为明确316L不锈钢CO₂输送管线的垢下腐蚀行为,在模拟垢下腐蚀环境中对316L不锈钢进行了电化学测试及高温高压浸泡试验。结果表明:砂垢和碳酸钙垢均会增加316L不锈钢的垢下腐蚀敏感性,削弱其再钝化能力,砂垢会导致亚稳态点蚀发生,较厚的碳酸钙垢会降低该不锈钢的自腐蚀电位;在100 ℃、5 MPa CO₂环境中,316L不锈钢对垢下腐蚀具有较好的耐受度,但是,当沉积垢与材料形成合适的狭缝时,其具有一定的垢下腐蚀风险。对于高温高含CO₂的316L不锈钢管线需注意防垢、除垢问题。

To clarify the under-deposit corrosion behavior of 316L stainless steel pipelines for CO₂ transport, electrochemical tests and high-temperature and high-pressure immersion tests for 316L stainless steel were carried out in a simulated under-deposit corrosion environment. The results showed that sand and CaCO₃ deposits increased the under-deposit corrosion sensitivity and reduced the re-passivation performance of 316L stainless steel. Sand deposits caused sub-stable pitting corrosion, and thick CaCO₃ deposits reduced the free corrosion potential of the steel. 316L stainless steel had a good under-deposit corrosion resistance at 100 ℃ and 5 MPa CO₂. But the steel was at a risk of under-deposit corrosion when the deposits formed a suitable crevice with the material. It is necessary to pay attention to prevent and remove deposits on 316L stainless steel pipeline in the corrosion environment of high-temperature and high CO₂ partial pressure.