20号钢无缝钢管腐蚀穿孔失效原因分析  

Failure Analysis of Corrosion and Perforation for 20#Seamless Steel Tube

作　　者：丛深 冯洪 段晓鹏 宋恩鹏 靳权 王康 CONG Shen;FENG Hong;DUAN Xiaopeng;SONG Enpeng;JIN Quan;WANG Kang(CNPC Tubular Goods Research Institute,Xi′an,Shaanxi 710077,China;Qinghai Oilfield Material Equipment Company,Dunhuang,Gansu 736200,China;Changqing Oilfield Branch No.6 Gas Production Plant,Xi′an,Shaanxi 710018,China)

机构地区：[1]中国石油集团工程材料研究院有限公司,陕西西安710077 [2]青海油田物资装备有限公司,甘肃敦煌736200 [3]长庆油田公司第六采气厂,陕西西安710018

出　　处：《石油管材与仪器》2023年第4期84-90,共7页Petroleum Tubular Goods & Instruments

摘　　要：为了确定西部某油田无缝钢管腐蚀穿孔失效的原因,对失效的无缝钢管样品进行了外观、理化性能、金相组织、腐蚀产物元素和成分等的试验分析。试验分析结果表明,失效无缝钢管的化学成分和布氏硬度试验结果均符合GB/T 12459—2017标准的要求,3^(#)无缝钢管样品的伸长率不符合该标准的要求;无缝钢管材料中含有少量的非金属夹杂物,金相组织为P+F;腐蚀坑中的物质主要由O、Fe、S、Cl、Si、Ca和C等元素构成;腐蚀产物主要由Fe_(3)O_(4)、Fe_(2)O_(3)和FeOOH组成。根据腐蚀产物的化学成分,该无缝钢管腐蚀穿孔主要是由土壤中的溶解氧腐蚀所引起,失效形式为无缝钢管外壁局部腐蚀导致的腐蚀穿孔。In order to determine the cause of corrosion and perforation of seamless steel tube in a western oil field,the appearance,physical and chemical properties,metallographic structure,elements and components of corrosion products of the failed seamless steel tube were tested and analyzed.The results show that the chemical composition and Brinell hardness test results of the failed seamless steel tube are in accordance with GB/T 12459-2017 standard.However,the elongation of the sample of 3#seamless steel tube sample is not in accordance with the standard.The seamless steel tube material contains a small amount of non-metallic inclusions,and the metallographic structure is P+F.The material in the corrosion pits is mainly composed of O,Fe,S,Cl,Si,Ca and C.The corrosion products are mainly composed of Fe_(3)O_(4),Fe_(2)O_(3)and FeOOH.According to the chemical composition of corrosion products,the corrosion perforation of the seamless steel tube is mainly caused by the corrosion of dissolved oxygen in the soil,and the failure form is the corrosion perforation caused by the local corrosion of the outer wall of the seamless steel tube.

关 键 词：无缝钢管 腐蚀穿孔 溶解氧腐蚀 电化学腐蚀 

分 类 号：TE973[石油与天然气工程—石油机械设备]