在高温高压反应釜中进行了含O₂、CO₂的多元热流体腐蚀试验，结合SEM、EDS和XRD测试，对腐蚀试样的微观形貌和反应机理进行了分析，研究了Cl^-浓度变化对J55（管材）的腐蚀影响。结果表明：在含氧多元热流体中，随着Cl^-含量的升高，J55的腐蚀速率先增后减。当NaCl质量分数为1%时，J55的腐蚀速率最大。多元热流体含CO₂条件下，当Cl^-含量较低时，J55的腐蚀速率随着温度升高而减小；而当Cl^-含量较高时，J55的腐蚀速率随温度升高而增大，故存在临界Cl^-浓度。在含氧的氯离子腐蚀体系中，J55表现出O₂与Cl^-相互竞争的腐蚀特性，当Cl^-含量较低时，O₂在腐蚀反应的初始阶段起主要促进作用；当Cl^-含量较高时，Cl^-成为影响腐蚀速率的主要因素。

The corrosion test of multi-element hot fluid containing O₂ and CO₂ was carried out in a high temperature and high pressure reactor, combined with SEM, EDS and XRD tests, the micro morphology and reaction mechanism of the corrosion samples were also analyzed, and the effect of the change of Cl^- concentration on the corrosion of J55 pipe was studied. The results showed that:in an oxygen-containing multi-element thermal fluid environment, with the increase of Cl^- content, the corrosion rate of J55 first increased and then decreased. When the NaCl mass fraction was 1%, the corrosion rate of J55 was the largest. Under the condition of CO₂ in the multi-element thermal fluid, when the Cl^- content was low, the corrosion rate of J55 decreased with increasing temperature; when the Cl^- content was high, the corrosion rate of J55 increased with increasing temperature. Therefore, there was a critical Cl^- concentration. In the oxygen-containing chloride ion corrosion system, J55 exhibited the corrosion characteristics of O₂ and Cl^- competing with each other. When the Cl^- content was low, O₂ played a major role in promoting the initial stage of corrosion reaction; when the Cl^- content was high, Cl^- became the main factor affecting the corrosion rate.