本文通过电化学动电位再活化法（EPR）并结合扫描电镜（SEM）和金相显微镜评价了热处理温度对304不锈钢晶间腐蚀的影响。同时研究了不同敏化程度的304不锈钢铬离子析出量情况，以及浸泡时间和浸泡温度对同一敏化程度的不锈钢铬离子析出量的影响。实验结果表明，304不锈钢在低温下进行热处理，可以避免晶间腐蚀的发生。在500 ℃~650 ℃下热处理，随着温度的上升样品的敏化度增加，并在650 ℃左右尤为严重。随着温度的继续上升，样品的贫铬现象弱化，敏化度下降。在酸性溶液中随着敏化度的升高，晶间腐蚀所导致的铬析出量也随着增加。但在中性溶液中，敏化度高低对铬析出量影响甚小。在不同浸泡液中，浸泡时间的延长对试样的自腐蚀电位有着不同程度的影响，从而改变试样的耐腐蚀性能。浸泡液温度的上升，均会加速已发生敏化的试样腐蚀，使得铬离子析出量增大且在含氯酸性溶液中铬离子析出量最为严重。

The intergranular corrosion of 304 stainless steel was evaluated by electrochemical potentiodynamic reactivation (EPR) combined with scanning electron microscopy (SEM) and metallographic microscopy. The release of chromium ions from 304 stainless steel specimens at different degrees of sensitization and the effects of the time and temperature of immersion on chromium ion release from specimens at the same degree of sensitization were studied. The results showed that 304 stainless steel could avoid intergranular corrosion, which annealed at a low temperature. As annealing temperature increased from 500 ℃ to 650 ℃, the corresponding degree of sensitization also increased. The specimens suffered severe intergranular attack after being exposed at 650 ℃. While the annealing temperature continued to increase, chromium depletion weakened, and sensitization decreased. With the increase in the degree of sensitization, chromium ion precipitation increased in acid solutions as well. However, there was no effect of the degree of sensitization on chromium ion release in neutral chlorine solution. In different soaking solutions, the immersion time had different degrees of impact on the self-corrosion potential of the specimens, resulting in changes in resistance of specimens to corrosion. The increase in immersion temperature accelerated the corrosion of sensitized specimens, leading to a sharp increase in chromium ion precipitation.

广东省质监局科技计划项目（2016ZZ06）