2205双相不锈钢在NH_4Cl垢下腐蚀行为研究  

Study on NH_4Cl Under-deposit Corrosion Behavior of 2205 Duplex Stainless Steel

作　　者：殷雪峰[1] 莫少明[1] 韩磊[1] 兰正贵[1] 

机构地区：[1]中国石化青岛炼油化工有限责任公司,山东青岛266500

出　　处：《石油化工腐蚀与防护》2015年第3期12-16,共5页Corrosion & Protection In Petrochemical Industry

摘　　要：针对NH4Cl的腐蚀环境,选择2205双相不锈钢及碳钢在NH4Cl水溶液及潮湿NH4Cl中的腐蚀进行对比试验,检测分析NH4Cl水溶液和潮湿NH4Cl介质中双相钢、碳钢均匀腐蚀及点蚀的腐蚀速率。结果表明:碳钢、双相钢在NH4Cl水溶液和潮湿盐环境下腐蚀状态均为局部腐蚀,表现为点蚀,随着温度升高腐蚀加剧。无论是碳钢还是双相钢,在潮湿NH4Cl中的腐蚀比在NH4Cl水溶液中腐蚀更严重,碳钢与双相钢在60℃温度下潮湿NH4Cl的腐蚀速率分别为6.270 mm/a和0.039 mm/a,但双相钢点蚀深度大大高于同条件下的碳钢。在实验9 d时间内潮湿NH4Cl盐环境下,碳钢点蚀深度在100μm左右,但双相钢的点蚀深度超过了450μm。因此2205双相钢在潮湿NH4Cl盐环境下可能出现在较短周期内就腐蚀穿孔的情况。2205 duplex stainless steel and carbon steel were selected for comparison corrosion testing in NH4 Cl aqueous solution and clamp NH4Cl salt. The uniform corrosion rate and pit corrosion rate of duplex stainless steel in NH4Cl aqueous solution and damp NH4Cl salt were analyzed. The results show that the carbon steel and duplex stainless steel suffer from local corrosion in the environment of NH4Cl aqueous solution and damp NH4Cl salt, i. e pit corrosion. The corrosion becomes increasingly serious with rising temperature. The corrosion in damp NH4Cl salt is more serious than that in NH4Cl aqueous solution. The corrosion rates of carbon steel and duplex stainless steel under 60℃ damp NH4 Cl salt environment are 6.27 mm/a and 0.039 mm/a respectively. Whereas, the pit of pit corrosion of duplex stainless steel is much deeper than that of carbon steel under the same conditions. In the 9 days, experiment in damp NH4Cl salt environment, the corrosion pit depth of carbon steel is about 100 μm and that of duplex stainless steel is over 450 μm. The localized pitting corrosion might perforate the base material in a very short time in the corrosive media of damp NH4Cl deposit.

关 键 词：双相不锈钢 NH4CL 腐蚀试验 腐蚀分析 

分 类 号：TE986[石油与天然气工程—石油机械设备] TG172.6[金属学及工艺—金属表面处理]