CAJ | 학술논문

模拟某气田CO2腐蚀环境，利用SEM，EDAX和XRD分析方法，对20号钢管状电感探针的腐蚀机理和失效过程进行了分析研究。结果表明：腐蚀产物分为两层，外层主要由FeCO3晶体和FeS组成，膜层较厚，强度较低且质地疏松多孔；内层主要为FeO和少量FeCl，组成，较外层稍致密，与金属基体间的附着力较差，产物膜易脱落。腐蚀产物膜的多孔特性诱发了局部腐蚀，溶液中Ca^2＋和Cl^-的存在对样品的局部腐蚀起到了促进作用。探针的失效最先从测量试片封堵端开始，焊接工艺遗留残余应力使得此处腐蚀较快，容易发生腐蚀开裂，腐蚀介质从开裂处渗入试片空腔内，加速了探针的失效。
모의모기전CO2부식배경，이용SEM，EDAX화XRD분석방법，대20호강관상전감탐침적부식궤리화실효과정진행료분석연구。결과표명：부식산물분위량층，외층주요유FeCO3정체화FeS조성，막층교후，강도교저차질지소송다공；내층주요위FeO화소량FeCl，조성，교외층초치밀，여금속기체간적부착력교차，산물막역탈락。부식산물막적다공특성유발료국부부식，용액중Ca^2＋화Cl^-적존재대양품적국부부식기도료촉진작용。탐침적실효최선종측량시편봉도단개시，한접공예유류잔여응력사득차처부식교쾌，용역발생부식개렬，부식개질종개렬처삼입시편공강내，가속료탐침적실효。
The corrosion mechanisms and failure process of 20 # steel tubular induction probe in a simulated CO2 corrosion environment of a gas field are investigated by SEM, EDAX and XRD. The results show that the corrosion products are divided into two layers. The outer layer is mainly composed of FeCO3 crystal and FeS, and the film is larger in thickness, low in density and porous in texture. The inner one mainly consists of FeO and a small amount of FeCI=, and the film is slightly denser than the outer layer. The products film is easy to spall off from this layer because of the poor adhesion to metal matrix. Localized corrosion is induced by porous characteristics of products film, and the corrosion process is promoted because of the Ca2+ and C1 in the solution. The corrosion failure starts at the top of 20# steel tubular induction probe. The residual stress by welding accelerated the corrosion, which develops into corrosion cracking. The failure process of probe is accelerated with the corrosive media permeating into the cavity of measurement piece through the corrosion cracks.