通过金相显微镜、扫描电镜和电化学工作站等设备，研究了固溶态和时效态无硼和含硼（质量分数0.004%）不锈钢的显微组织和耐蚀性。结果表明：固溶态无硼不锈钢和含硼不锈钢的组织都为单一奥氏体，时效态不锈钢中会析出σ相，硼的添加有助于改善不锈钢中富钼σ相的存在形式；相较于无硼不锈钢，含硼不锈钢的自腐蚀电位更正，腐蚀电流密度、点蚀电位和腐蚀速率更小，表明其具有更好的耐蚀性；与无硼不锈钢比，相同热处理条件下含硼不锈钢的容抗弧半径和相位角更大、钝化膜电阻更小；随着时效时间延长，无硼不锈钢与含硼不锈钢的电荷转移电阻和钝化膜电阻都逐渐减小，双电层电容和钝化膜电容都逐渐增大；含硼不锈钢的耐点蚀性能优于无硼不锈钢，这主要与硼加入后改善了不锈钢中σ相的存在形式，提高了钝化膜的致密度和稳定性有关。

The microstructure and corrosion resistance of B-free and B-containing (mass fraction of 0.004%) stainless steels in solid solution state and aging state were studied by means of metallographic microscopy, scanning electron microscopy (SEM) and electrochemical workstation. The results showed that the microstructure of B-free and B-containing stainless steels in solid solution state was single austenite, and σ phase precipitated in stainless steel in aging state. The addition of B was helpful to improve the existence form of Mo-riched σ phase in the stainless steel. Compared with the B-free stainless steel, the B-containing stainless steel had a more positive corrosion potential, and the corrosion current density, pitting potential and corrosion rate of B-containing stainless steel were lower, which indicated that the B-containing stainless steel had better corrosion resistance. Compared with the B-free stainless steel under the same heat treatment conditions, the capacitive arc radius and phase angle of the B-containing stainless steel were larger, and the resistance of passivation film was smaller. As the aging time increased, the charge transfer resistance and passivation film resistance of the B-free stainless steel and the B-containing stainless steel gradually decreased, while the double layer capacitance and passivation film capacitance increased gradually. The pitting resistance of the B-containing stainless steel was better than that of the B-free stainless steel, which was mainly related to the improvement of the existence form of σ phase in stainless steel and the enhancement of density and stability of passivation film due to addition of B element.