CAJ | 학술논문

以西二线 X80管线钢为对象,采用动电位极化和交流阻抗技术研究了不同质量分数的Cl-和 SO 2-4在西二线清管产物模拟溶液中 X80钢内腐蚀行为,探讨了西二线管道内腐蚀机理。实验结果表明,X80管线钢在只含不同质量分数的 Cl-模拟溶液中的极化曲线都呈明显的活化控制,且随着Cl-质量分数的增大,X80钢的腐蚀电流密度 i corr 大幅增大,X80钢的腐蚀速率增大；X80在含质量分数为0.05%Cl-、不同质量分数的 SO 2-4模拟溶液中的极化曲线同样呈明显的活化控制,但是随着 SO 2-4质量分数的增大,X80钢的腐蚀速率呈现先增大后减小的趋势,SO 2-4质量分数为0.50%时,腐蚀电流密度 i corr 达到最大值,腐蚀最为严重；当模拟溶液中同时含有 Cl-和 SO 2-4时,X80钢的腐蚀电位与只含Cl-时相比均有所降低,腐蚀电流密度均增大；当 Cl-和 SO 2-4共存时,随着 SO 2-4质量分数的增加, SO 2-4能快速地吸附在金属表面,阻碍 Cl-的吸附,减小了 Cl-对金属的腐蚀。
이서이선 X80관선강위대상,채용동전위겁화화교류조항기술연구료불동질량분수적Cl-화 SO 2-4재서이선청관산물모의용액중 X80강내부식행위,탐토료서이선관도내부식궤리。실험결과표명,X80관선강재지함불동질량분수적 Cl-모의용액중적겁화곡선도정명현적활화공제,차수착Cl-질량분수적증대,X80강적부식전류밀도 i corr 대폭증대,X80강적부식속솔증대；X80재함질량분수위0.05%Cl-、불동질량분수적 SO 2-4모의용액중적겁화곡선동양정명현적활화공제,단시수착 SO 2-4질량분수적증대,X80강적부식속솔정현선증대후감소적추세,SO 2-4질량분수위0.50%시,부식전류밀도 i corr 체도최대치,부식최위엄중；당모의용액중동시함유 Cl-화 SO 2-4시,X80강적부식전위여지함Cl-시상비균유소강저,부식전류밀도균증대；당 Cl-화 SO 2-4공존시,수착 SO 2-4질량분수적증가, SO 2-4능쾌속지흡부재금속표면,조애 Cl-적흡부,감소료 Cl-대금속적부식。
Taking the X80 steel used in the second West-East Pipeline Project(WEPPⅡ)as a study object,this paper researched the effects of Cl- and SO 2 -4 with different concentration(wt%)on inter-nal corrosion behavior of X80 pipeline steel in stimulated solution for pigging product,discussed the internal corrosion mechanism of WEPPⅡby potentiodynamic polarization and electrochemical imped-ance spectroscopy (EIS)experimental.The results showed that,in the stimulated solution only con-taining different Cl- mass fraction,the polarization curves of X80 pipeline steel have typical character-istics of active dissolution,the corrosion current density(icorr)and the internal corrosion rate of X80 steel increases along with the increase of Cl- mass fraction;in the stimulated solution containing both 0.05% Cl- and different SO 2 -4 mass fraction,the polarization curves of X80 pipeline steel also have typical characteristics of active dissolution,but the internal corrosion rate firstly increases and then decreases with the increase of SO 2 -4 mass fraction.When the mass fraction of SO 2 -4 is 0.50%,the icorr reaches the maximum value while polarization resistance reaches the minimum value,and the corrosion behavior of X80 steel is the most serious at this time;when the stimulated solution contain both Cl- and SO 2 -4 ,the corrosion potential of X80 steel decreases while the icorr increases than the stimulated solution only containing Cl- ,with the increase of SO 2 -4 mass fraction;when the stimula-ted solution contain both Cl- and SO 2 -4 ,with the increase of SO 2 -4 mass fraction,SO 2 -4 can adsorb on the metal surface faster than Cl- ,which decreases the corrosion aroused by Cl- .