氮含量对无镍奥氏体不锈钢理化性能的影响

高氮无镍奥氏体不锈钢在多个领域有着广泛的应用前景，然而氮质量分数对其物理性能和化学性能的影响规律尚不十分清晰。设计并冶炼了氮质量分数为0.02%~1.20%的无镍奥氏体不锈钢，对不同氮质量分数钢的晶格常数、线膨胀系数、电阻率、耐汗液腐蚀性能、自腐蚀电位进行了检测和分析。结果表明，氮质量分数的增加使材料的晶格常数随着线性增大，获得了氮质量分数与晶格常数的定量关系。氮质量分数越高，材料的膨胀系数和电阻率越大。不同氮质量分数试验钢经720 h人工汗液腐蚀后，氮质量分数最低(0.02%)和最高(1.20%)时，试验钢严重腐蚀，而其他钢未被腐蚀。试验钢的自腐蚀电位首先随着氮质量分数的增加而升高，峰值出现在氮质量分数为1.05%时，氮质量分数为1.20%的钢其自腐蚀电位下降至低于氮质量分数为0.60%钢的水平。

Effects of nitrogen content on physical and chemical properties of nickel free austenitic stainless steels

High nitrogen nickel free austenitic stainless steels have wide application prospect in many fields. However, the effects of the nitrogen mass fraction on physical and chemical properties are still unclear yet. High nitrogen nickel free austenitic stainless steels with nitrogen mass fraction ranging from 0.02% to 1.20% were designed and melted. The lattice constant, thermal expansion coefficient, resistivity, sweat corrosion resistance, and self corrosion potential were examined and analyzed. The results showed that the lattice constant increased with the nitrogen mass fraction linearly and the quantitative relationship between them was obtained. The higher the nitrogen mass fraction, the larger were both the thermal expansion coefficient and resistivity. After the corrosion by artificial sweat for 720 h, the steels with 0.02% and 1.20% nitrogen were corroded seriously. However, other steels were non corroded. The self corrosion potential increased with the nitrogen mass fraction and the maximum appeared when the nitrogen mass fraction was 1.05% in steel. The self corrosion potential of the steel with the nitrogen mass fraction of 1.20% decreased to a lower level as that of the steel with the nitrogen mass fraction of 0.60%.