正火处理对304和304L不锈钢在硝酸中耐蚀性的影响  

Effects of Normalizing Treatment on Corrosion Resistance of 304 and 304L Stainless Steel in Nitric Acid

作　　者：孔令真[1] 詹宇鹏 张瑜[1] 徐光远 王奎升[1] 

机构地区：[1]北京化工大学机电工程学院,北京100029 [2]吉林石化检测中心,吉林吉林132021

出　　处：《材料保护》2017年第5期100-104,共5页Materials Protection

基　　金：北京市与中央高校共建项目资助

摘　　要：开展热处理对304和304L不锈钢在硝酸中耐蚀性的影响研究,可为不锈钢现场使用过程中的焊接和热处理提供指导。利用正火处理模拟不锈钢在焊接或者热加工过程的受热过程,考察304和304L不锈钢在硝酸中的耐蚀性随受热温度和时间的变化规律。利用电化学动电位再活化法(DL-EPR)与交流阻抗谱法(EIS)研究了不同正火处理条件对304和304L不锈钢在硝酸中耐蚀性的影响。结果表明:2种材料经650℃正火处理后敏化度均为最大值。经900℃正火处理后,304不锈钢的晶粒略有减小,敏化度与未经正火处理的试样相比略有增大,304L不锈钢的晶粒略有增大,敏化度与未经正火处理的试样相比略有减小。304和304L不锈钢经650℃正火处理后,在硝酸介质中其钝化膜的保护能力变差。随保温时间的延长,其在硝酸中的耐蚀性也逐渐降下降。The normalization process was used to simulate the heating process of stainless steel during welding or hot working. The changes of the corrosion resistance for 304 and 304L stainless steel in nitric acid with the heating temperature and time were studied. Effects of different normalizing treatment conditions on corrosion resistance of 304 and 304L stainless steel in nitric acid were investigated by means of double-loop electrochemical potentiokinetic reactivation （DL-EPR） and electrochemical impedance spectroscopy（EIS） methods. Results showed that the sensitization degrees of the specimens reached the maximum after heat-treatment at 650 ℃. After normalizing treatment at 900 ℃, the grain of 304 decreased slightly and the sensitization of the specimen slightly increased, compared with the specimen without normalizing treatment. Whereas the grain of 304L increased slightly and the degree of sensitization slightly decreased, compared to the non- heat treated specimens. After normalizing treatment at 650 ℃, the protect effects of the passivation film of the 304 and 304L specimen got worse in nitric acid medium. With the prolongation of holding time, the corrosion resistance in nitric acid was gradually reduced.

关 键 词：正火处理 不锈钢 晶间腐蚀 再活化法 电化学阻抗谱 耐蚀性 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG161[金属学及工艺—金属材料]