邓海英
中国腐蚀与防护学报
用动电位扫描法和交流阻抗法研究X70钢在饱和CO2的HAc-NaAc溶液中的腐蚀行为。结果表明：酸性溶液中存在CO2时，使得溶液中H+浓度增大，同时还有可还原的H2CO3、HCO3-，可加快X70钢的腐蚀。X70钢在HAc-NaAc溶液中活性溶解时生成的中间产物Fe(OH)ads，在饱和CO2的HAc-NaAc溶液中，活性溶解时生成的中间产物仍为Fe（OH）ads。
关键词:
酸性溶液
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acid solution
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CO2
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X70 steel
Zhiyong LIU
金属学报(英文版)
doi:10.1016/S1006-7191(08)60071-X
Stress corrosion cracking (SCC) of X70 pipeline steel in simulated solution of the acidic soil in Yingtan in China was investigated using slow strain rate test (SSRT), SEM and potentiodynamic polarization technique. Experiment results indicate that X70 steel is highly susceptible to SCC as applied potential reduces, which is manifested in loss of toughness and brittle fracture. Constant polarization current can detect the occurrence of SCC. The lower the polarization current is the sooner stress corrosion cracking occurs. The SCC mechanisms are different at varying potentials. When potential is higher than open circuit potential, anodic process controls SCC, whereas when potential is far lower than open circuit potential, cathodic process controls SCC, and between these two potential regions, a combined electrochemical process controls the SCC. Stress or strain has a synergistic effect with electrochemical reactions to accelerate the cathodic hydrogen evolution process, which makes the X70 pipeline steel to be more susceptible to SCC.
关键词:
X70 steel
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null
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null
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null
Junwei WU
,
Xiaogang LI
,
Cuiwei DU
,
Song WANG
,
Yiquan SONG
材料科学技术（英文）
Corrosion behaviors of X70 steel were studied by means of electrochemical experiments and morphology observation. First, through potentiodynamic polarization in solution of various Cl- ions concentration, it was found that Epit began to appear in solution of Cl¬- concentration above 0.1 mol/L, and there was a critical point of Cl- concentration between 0.05 mol/L and 0.1 mol/L, below which the extent of pitting and general corrosion were trivial, while in solution of Cl- concentration above 0.1 mol/L, general and pitting corrosion became greater as the increasing of Cl- concentration. All of them were confirmed by the SEM observations after anodic polarization. Second, via the potentiodynamic polarization curves of X70 steel in 0.5 mol/L Cl-solution with 0, 0.05, 0.5 and 1 mol/L SO¬42- ions, it was found SO¬42- ions were able to inhibit corrosion aroused from Cl-1 ions, accordingly a model was set up to describe the process. In addition, to further explore the inhibited effect of SO¬42- ions, EIS was used in solutions of different Cl- and SO¬42- concentrations, the results revealed that the electrochemical resistance has a relation with the [SO42-]/[Cl-], that was, the bigger the value of [SO42-]/[Cl-], the greater the electrochemical resistance.
关键词:
X70 steel
,
null
,
null
,
null
,
null
X Y He
,
H Y Deng
,
R Li
金属学报(英文版)
Corrosion monitoring techniques were performed on X70 steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5mg/L-25mg/L.It was found that when the concentration of the inhibitors were increased the inhibitor efficiencies ,IE.and IE of thiourea varied with solution temperature ,immersion time. The results indicated that thiourea had the highest inhibiton efficiency.The potentiondynamic polarization studies revealed that thiourea are mixed tye inhibitor that mainly restrain the anodic process.
关键词:
corrosion
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null
,
null
,
null
封子艳
,
杨志刚
,
南蓓蓓
,
魏彦林
,
李辉
,
崔铭伟
表面技术
doi:10.16490/j.cnki.issn.1001-3660.2016.08.013
目的 研究在多相流动状态,尤其是段塞流动条件下,各种浓度的不同缓蚀剂对X70钢腐蚀的影响.方法 采用自制实验装置模拟起伏管路段塞流动条件,通过电子显微镜、挂片失重等方法,对挂片表面形貌、腐蚀速率进行分析,数值仿真了多相流动状态下缓蚀剂乙二醇对X70钢CO2腐蚀速率的影响.结果 自制实验装置的挂片表面形貌、挂片失重速度与真实环道实验相似.实验用缓蚀剂的质量浓度超过35 mg/L后,均匀腐蚀缓蚀效率提升明显,继续提高缓蚀剂的浓度,均匀腐蚀缓蚀效率变化不大.多相流动条件下,缓蚀剂对局部腐蚀的缓蚀效果不明显.仿真用缓蚀剂乙二醇的质量浓度达到250 mg/L后,缓蚀效率变化与实验结果类似.结论 自制实验装置可以模拟起伏管路内气液两相流动状态,实验结果可靠.缓蚀剂的最佳缓蚀效率存在临界浓度,小于临界值时,对挂片的缓蚀作用甚微,超过临界浓度时对挂片表面的腐蚀速率影响不大.段塞流动状态下,缓蚀剂的缓蚀作用仅针对挂片均匀腐蚀,对局部腐蚀影响不大,甚至会促进局部腐蚀的发展.
关键词:
X70钢
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多相流
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CO2腐蚀
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缓蚀剂
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临界值
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实验
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数值仿真
张林
,
杜敏
,
刘吉飞
,
李妍
,
刘培林
材料科学与工艺
为探索X70钢最大阴极保护电位,采用电化学测试和慢应变速率实验（SSRT）并结合断口扫描电镜观察,研究了低温低溶解氧和常温海水中阴极极化电位对X70钢氢脆敏感性的影响.结果表明：相对常温海水,X70钢在低温低溶解氧海水中的析氢电位正移;随阴极极化电位的负移,X70钢的最大抗拉强度、屈服强度增加且氢脆敏感性增加;在低温低溶解氧海水中,当极化电位负于-1050 mV时（相对于饱和甘汞电极电位）,断口出现准解理断裂特征形貌;相同电位下,X70钢在低温低溶解氧海水中的氢脆敏感性低于常温海水.
关键词:
氢脆
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阴极极化
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低温低溶解氧
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慢应变拉伸
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X70钢
郝宏娜
,
李自力
,
王太源
,
杜松林
,
王帅华
腐蚀与防护
利用电化学阻抗测试技术等，研究了X70钢在滨海盐渍土与海水构成的宏电池中的腐蚀行为。结果表明，构成宏电池之后，海水侧X70钢一直作为宏电池的阳极处于被腐蚀状态，其腐蚀速率为自然腐蚀速率的25．3倍，腐蚀过程主要受阴极反应控制；由于腐蚀产物膜和氯离子的双重作用使宏电池腐蚀速率先有一定程度的降低，然后迅速升高，再有所降低并趋于稳定。试验还发现土壤海水构成的宏电池的电动势并没有表现出像常规土壤宏电池电动势那样的先升高后降低的趋势，而是先有一定程度的降低，然后迅速升高后趋于稳定，该过程主要受极化电阻的影响。
关键词:
宏电池腐蚀
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海水
,
盐渍土
,
X70钢
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电化学阻抗谱
