Effects of Magnetic Field and Hydrogen on Anodic Reactions and Pitting of Pipeline Steel in Weakly Caustic Solution
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摘要:
通过电化学测试及表面形貌观察,研究了磁场对有、无预充氢的X70管线钢在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中阳极溶解速率及点蚀的影响。结果表明：未充氢试样在试验溶液中的开路电位处于电位-pH图中的活性溶解区,充氢试样的自腐蚀电位比未充氢试样负移约20 mV；施加0.4 T磁场后电流密度峰值显著升高,电流密度峰值之后出现骤降的转折电位显著正移,延缓进入稳定钝态；在活性溶解区恒电位极化时,0.4 T磁场使得充氢电极与未充氢电极的电流密度均增大,导致极化后充氢电极表面出现明显的点蚀连片及水平方向两侧局部加速溶解现象；在过钝化区恒电位极化时施加磁场使充氢电极电流密度总体趋向增大。
Abstract:The effects of magnetic field on the anodic dissolution rate and pitting corrosion of X70 pipeline steel with and without pre-charged hydrogen in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution were studied by electrochemical test and surface morphology observation. The results show that in test solution, the open circuit potential of the non-hydrogen charged X70 (non-H) sample was in the active dissolution zone of the potential-pH diagram. The open circuit potential of the hydrogen charged X70 (H-X70) sample was about 20 mV more negative than that of non-H sample. After imposing a 0.4 T magnetic field, the peak current density significantly increased, and there was a significant positive shift in the transition potential of the sudden drop after the peak current density, delaying the transition to the stable passive state. When potentiostatically polarized in the active dissolution zone, a 0.4 T magnetic field increased the current density of both the H-X70 electrode and non-H electrode, resulting in obvious pitting corrosion on the surface and local accelerated dissolution on both sides in the horizontal direction of the polarized H-X70 electrode. Applying a magnetic field during potentiostatic polarization in the passivation zone generally increased the current density of H-X70 electrode.
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Keywords:
- pipeline steel /
- corrosion /
- magnetic field /
- anodic dissolution /
- pitting /
- hydrogen
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腐蚀是影响油气管线服役安全性的重要原因,管线钢的腐蚀失效常常以局部腐蚀形式出现[1-5]。电磁设备、高压输电线路、高速列车或者管道检测剩磁等产生的磁场都可能会对附近的管线钢腐蚀产生影响,研究管线钢在磁场环境中的腐蚀行为及其规律具有工程应用价值[6-11]。管线钢腐蚀过程往往伴随着腐蚀产生的氢原子在其表面的累积和渗入,阴极保护作用下涂层破损处基体表面也会出现局部氢含量增加,从而影响管线钢后续的腐蚀或者开裂行为。有关材料中的氢和磁场的单独作用对金属腐蚀行为的影响已有研究和报道[12-18],而关于磁场和材料中的氢共同作用下金属腐蚀的电极过程还有待深入研究。
笔者通过预充氢的方法得到含有固溶氢的管线钢电极,采用有、无磁场作用下的电化学测试及电极表面形貌观察方法,研究了磁场和氢的共同作用对管线钢在含氯离子的碳酸氢钠溶液中阳极反应和局部腐蚀的影响规律,为管线钢在特种环境中的服役性能和安全评价提供依据。
1. 试验
试验用材为30 mm厚X70管线钢板,其化学组成见表1。
表 1 X70管线钢化学成分Table 1. Chemical composition of X70 pipeline steel元素 C Si Mn P S Cr Ti Nb V Ni Cu Mo Fe 质量分数/% 0.05 0.24 1.6 0.01 0.001 0.26 0.015 0.043 0.003 0.01 0.02 0.002 余量 电化学测试采用三电极体系：工作电极为X70管线钢,尺寸为直径5 mm、高8 mm,除工作面以外用环氧树脂封装,测试工作面积为0.20 cm2；辅助电极为Pt电极,参比电极为饱和甘汞电极（SCE）。工作电极分为不充氢和预充氢电极2种。预充氢在含有0.5 g/L硫脲的0.5 mol/L硫酸溶液中进行,试样为阴极,铂电极为辅助电极,充氢电流密度为5.0 mA/cm2,在常温（20 ℃）环境中充氢30 min。如无特殊说明,文中的电位均相对于SCE。
阳极极化和恒电位测试溶液均为自然曝氧的0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液,选择该溶液模拟近中性溶液条件,溶液的pH约为8.3。在该溶液中管线钢的自腐蚀状态为活性溶解态,阳极极化曲线表现为典型的活化-钝化-点蚀区域特征,在特定电位下阳极极化后管线钢出现点蚀,有利于研究磁场对点蚀的影响。外加磁场采用电磁铁产生,磁场为水平方向并且与工作电极表面平行。动电位扫描极化曲线测试时,扫描速率为100 mV/min,扫描范围为自腐蚀电位至2.0 V,观察每隔300 s加、撤磁场后的电流密度响应。选择0.4 T磁场是因为该数值处于管道探伤后剩磁的强度范围,而且磁场的作用比较明显,容易判断。根据0 T与0.4 T下测得的阳极极化曲线选择特征区域的电位（-0.2,0.8,1.25,1.7 V）进行恒电位极化。选择特定的时间结束试验后,采用蔡司Smartzoom5型光学显微镜观察极化后的电极表面形貌。
2. 结果与讨论
2.1 阳极极化曲线及电极形貌
将预充氢的工作电极置于测试溶液中浸泡至开路电位稳定,如图1所示,与未充氢试样相比,充氢试样的初始电位下降幅度略大,稳定时的电位更负,由约-0.75 V负移至约-0.77 V。有、无充氢试样的自腐蚀电位都位于电位-pH图的活性溶解区[19]。
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图 1 在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中有、无充氢试样的自腐蚀电位随时间的变化Figure 1. Change of open circuit corrosion potential of the samples with and without hydrogen charging with time in 0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl solution图2为0 T与0.4 T下预充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中的阳极极化曲线,图3为动电位极化后的试样表面微观形貌,图3中亮白色区域为点蚀。结果表明,施加磁场后,试样表面点蚀坑数量显著增加。
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图 2 0 T与0.4 T磁场下充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中的阳极极化曲线Figure 2. Anodic polarization curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T and 0.4 T magnetic field![]()
图 3 0 T与0.4 T磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中极化后的表面形貌Figure 3. Surface morphology of hydrogen-charged samples after polarization in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T and 0.4 T magnetic field2.2 恒电位极化及电极形貌
如图4所示,在0 T和0.4 T恒稳磁场条件下-0.2 V恒电位极化时,充氢与未充氢试样的电流密度随时间的变化趋势不同；未充氢试样的初始电流密度在0~40 s内快速下降,随后下降速率减缓；而充氢试样的初始电流密度在0~200 s内快速下降,随后下降速率减缓。磁场使得充氢与未充氢试样的电流密度均增加。图5所示为充氢试样在-0.2 V恒电位极化时加、撤磁场条件下的电流密度响应,电流密度随试验时间延长呈下降趋势。初始状态为0 T时,施加磁场后充氢试样的电流密度下降趋势明显减缓,撤去磁场时电流密度明显减小；初始状态为0.4 T时,撤去磁场后充氢试样的电流密度显著减小,再次施加磁场电流密度有回到原轨迹的趋势。
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图 4 0 T与0.4 T恒稳磁场条件下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化时的电流密度-时间曲线Figure 4. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at -0.2 V potentiostatic polarization under 0 T and 0.4 T constant magnetic field conditions![]()
图 5 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化时的电流密度-时间曲线Figure 5. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at -0.2 V potentiostatic polarization under applying and removing magnetic field如图6所示：在0 T或0.4 T恒稳磁场条件下-0.2 V恒电位极化1 200 s后,0 T磁场下未充氢试样表面的点蚀分布较为均匀,可大致分为数量较多且尺寸较小的点蚀,以及尺寸较大、数量较少的连片点蚀,点蚀之外有较大的可见原始划痕的钝化区域；0 T磁场下充氢试样表面出现条带状点蚀,并出现显著的阳极溶解,未出现钝化区域。0.4 T磁场下,未充氢试样中部出现均匀分布的点蚀,而在电极水平方向两侧出现局部加速溶解,在点蚀之间存在钝化区；0.4 T磁场下充氢试样表面出现比0 T时更密集的条带状腐蚀,点蚀之外为活性溶解区,并且在电极水平方向两侧出现明显的局部加速溶解区域,不出现钝化区域。需要注意,-0.2 V不在图2极化曲线点蚀区,但在该电位下极化后电极出现点蚀,这是因为不同的极化历程对应不同的电极表面状态,因此在动电位扫描极化曲线中各个特征电位区间电极的腐蚀行为有可能与相同电位区间恒电位极化的结果有所不同。
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图 6 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化1 200 s后的表面形貌Figure 6. Surface morphology of hydrogen-charged and uncharged samples after -0.2 V potentiostatic polarization for 1 200 s in 0.10 mol/L 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field图7与图8为充氢及未充氢试样在0.8 V电位,不同磁场条件下的电流密度-时间曲线,此时电位处于阳极极化曲线的钝化区。由图7可知,在恒稳磁场下,未充氢试样处于钝化态,而充氢试样的电流密度在初始阶段呈现短暂的高值,之后随时间延长先上升后下降,此时0.4 T恒稳磁场对充氢试样的电流密度有较大影响：使得进入钝化区所需的极化时间延长,除暂态外的最大电流密度减小,对应的时间点延后。如图8所示,在加、撤磁场条件下,经过初始较大电流密度后,电流密度保持先上升后下降的趋势,加、撤磁场对该趋势的影响不明显。
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图 7 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中0.8 V恒电位极化时的电流密度-时间曲线Figure 7. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 0.8 V potentiostatic polarization under 0 T and 0.4 T magnetic field![]()
图 8 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中0.8 V恒电位极化时的电流密度-时间曲线Figure 8. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl Solution at 0.8 V potentiostatic polarization under applying and removing magnetic field如图9所示,在恒稳磁场,1.25 V恒电位极化时,未充氢试样的初始暂态阶段为较高电流密度,骤降后的电流密度随时间的延长呈先上升后下降的趋势,充氢试样除暂态外整体电流密度较低。磁场显著提高了未充氢试样的整体电流密度,磁场对充氢试样的电流密度的影响减弱。如图10所示,在1.25 V恒电位极化,加、撤磁场条件下,初始状态为0.4 T时,充氢试样的电流密度除暂态外先上升后下降的趋势较明显,整体电流密度比初始状态为0 T时的高,但加、撤磁场对充氢试样的电流密度的影响不明显。由图11可见：电极表面深色部分为点蚀,在恒稳磁场条件下1.25 V恒电位极化1 200 s后,初始状态为0.4 T时充氢与未充氢试样表面点蚀主要分布在水平方向两侧,且点蚀尺寸较大,而初始状态为0 T时电极表面的点蚀无明显集中分布区域；0.4 T下未充氢试样的点蚀尺寸较大,0 T下未充氢试样的点蚀数量多于充氢试样,但充氢试样表面活性溶解区域较大。
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图 9 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.25 V恒电位极化时的电流密度-时间曲线Figure 9. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.25 V potentiostatic polarization under 0 T and 0.4 T magnetic field![]()
图 10 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.25 V恒电位极化时的电流密度-时间曲线Figure 10. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl Solution at 1.25 V potentiostatic polarization under applying and removing magnetic field![]()
图 11 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.25 V恒电位极化1 200 s后的表面形貌Figure 11. Surface morphology of hydrogen-charged and uncharged samples after 1.25 V potentiostatic polarization for 1 200 s in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field图12与图13为充氢与未充氢试样在不同磁场条件下1.7 V恒电位极化后的结果,此时电位处于阳极极化曲线的过钝化区。由图12可见：在0.4 T和0 T恒稳磁场下,初始暂态电流密度较大,未充氢试样的电流密度随时间的延长呈先上升后下降的趋势,充氢试样的电流密度在0.4 T恒稳磁场下的变化趋势与之相同,但在0 T下不出现这种变化趋势,0.4 T磁场增大了充氢试样的整体电流密度。如图13所示,在加、撤磁场条件下,初始状态为0 T时,施加磁场后电流密度保持上升趋势,撤去磁场后电流密度明显下降,再次施加磁场电流密度由下降趋势转变为上升趋势；初始状态为0.4 T时,电流密度遵循先上升后下降的变化趋势,此时磁场的影响较弱。如图14所示：电极表面深色部分为点蚀；在恒稳磁场条件下1.7 V恒电位极化1 200 s后,0 T下未充氢试样表面点蚀无明显集中分布倾向,充氢试样表面蚀坑主要分布在上下边缘；0.4 T下充氢及未充氢试样表面点蚀分布均集中于水平方向两侧,且与0 T下的情况相比,出现点蚀尺寸增大的情况；0.4 T下未充氢试样表面较大点蚀的数量多于充氢试样,但充氢试样表面活性溶解区域增大,充氢试样在0.4 T下的点蚀区域增大。
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图 12 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.7 V恒电位极化时的电流密度-时间曲线Figure 12. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.7 V potentiostatic polarization under 0 T and 0.4 T magnetic field![]()
图 13 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.7 V恒电位极化时的电流密度-时间曲线Figure 13. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.7 V potentiostatic polarization under applying and removing magnetic field![]()
图 14 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.7 V恒电位极化1 200 s后的表面形貌Figure 14. Surface morphology of hydrogen-charged and uncharged samples after 1.7 V potentiostatic polarization for 1 200 s in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field2.3 讨论
在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中未充氢试样的自腐蚀电位约为-0.75 V,处于Fe-H2O体系电位-pH图中的活性溶解区域[19],充氢试样的自腐蚀电位负移约20 mV,仍然处于Fe-H2O体系电位-pH图中的活性溶解区域,但表现出更强的活性反应倾向。有、无充氢试样的开路电位差异可以来源于多个过程中的单一或者组合效应：试样中氢对表面膜的作用；试样中氢与溶液中离子反应的后续效应；试样中氢的氧化还原反应与金属氧化反应的耦合。除此以外,金属充氢后电子态的变化也会引起其热力学势的变化,导致开路电位发生变化[20]。充氢后管线钢在测试溶液中的开路电位变化与车轴钢在碳酸氢钠溶液中的开路电位变化情况类似。
对于0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中的预充氢X70管线钢,施加0.4 T磁场后,阳极极化曲线中的电流密度峰值显著增大,电流密度骤降时对应的电位显著正移,并且电极难以进入稳定钝化态。这是因为溶液中的氯离子、电极中的氢和外加的磁场都对电极形成稳定钝态有阻碍作用,在三者的协同破坏或阻碍作用下,电极达不到形成稳定钝态的条件而表现出高电位区的过钝化溶解状态。如图14所示,0.4 T下电极表面的点蚀数量比0 T下的多,且0.4 T下极化后电极左右两侧对称出现月牙状点蚀密集区并连成片状。电极表面形貌佐证了磁场对电极溶解的加速作用。
恒电位极化的电流密度-时间曲线表明,氢与磁场对各个电位下阳极反应的影响各有特点,这与特定电位对应的阳极反应类型与速率控制过程有关。预充氢X70管线钢恒电位极化测试结果表明：外加磁场增大了极化初始阶段的阳极电流密度,之后继续极化加、撤磁场时阳极电流密度的增大或减小与外加电位值有关,这与特定极化条件下电极的表面状态有关,比如均匀溶解状态、局部溶解或点蚀状态、析氧反应为主状态等都密切相关。在-0.2 V极化时：0 T下未充氢电极表面出现点蚀和钝化区,0.4 T下未充氢电极表面中部的点蚀分布比较均匀且钝化区面积小于0 T下；充氢电极表面出现明显的点蚀连片、活性溶解区以及水平方向两侧的局部加速溶解区,但不出现钝化区,0.4 T下的局部加速溶解比0 T下更加明显。-0.2 V下磁场增大阳极电流密度主要是通过加速开口型的点蚀、增大活性溶解区域实现的。在1.7 V下极化时0.4 T磁场下预充氢电极的电流密度总体高于0 T时,0.4 T磁场下极化后电极表面出现水平方向两侧的局部加速溶解区,并且点蚀区面积大于0 T磁场下。
磁场对电化学过程的影响可以基于磁场的洛伦兹力效应[17]和开尔文力效应来分析[18],其中洛伦兹力效应或称为磁流体动力学效应（MHD）是由磁场与移动的带电粒子之间的相互作用产生的。对于点蚀体系,与点蚀机理和点蚀形貌有关,磁场的作用主要通过微观MHD和宏观MHD来解释。微观MHD直接作用于各个界面,而宏观MHD可作用于点蚀内部和外部耦合体系。对于开口的点蚀,微观MHD的作用显著,而对于闭口型的点蚀宏观MHD的作用会比较显著,磁场的作用会导致开口型的点蚀加速,还有可能导致闭口型的点蚀减缓[21]。磁场对于点蚀形核过程作用机理比较复杂,与初始缺陷的形成机理和演化机制有关。
3. 结论
（1）在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中充氢X70钢的开路电位比未充氢试样低约20 mV,这归因于氢对材料的热力学状态的影响；动电位扫描阳极极化曲线测试结果表明,施加磁场后充氢试样的阳极极化曲线电流密度峰值比无磁场下的显著提高,电流密度骤降,电位显著正移,阻碍了电极进入稳定钝态的进程。
（2）在活性溶解区进行恒电位测试,施加磁场后充氢电极与未充氢电极的电流密度均增大,测试后的充氢电极表面出现明显的点蚀连片及水平方向两侧局部加速溶解；在过钝化区进行恒电位极化测试,施加磁场使充氢电极的电流密度总体趋向增大。
（3）磁场与氢对X70管线钢在弱碱性溶液中的阳极溶解和点蚀有协同加速作用。
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图 1 在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中有、无充氢试样的自腐蚀电位随时间的变化
Figure 1. Change of open circuit corrosion potential of the samples with and without hydrogen charging with time in 0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl solution
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图 2 0 T与0.4 T磁场下充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中的阳极极化曲线
Figure 2. Anodic polarization curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T and 0.4 T magnetic field
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图 3 0 T与0.4 T磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中极化后的表面形貌
Figure 3. Surface morphology of hydrogen-charged samples after polarization in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T and 0.4 T magnetic field
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图 4 0 T与0.4 T恒稳磁场条件下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化时的电流密度-时间曲线
Figure 4. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at -0.2 V potentiostatic polarization under 0 T and 0.4 T constant magnetic field conditions
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图 5 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化时的电流密度-时间曲线
Figure 5. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at -0.2 V potentiostatic polarization under applying and removing magnetic field
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图 6 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中-0.2 V恒电位极化1 200 s后的表面形貌
Figure 6. Surface morphology of hydrogen-charged and uncharged samples after -0.2 V potentiostatic polarization for 1 200 s in 0.10 mol/L 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field
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图 7 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中0.8 V恒电位极化时的电流密度-时间曲线
Figure 7. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 0.8 V potentiostatic polarization under 0 T and 0.4 T magnetic field
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图 8 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中0.8 V恒电位极化时的电流密度-时间曲线
Figure 8. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl Solution at 0.8 V potentiostatic polarization under applying and removing magnetic field
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图 9 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.25 V恒电位极化时的电流密度-时间曲线
Figure 9. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.25 V potentiostatic polarization under 0 T and 0.4 T magnetic field
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图 10 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.25 V恒电位极化时的电流密度-时间曲线
Figure 10. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl Solution at 1.25 V potentiostatic polarization under applying and removing magnetic field
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图 11 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.25 V恒电位极化1 200 s后的表面形貌
Figure 11. Surface morphology of hydrogen-charged and uncharged samples after 1.25 V potentiostatic polarization for 1 200 s in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field
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图 12 0 T与0.4 T恒稳磁场下充氢与未充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.7 V恒电位极化时的电流密度-时间曲线
Figure 12. Current density-time curves of hydrogen-charged and uncharged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.7 V potentiostatic polarization under 0 T and 0.4 T magnetic field
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图 13 加、撤磁场下充氢试样在0.03 mol/L NaHCO3+0.000 1 mol/L NaCl溶液中1.7 V恒电位极化时的电流密度-时间曲线
Figure 13. Current density-time curves of hydrogen-charged samples in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution at 1.7 V potentiostatic polarization under applying and removing magnetic field
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图 14 0 T与0.4 T时充氢与未充氢试样在0.03 mol/L NaHCO3+ 0.000 1 mol/L NaCl溶液中1.7 V恒电位极化1 200 s后的表面形貌
Figure 14. Surface morphology of hydrogen-charged and uncharged samples after 1.7 V potentiostatic polarization for 1 200 s in 0.03 mol/L NaHCO3+0.000 1 mol/L NaCl solution under 0 T (a, b) and 0.4 T (c, d) magnetic field
表 1 X70管线钢化学成分
Table 1 Chemical composition of X70 pipeline steel
元素 C Si Mn P S Cr Ti Nb V Ni Cu Mo Fe 质量分数/% 0.05 0.24 1.6 0.01 0.001 0.26 0.015 0.043 0.003 0.01 0.02 0.002 余量 
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[1] ASKARI M, ALIOFKHAZRAEI M, AFROUKHTEH S. A comprehensive review on internal corrosion and cracking of oil and gas pipelines[J]. Journal of Natural Gas Science and Engineering, 2019, 71: 102971. [2] MAO X, LIU X, REVIE R W. Pitting corrosion of pipeline steel in dilute bicarbonate solution with chloride ions[J]. Corrosion, 1994, 50(9): 651-657. [3] XU L Y, CHENG Y F. Corrosion of X100 pipeline steel under plastic strain in a neutral pH bicarbonate solution[J]. Corrosion Science, 2012, 64: 145-152. [4] SIMARD S, MENARD H, BROSSARD L. Localized corrosion of 1 024 mild steel in slightly alkaline bicarbonate solution with Cl- ions[J]. Journal of Applied Electrochemistry, 1998, 28(2): 151-160. [5] EL-NAGGAR M M. Effects of Cl-, NO3- and anions on the anodic behavior of carbon steel in deaerated 0.50 M NaHCO3 solutions[J]. Applied Surface Science, 2006, 252(18): 6179-6194. [6] LU Z P, HUANG D L, YANG W, et al. Effects of an applied magnetic field on the dissolution and passivation of iron in sulphuric acid[J]. Corrosion Science, 2003, 45(10): 2233-2249. [7] LU Z P, CHEN J M. Magnetic field effects on anodic polarisation behaviour of iron in neutral aqueous solutions[J]. British Corrosion Journal, 2000, 35(3): 224-228. [8] LU Z P, HUANG C B, HUANG D L, et al. Effects of a magnetic field on the anodic dissolution, passivation and transpassivation behaviour of iron in weakly alkaline solutions with or without halides[J]. Corrosion Science, 2006, 48(10): 3049-3077. [9] 杨永, 张庆保, 朱万成, 等. 磁场对NaCl溶液中X52管线钢腐蚀行为的影响[J]. 中国腐蚀与防护学报, 2022, 42(3): 501-506. YANG Y, ZHANG Q B, ZHU W C, et al. Effect of magnetic field on corrosion behavior of X52 pipeline steel in NaCl solution[J]. Journal of Chinese Society for Corrosion and Protection, 2022, 42(3): 501-506.
[10] WANG D, LI T J, XIE F, et al. Effect of magnetic field on the electrochemical corrosion behavior of X80 pipeline steel[J]. Construction and Building Materials, 2022, 350: 128897. [11] 惠海军, 戴乾生, 陈凯, 等. 磁场对X60钢材料在长沙地区土壤中腐蚀行为的影响[J]. 腐蚀与防护, 2019, 40(7): 474-478,512. HUI H J, DAI Q S, CHEN K, et al. Effect of magnetic field on corrosion of X60 pipeline steel in soil of Changsha area[J]. Corrosion & Protection, 2019, 40(7): 474-478,512.
[12] QIAO L, MAO X. Thermodynamic analysis on the role of hydrogen in anodic stress corrosion cracking[J]. Acta Metallurgica et Materialia, 1995, 43(11): 4001-4006. [13] YU J G, LUO J L, NORTON P R. Investigation of hydrogen induced pitting active sites[J]. Electrochimica Acta, 2002, 47(25): 4019-4025. [14] CHENG Y F. Analysis of electrochemical hydrogen permeation through X65 pipeline steel and its implications on pipeline stress corrosion cracking[J]. International Journal of Hydrogen Energy, 2007, 32(9): 1269-1276. [15] EJAZ A, LU Z P, CHEN J J, et al. The effects of hydrogen on anodic dissolution and passivation of iron in alkaline solutions[J]. Corrosion Science, 2015, 101: 165-181. [16] EJAZ A, DONG H Y, XU X H, et al. Contribution of diffusing hydrogen to anodic processes and pitting for iron in chloride-bearing bicarbonate solutions[J]. Corrosion, 2022, 78(9): 908-926. [17] MONZON L M A, COEY J M D. Magnetic fields in electrochemistry: the Lorentz force. A mini-review[J]. Electrochemistry Communications, 2014, 42: 38-41. [18] MONZON L M A, COEY J M D. Magnetic fields in electrochemistry: the Kelvin force. A mini-review[J]. Electrochemistry Communications, 2014, 42: 42-45. [19] POURBAIX M. Lectures on electrochemical corrosion[M]. New York: Plenum Press, 1973. [20] DAS N K, SHOJI T. An atomic study of hydrogen effect on the early stage oxidation of transition metal surfaces[J]. International Journal of Hydrogen Energy, 2013, 38(3): 1644-1656. [21] DONG H Y, LI H J, TAO Y Q, et al. Acceleration or retardation by a magnetic field of the anodic processes of iron in molybdate-bearing chloride solutions[J]. RSC Advances, 2024, 14(2): 1258-1266.
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