新型HFW焊管的耐腐蚀性能  

Corrosion Resistance Analysis of New HFW Welded Pipe

作　　者：李霄[1] 李磊磊 牛辉[2,3] 黄晓辉 韦奉[2,3] 吕祥鸿 LI Xiao;LI Lei-lei;NIU Hui;HUANG Xiao-hui;WEI Feng;LYU Xiang-hong(Xi’an Key Laboratory of High Performance Oil and Gas Field Materials,School of Material Science and Engineering,Xi’an Shiyou University,Xi’an 710065,China;Welded Pipe Research Institute of Baoji Petroleum Steel Pipe,Shaanxi Baoji 721008,China;National Petroleum and Natural Gas Pipe Engineering Technology Research Center,Shaanxi Baoji 721008,China)

机构地区：[1]西安石油大学材料科学与工程学院西安市高性能油气田材料重点实验室,西安710065 [2]宝鸡石油钢管有限责任公司钢管研究院,陕西宝鸡721008 [3]国家石油天然气管材工程技术研究中心,陕西宝鸡721008

出　　处：《表面技术》2023年第4期251-260,共10页Surface Technology

基　　金：陕西省2021年自然科学基础研究计划项目(2021JQ-594);西安石油大学研究生创新与实践能力培养项目(YCS20212111)。

摘　　要：目的 研究采用高频直缝焊接(HFW)制成新型含Cu焊管母材和焊接接头在硫酸盐还原菌(SRB)环境中的腐蚀行为,为含Cu焊管提供基础数据。方法 通过失重法获得含Cu钢母材、接头及对比材料L360在SRB中的腐蚀速率,采用光学电子显微镜(OM)和透射电子显微镜(TEM)研究了含Cu钢的微观组织结构和析出相成分。通过扫描电子显微镜、激光共聚焦显微镜对腐蚀后的表面腐蚀形貌、细菌形貌和点蚀深度进行分析,利用EDS区域扫描和面扫描对腐蚀产物成分及元素分布状态进行分析。结果 新型含Cu钢金相组织为粒状贝氏体、多边形铁素体和少量的珠光体,透射电镜观察发现表面析出了大量弥散分布的ε-Cu相。在SRB环境中,含Cu钢母材、焊接接头和L360的腐蚀速率分别为0.007 1、0.0239、0.010 0 mm/a。通过腐蚀产物、细菌分布及形态的扫描电镜观察发现,在含Cu钢母材表面未发现结构完整的生物膜,腐蚀介质中的材料表面水解产生的Cu离子有效破坏腐蚀初期快速附着在金属表面的生物膜,从而形成“包状物”残留在金属表面,附近发现萎缩和组织液溢出的细菌,含Cu钢焊接接头焊缝区域生物膜结构完整,有大量细菌吸附且生物活性良好,微生物膜下产生腐蚀坑造成局部膜层破裂,点蚀严重。结论 在SRB环境中新型HFW焊管材料的平均腐蚀速率、点蚀密度和点蚀深度均低于L360,即Cu合金化处理金属表面析出ε-Cu相具有优良杀菌性能,从而减缓含Cu钢的腐蚀,经过HFW焊接后,接头焊缝区域点蚀敏感性增强,耐蚀性能下降。The new Cu-bearing High Frequency Welding(HFW)steel for welded pipes is prepared by Cu alloying,using a 150 kg vacuum induction furnace,forging the ingot into a billet,followed by solution treatment at 1050℃.The treated billet is made into a steel plate using a controlled rolling and cooling process,with a 1 h ageing precipitation at 550℃.The treated steel plates are rolled into round tubes which are welded by high frequency welding technology.The Cu alloying improves the surface properties of the material and gives it good antibacterial properties.This paper investigates the corrosion behaviour of the new Cu-bearing HFW welded pipe base material and welded joint,conventional welded pipe material L360,in the SRB environment for simulated corrosion experiments to explore its corrosion resistance and reveal the bactericidal mechanism of the antibacterial relative microorganisms in the material.The experimental solution is a simulated microbial corrosion environment solution,the microorganism used in this paper is sulfate-reducing bacteria(SRB)for corrosion experiments.The SRB strain was activated by using SPX-250B biochemical incubator at 37℃.The activated SRB solution was injected into a Cl‒solution at a concentration of 34000 mg/L.Corrosion specimens were taken from welded Cu-bearing steel base material,welded joint and L360 pipeline steel and machined using high-precision wire-cutting to produce 50 mm×10 mm×3 mm corrosion hangers.The corrosion weight loss test was selected at a temperature of 37℃and the test period was 30 days.Before the experiments,the specimens were ground with steel sandpaper to eliminate mechanical processing traces,and the de-oiled and dehydrated specimens were placed in a dryer to dry,and the size and mass of the experimental hangings were recorded to 0.001 mm and 0.1 mg respectively.The corrosion products were removed from the specimens for weighing and calculating the corrosion weight loss rate,the uniform corrosion rate was calculated according to NACE SP 0775-2018 standard,

关 键 词：HFW焊管 Ε-CU相 抗菌钢 微生物腐蚀 硫酸盐还原菌(SRB) 

分 类 号：TG172[金属学及工艺—金属表面处理]