Fe-20Mn-7Cr-0.9Mo钢与TWIP钢组织和腐蚀性能的比较研究  

Comparative Study on Microstructure and Corrosion Property of Fe-20Mn-7Cr-0.9Mo Steel and TWIP Steel

作　　者：郭大山 肖春江 王通 莫德敏 GUO Da-shan;XIAO Chun-jiang;WANG Tong;MO De-min(HBIS Group Wusteel Company,Henan Wugang 462500,China)

机构地区：[1]河钢集团舞钢公司,河南舞钢462500

出　　处：《表面技术》2023年第8期301-308,共8页Surface Technology

摘　　要：目的重点探究Fe-20Mn-7Cr-0.9Mo钢在中国3块不同油田采出水模拟液中的腐蚀行为,为其在石油管材上的应用提供理论指导。方法在Fe-25Mn-3Si-3Al TWIP钢中添加Cr和Mo元素,降低Mn元素含量,设计制备Fe-20Mn-7Cr-0.9Mo钢。采用X射线衍射仪(XRD)和透射电子显微镜(TEM)对Fe-20Mn-7Cr-0.9Mo钢的微观组织进行分析。利用电化学工作站测试Fe-20Mn-7Cr-0.9Mo钢在3种油田采出水模拟液中的极化曲线和电化学阻抗谱,并使用扫描电子显微镜(SEM)对腐蚀产物进行微观分析。同时,以相同环境中Fe-25Mn-3Si-3Al TWIP钢的腐蚀行为作为对照。结果Fe-20Mn-7Cr-0.9Mo钢组织以奥氏体为主,其晶粒中含有大量层错、退火孪晶和高密度位错结构的马氏体。通过分析极化曲线可知,与Fe-25Mn-3Si-3Al TWIP钢相比,Fe-20Mn-7Cr-0.9Mo钢在3种油田采出水模拟液中均发生了钝化,腐蚀电位提高,腐蚀电流密度明显降低,分别为1.7、0.08、2.1μA/cm^(2)。通过分析电化学阻抗谱可知,Fe-20Mn-7Cr-0.9Mo钢在3种油田采出水模拟液中均呈现单一的电容回路,极化电阻Rp分别为3111、5322、3582Ω·cm^(2),而Fe-25Mn-3Si-3Al TWIP钢在3种油田采出水模拟液中呈现1个电容回路和1个电感回路,相应的极化电阻Rp仅为530、273、528Ω·cm^(2),远小于Fe-20Mn-7Cr-0.9Mo钢。在3种油田采出水模拟液中,Fe-20Mn-7Cr-0.9Mo钢试样表面仅存在少量腐蚀产物,而Fe-25Mn-3Si-3Al TWIP钢试样表面存在大量的腐蚀产物,并形成了腐蚀产物膜。结论Cr与Mo元素的添加和Mn元素含量的减少,降低了Fe-20Mn-7Cr-0.9Mo钢的堆垛层错能,导致晶粒中形成了大量层错、退火孪晶和少量马氏体。在3种油田采出水模拟液中,Cr与Mo元素的添加、Mn元素含量的减少和晶粒中退火孪晶的形成有效提高了Fe-20Mn-7Cr-0.9Mo钢的耐蚀性。With the gradual increase of oilfield production costs,the corrosion resistance of oil pipelines has received more and more attention.In order to obtain oil pipelines with excellent corrosion resistance,based on the Fe-25Mn-3Si-3Al TWIP steel,Cr and Mo were added,Mn content was reduced to design and produce Fe-20Mn-7Cr-0.9Mo steel.According to the difference of oilfield environment in China,this paper focused on the corrosion behavior of Fe-20Mn-7Cr-0.9Mo steel in three oilfield produced water simulation liquids,and provide theoretical guidance for its application in oil pipelines.Firstly,the microstructure of Fe-20Mn-7Cr-0.9Mo steel was analyzed by XRD and TEM.Then,the polarization curve and EIS of Fe-20Mn-7Cr-0.9Mo steel were investigated in three oilfield produced water simulation liquids by Electrochemical Workstation.The scanning range of the polarization curve was−1.15 V to−0.3 V,and the scanning rate was 0.001 V/s.The EIS measurements were performed at open circuit potential and the spectra were acquired in the frequency range 10−2 Hz to 105 Hz with an amplitude of 10 mV.The corrosion products were analyzed by SEM after the electrochemical test.Meanwhile,the corrosion behavior of Fe-25Mn-3Si-3Al TWIP steel in the same environment was used as a control experiment.The results showed that the microstructure of Fe-20Mn-7Cr-0.9Mo steel was dominated by austenite,and the grains contained a large number of stacking faults,annealing twins and martensite with a high-density dislocation structure.The addition of Cr and Mo,and the reduction of Mn content reduced the stacking fault energy of Fe-20Mn-7Cr-0.9Mo steel,resulting in the formation of a large number of stacking faults,annealing twins and a small amount of martensite in the grains.The polarization curves analysis showed that compared with Fe-25Mn-3Si-3Al TWIP steel,Fe-20Mn-7Cr-0.9Mo steel was passivated in three oilfield produced water simulation liquids,the corrosion potential was increased,and the corrosion current density was significantly reduced,wh

关 键 词：Fe-20Mn-7Cr-0.9Mo钢 SFE值 退火孪晶 耐蚀性 

分 类 号：TG142.3[一般工业技术—材料科学与工程]