涂层剥离条件下X70管线钢的应力腐蚀裂纹萌生行为
收稿日期: 2012-05-04
修回日期: 2012-06-02
网络出版日期: 2012-10-11
基金资助
国家自然科学基金项目51025104和辽宁省博士启动基金项目20101048资助
STRESS CORROSION CRACK INITIATION BEHAVIOR FOR THE X70 PIPELINE STEEL BENEATH A DISBONDED COATING
Received date: 2012-05-04
Revised date: 2012-06-02
Online published: 2012-10-11
Supported by
Supported by National Natural Science Foundation of China (No.51025104) and PhD Starting Funds of Liaoning Provincial Science and Technology Department (No.20101048)
通过循环载荷实验, 研究了管道涂层剥离条件下, 阴极保护电位对X70管线钢在近中性pH值溶液(NS4溶液)中应力腐蚀裂纹萌生的影响. 利用SEM观察了距涂层剥离口不同距离处的应力腐蚀裂纹的萌生情况.结果表明, 外加-850 mV阴极保护电位时, 剥离涂层下样品表面裂纹的萌生程度随距离涂层开裂口长度的增加而逐渐减轻; 外加-1000 mV阴极保护电位时,剥离涂层下样品表面裂纹的萌生程度随距离涂层开裂口长度的增加而稍有增加, 但缝隙内各个位置的裂纹萌生程度低于-850 mV极化电位下缝隙内部相应位置的裂纹萌生程度; 涂层的剥离降低了阴极保护的效果, 要达到涂层完整时的阴极保护效果, 则需要使阴极保护电位适当负移.
王志英 王俭秋 韩恩厚 柯伟 闫茂成 张峻巍 刘楚威 . 涂层剥离条件下X70管线钢的应力腐蚀裂纹萌生行为[J]. 金属学报, 2012 , 48(10) : 1267 -1272 . DOI: 10.3724/SP.J.1037.2012.00254
Stress corrosion cracking (SCC) has become one of the main threats for pipelines safe. The crack initiation is the first step for pipeline SCC. The disbonded coating affects the SCC initiation behavior. In the present paper, the effect of cathodic protection potential on SCC initiation for X70 pipeline steel in the NS4 solution beneath a disbonded coating is studied by a cyclic loading test. The SCC initiation situation was observed at the different distances beneath a disbonded coating area by SEM. The results show that the SCC initiation degree lightens with the increase of distance from the disbonded coating area under the condition of –850 mV cathodic protection potential. When the cathodic protection potential increases to –1000 mV, the SCC initiation degree slightly increases with the increase of distance from the disbonded position. But compared with that under the –850 mV, the crack initiation degree under –1000 mV is lower at the corresponding position. It is shown that the coating disbondment reduces the cathodic protection effect, and in order to obtain the same cathodic protection effect the cathodic protection potential should be appropriately moved in an negative way
Key words： pipeline steel; coating; stress corrosion cracking; crack initiation
[1] Yan M C, Wang J Q, Han E H. Corros Sci, 2008; 50: 1331
[2] Vuillemin B, Oltra R, Cottis R. Electrochim Acta, 2007; 52: 570
[3] Sridhar N, Dunn D S, Seth M. Corrosion, 2001; 57: 598
[4] Jack T R, Van Boven G, Wilmott M J, Utherby R L S,
Worthingham R G. Mater Perform, 1994; 33(8): 17
[5] Charles E A, Parkins R N. Corrosion, 1995; 51: 518
[6] Beavers J A, Thompson N G. Mater Perform, 1997; 36(4): 13
[7] Li Z F, Mao X H, Gan F X. J Chin Soc Corros Prot, 2000; 20: 3383
(李正复, 毛旭辉, 甘复兴. 中国腐蚀与防护学报, 2000; 20: 338)
[8] Li Z F, Mao X H, Gan F X. J Chin Soc Corros Prot, 2000; 20: 129
(李正复, 毛旭辉, 甘复兴. 中国腐蚀与防护学报, 2000; 20: 129)
[9] Chen X, Li X G, Du C W, Liang P. J Chin Soc Corros Prot, 2010; 30: 35
(陈旭, 李晓刚, 杜翠薇, 梁平. 中国腐蚀与防护学报, 2010; 30: 35)
[10] Song Y Q, Du C W, Zhang X, Li X G. Acta Metall Sin, 2009; 45: 1130
(宋义全, 杜翠薇, 张新, 李晓刚. 金属学报, 2009; 45: 1130)
[11] Guo H, Du C W, Li X G, Zhang X. Corros Sci Prot Technol, 2008; 20: 336
(郭昊, 杜翠薇, 李晓刚, 张新. 腐蚀科学与防护技术, 2008; 20: 336)
[12] Chen X, Li X G, Du C W, Liang P. Acta Metall Sin, 2008; 44: 1431
(陈旭, 李晓刚, 杜翠薇, 梁平. 金属学报, 2008; 44: 1431)
[13] Song Y Q, Du C W, Zhang X, Li X G. Acta Metall Sin, 2006; 42: 305
(宋义全, 杜翠薇, 张 新, 李晓刚. 金属学报, 2006; 42: 305)
[14] Chen X, Du CW, Li X G, Huang Y Z. J Appl Electrochem, 2009; 39: 697
[15] Li Z F, Gan F X, Mao X H. Corros Sci, 2002; 44: 689
[16] Yan M C. Postdoc Report, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 2007
(闫茂成. 中国科学院金属研究所博士后出站报告, 沈阳, 2007)
[17] Parkins R N. Corrosion’ 2000, Houston, Texas: NACE, 2000: Paper No. 00363(CD)
[18] Liu X, Yang W. Mater Mech Eng, 2002; 26(1): 5
(刘杏, 杨武. 机械工程材料, 2002; 26(1): 5)
[19] Charles E A, Parkins R N. Corrosion, 1995; 51: 518
[20] Yan M C, Wang J Q, Ke W, Han E H. J Chin Soc Corros Prot, 2007; 27: 257
(闫茂成, 王俭秋, 柯伟, 韩恩厚. 中国腐蚀与防护学报, 2007; 27: 257)
[21] Gu B, Luo J L, Mao X. Corrosion, 1999; 55: 96
[22] Qiao L J, Luo J L, Mao X. Corrosion, 1998; 54: 115
[23] Szb´c S, Bakos I. Corros Rew, 2006; 24: 39
[24] Niu L, Cheng Y F. Appl Surf Sci, 2007; 258: 8626
[25] Cheng Y F. Electrochim Acta, 2007; 52: 2661
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