Effects of Cold Work, Sensitization Treatment, and the Combination on Corrosion Behavior of Stainless Steels in Nitric Acid
Effects of Cold Work, Sensitization Treatment, and the Combination on Corrosion Behavior of Stainless Steels in Nitric Acid
复制标题
冷加工、敏化处理及其组合对不锈钢在硝酸中腐蚀行为的影响
作者：
M. Mayuzumi;J. Ohta;T. Arai
摘要研究了两种不锈钢（SS）在硝酸（HNO3）中的腐蚀行为，考察了冷加工（CW）、敏化热处理（Sens.）和复合热处理（CW + Sens.）的影响。超低碳（304ELC型SS [UNS S30403]）固溶处理的304型SS （UNS S30400）的腐蚀速率随着时间的推移而增加，在浸泡1000 h后达到恒定值。然而，25% Cr-20% Ni-Nb （310Nb型SS [UNS S31040]）的腐蚀速率从浸泡初期开始就保持不变。连续水可以减轻固溶处理的SS的腐蚀。连续水对两种类型的SS的影响不同，其中敏化热处理的304ELC型SS的腐蚀速率较高，而310Nb型SS的腐蚀速率较低。经各处理后，310Nb型钢的耐蚀性优于304ELC型钢。敏化处理后的304ELC SS晶界区的铬浓度低于固溶处理后的，但在晶界区的铬浓度没有升高。
Abstract Corrosion behavior of two stainless steels (SS) was investigated in nitric acid (HNO3) for the effect of cold work (CW), sensitization heat treatment (Sens.), and a combination (CW + Sens.). The corrosion rate of the solution-treated type 304 SS (UNS S30400) with extra-low carbon (type 304ELC SS [UNS S30403]) increased with time and reached constant values after 1,000 h of immersion. However, constant corrosion rates were obtained for 25% Cr-20% Ni-Nb (type 310Nb SS [UNS S31040]) from the initial stage of immersion. CW mitigated corrosion of the solution-treated SS. The effect of CW was different on the two types of SS, with the sensitization heat-treated type 304ELC SS showing higher corrosion rates and type 310Nb SS lower corrosion rates by CW. Corrosion resistance of type 310Nb SS was superior to type 304ELC SS after all treatments. Chromium concentration of the sensitization-treated type 304ELC SS was lower in the grain-boundary region than of the solution-treated one, although no chromium ca...