基于COMSOL的石油管线钢应力腐蚀开裂影响因素的研究

基于COMSOL的石油管线钢应力腐蚀开裂影响因素的研究摘要近些年来，伴随着我国石油行业的不断发展，石油管道输送技术也得到了飞快的发展，其安全运行对于能源供应的稳定性和可靠性至关重要。然而国内大部分油田均处于高含水、高碳、腐蚀性介质复杂的环境中，其腐蚀状况日趋严重。另外，原油中往往还存在多介质共存的情况，这就使得管道钢的腐蚀因素更为复杂。因此石油管线易受到各种形式的腐蚀损伤其中应力腐蚀(SCC)是一种极其危险的破坏形式。所以，对SCC的影响因素进行深入研究，并探索有效的防护措施，对于保障石油管线的安全运行具有极其重要的意义。本文基于COMSOL Multiphysics软件，对两种情况下的腐蚀进行了模拟。第一次模拟演示了弹性和塑性变形对管道腐蚀的相互耦合影响，得到了在不同的拉伸应变下，沿腐蚀缺陷长度的应力分布情况。第二次模拟演示了由于二氧化碳和水的湍流而在钢管表面发生的腐蚀，得到了在不同二氧化碳分压下的钢的腐蚀速率。通过建立精确的几何模型和物理场模型，深入探讨了应力水平、腐蚀介质特征以及环境条件等多种因素对应力腐蚀行为的影响。最后通过对模拟结果的分析，得出了在相应条件变化时对腐蚀速率的影响，并根据分析出来的结果，提出了防止石油管线钢应力腐蚀的措施。关键词石油管线：应力腐蚀：弹塑性应力：电化学反应COMSOL-based study on the influencing factorsof stress corrosion cracking of oil pipeline steelAbstractIn recent years,with the continuous development of China's petroleumindustry,oil pipeline transportation technology has also developed rapidly,andits safe operation is very important for the stability and reliability of energysupply.However,most of the domestic oilfields are in a complex environmentof high water cut,high carbon and corrosive media,and their corrosionconditions are becoming more and more serious.In addition,there is often thecoexistence of multiple media in crude oil,which makes the corrosion factors ofpipeline steel more complex.As a result,oil pipelines are susceptible to variousforms of corrosion damage,among which stress corrosion (SCC)is anextremely dangerous form of failure.Therefore,it is of great significance toconduct in-depth research on the influencing factors of SCC and exploreeffective protective measures to ensure the safe operation of oil pipelines.Basedon the COMSOL Multiphysics software.The first simulation demonstrates thecoupling effects of elastic and plastic deformation on pipe corrosion,and thestress distribution along the length of the corrosion defect under different tensilestrains is obtained.The second simulation demonstrates the corrosion thatoccurs on the surface of a steel pipe due to the turbulence of carbon dioxide andwater,and the corrosion rate of the steel at different partial pressures of carbondioxide is obtained.By establishing accurate geometric and physical models,theinfluence of various factors such as stress levels,corrosive media characteristics,and environmental conditions on the stress corrosion behavior is deeplydiscussed.Finally,through the analysis of the simulation results,the influence-Ⅱ-on the corrosion rate under the corresponding conditions is obtained,andaccording to the analysis results,measures to prevent stress corrosion of oilpipeline steel are proposed.Keywords Oil pipeline,Stress corrosion,Elastoplastic stress Electrochemicalreaction-川-目录摘要Abstract....Π第1章绪论111.1课题背景及研究意义1.1.1课题背景11.1.2研究意义21.2国内外研究现状分析…31.3研究的主要内容及方法........1.3.1研究的主要内容....61.3.2研究方案及采用的技术方法1第2章石油管线钢应力腐蚀的机理及COMSOL的介绍.92.1应力腐蚀开裂的概述92.1.1应力腐蚀开裂的定义及特点.44444444444444444444444484:92.1.2应力腐蚀开裂的分类102.2影响石油管线应力腐蚀开裂的物理因素112.2.1环境因素的影响.…112.2.2材料因素的影响.…。122.2.3弹塑性变形对石油管线的相互耦合影响132.3影响石油管线应力腐蚀开裂的化学因素132.3.1腐蚀介质化学成分的影响132.3.2腐蚀介质的PH值的影响…152.3.3石油管线中的C02对应力腐蚀的影响162.4关于C0MS