeline steel under uniaxial elastic stress in a near-neutral p H solution[J].Corros Sci,2012,59:103-109.
[15]GOPI D,GOVINDARAJU K M,KAVITHA L.Synthesis,characterization and corrosion protection proterties of poly(N-vinylcarbazole-co-glycidyl methacrylate)coatings on low nickel stainless steel[J].Prog Org Coat,2011,71:11-18.
[16]谢飞,王丹,吴明,等.库尔勒土壤中溶解氧含量对X80钢及其焊缝腐蚀行为的影响[J].材料保护,2014,47(9):56-58.
[17]OHA B H,JANG S Y.Prediction of diffusivity of concrete based on simple analytic equations[J].Cement Concr Res,2004,34:463-480.
[18]ZHANG G A,CHENG Y F.Micro-electrochemical corrosion of welded X70 pipeline steel in near-neutral p H soltuion[J].Corros Sci,2009,51:171-172.
[19]李明星,王荣,白真权.X70管线钢在模拟近中性土壤介质中的电化学特性[J].腐蚀科学与防护技术,2004,16(1):17-20.
[2]ZHANG J W,WANG G Z,XUAN F Z,et al.Effect of stress dependent creep ductility on creep crack growth behaviour of steels for wide range of C[J].Mater High Temp,2015,32(4):369-376.
[3]SUN M,XIAO K,DONG C,et al.Effect of stress on electrochemical characteristics of pre-cracked ultrahigh strength stainless steel in acid sodium sulphate solution[J].Corros Sci,2014(24):137-145.
[4]ZHONG C,TANG X,CHENG Y F.Corrosion of steel under the defected coating studied by localized electrochemical impedance spectroscopy[J].Electrochim Acta,2008,53:4 740-4 747.
[5]YAN M,YANG S,SUN C,et al.Stress corrosion of pipeline steel under occluded coating disbondment in a red soil environment[J].Corros Sci,2015,93:27-38.
[6]郭浩,李光福,蔡珣,等.X70管线钢在不同温度近中性p H溶液中的应力腐蚀破裂行为[J].金属学报,2004,40(9):967-971.
[7]JIA Y Z,LI H,HU N N.Comparative assessment of nearneutral p H stress corrosion cracking resistance of pipeline steels with different strength[J].Mater&Corros,2015,66(11):1 250-1 255.
[8]KAMAYA M.A stress-based criterion for ductile crack ini-tiation of pre-strained carbon steel[J].Eng Fract Mech,2012,96:461-479.
[9]TANG X,CHENG Y F.Micro-electrochemical characterization of the effect of applied stress on local anodic dissolution behavior of pipeline steel under near-neutral p H condition[J].Electrochim Acta,2009,54(5):1 499-1 505.
[10]ZHANG G A,CHENG Y F.Micro-electrochemical characterization of corrosion of welded X70 pipeline steel in nearneutral p H solution[J].Corros Sci,2009,51(8):1 714-1 724.
[11]陈旭,何川,刘硕,等.应力对X70钢在Na HCO3溶液中腐蚀行为的影响[J].石油化工高等学校学报,2011,24(5):69-73.
[12]张杰,刘静,胡骞,等.拉应力对X80钢原始及水淬组织在酸性土壤中腐蚀电化学行为的影响[J].材料保护,2014,47(9):18-21.
[13]袁玮,黄胡,胡骞,等.外加拉应力对X80管线钢点蚀电化学行为的影响[J].中国腐蚀与防护学报,2013,33(4):227-283.
[14]XU L Y,CHENG Y F.An experimental investigation of corrosion of X100 pipeline steel under uniaxial elastic stress in a near-neutral p H solution[J].Corros Sci,2012,59:103-109.
[15]GOPI D,GOVINDARAJU K M,KAVITHA L.Synthesis,characterization and corrosion protection proterties of poly(N-vinylcarbazole-co-glycidyl methacrylate)coatings on low nickel stainless steel[J].Prog Org Coat,2011,71:11-18.
[16]谢飞,王丹,吴明,等.库尔勒土壤中溶解氧含量对X80钢及其焊缝腐蚀行为的影响[J].材料保护,2014,47(9):56-58.
[17]OHA B H,JANG S Y.Prediction of diffusivity of concrete based on simple analytic equations[J].Cement Concr Res,2004,34:463-480.
[18]ZHANG G A,CHENG Y F.Micro-electrochemical corrosion of welded X70 pipeline steel in near-neutral p H soltuion[J].Corros Sci,2009,51:171-172.
[19]李明星,王荣,白真权.X70管线钢在模拟近中性土壤介质中的电化学特性[J].腐蚀科学与防护技术,2004,16(1):17-20.