采用现场挂片腐蚀试验研究了5种材料在合成气制乙二醇装置脱重组分塔环境（硝酸质量分数2%~8%、温度116℃）中的腐蚀行为，结合扫描电镜和光学显微镜分别对挂片微观腐蚀形貌和晶间腐蚀深度进行分析。结果表明：904L不锈钢和KY702硝酸级不锈钢具有较好耐全面腐蚀性能，其全面腐蚀速率不超过0.006 mm/a，但具有极轻微的晶间腐蚀敏感性，304L不锈钢、825镍基合金和254SMO不锈钢具有明显的晶间腐蚀敏感性，敏化对825镍基合金和254SMO不锈钢的晶间腐蚀影响较为严重，敏化态254SMO不锈钢和敏化态825镍基合金的晶间腐蚀速率分别是其固溶态晶间腐蚀速率的15倍和16倍。

Corrosion behavior of five materials in the environment of de-heavy oil column for ethylene glycol production plant from syngas (nitric acid mass fraction of 2%-8%, temperature of 116℃) was investigated by coupon corrosion testing on-site. The surface morphology and the depth of intergranular corrosion of the coupons after corrosion test were examined by scanning electron microscope (SEM) and optical microscope (OM). The results indicate that the stainless steel 904L and nitric acid grade stainless steel KY702, whose general corrosion rates were no more than 0.006 mm/a, had good general corrosion resistance, but they had very slight intergranular corrosion sensitivity, while the stainless steels 304L, 254SMO and nickel based alloy 825 had obvious intergranular corrosion sensitivity. Sensitization could affect seriously the intergranular corrosion of nickel based alloy 825 and stainless steel 254SMO. The intergranular corrosion rates of the sensitized stainless steel 254SMO and nickel based alloy 825 increased to 15 times and 16 times, respectively, as compared with their solid solution states.