环境因素对不锈钢点蚀电位的影响

用动电位扫描法研究了环境因素对NHB1、NHB3,316L和304四种不锈钢点蚀电位的影响。环境因素的变化范围为温度0°—90℃,PH2—12,NaCl1—5%。实验结果指出,在所研究的条件范围内,E_b随温度的变化规律是,低于某一温度（可称之为E_b转折温度）时,随着温度上升,E_b迅速降低,而高于该温度时,随着温度上升,E_b缓慢降低。这一现象可用Cl^-、O₂和H₂O,在纯化膜表面上的竞争吸附来解释。随着溶液中NaCl浓度加大,E_b总的规律是下降的。在中性和酸性范围内,随PH值加大,E_b是上升的。NHB1和NHB3在低温下不出现点蚀;NHB1和316L在PH12时也不出现点蚀。

The Influence of environmental factors on the pitting potential of stainless steel

Potentiodynamic scanning method was used to study influence of environmental factors on the pitting potentials of types NHB-1、NHB-3、316L and 304 stainless steel. The changing ranges of temperature、PH and Nacl concentration were 0°-90℃、2-2 and 1%-5%,respectively. The experimenta 1 results showed that below certain temperature(It can be called Eb's as tran-siton temperature) the Eb rapidly decrease with the temperature increase while over this temperature,the Eb slowly decrease with the temperature increase in studied conditional ranges, preferential adsorption of Cl^-、O₂ and H₂O on passivating films can be used to explain this pheiomenon. Increasing NaCl concentration,the Eb tend to decrease. The Eb increase with PH increase in neutral and acid solution.pitting corrosion was not found for the types of NHB-1 and NHB-3 stainless steel at Low temperature and for the types of NHB-1 and 316L stanless steel at PH12.