目的 通过研究高温氧化特征，定量分析抗氧化涂层对S31254超级奥氏体不锈钢在热处理过程中氧化速率的影响。方法 通过热重分析实验测定S31254超级奥氏体不锈钢恒温氧化增量曲线，调查试样在不同温度下退火过程中的氧化烧损现象，并分析退火试样的纵截面氧化层微观形貌。结果 实验结果显示，当加热温度达到1 300 ℃后，试样的氧化增量曲线由原先的抛物线规律逐渐向线性规律转变。由于MoO3易于挥发，造成了试样高温氧化烧损严重。当退火温度为1 220 ℃时，试样在空气中的平均单面烧损速率约为4.0 μm/h;而当使用抗氧化涂层后，平均单面烧损速率降至3.2 μm/h，涂层防护效果显著。试样在1 220 ℃下退火时生成的氧化层可分为2层，分别是Cr、Fe氧化物组成的内氧化层和Fe氧化物组成的外氧化层。结论 研究结果证明，抗氧化涂层能够显著降低S31254超级奥氏体不锈钢在1 220～1 280 ℃下的氧化速率。

The work aims to quantitatively analyze the effect of anti-oxidation coating on the oxidation rate of S31254 super austenitic stainless steel during heat treatment by studying the characteristics of high-temperature oxidation. The oxidation weight-gained curve of S31254 super austenitic stainless steel at constant temperature was measured by thermogravimetric analysis experiment. The oxidation loss of specimen was investigated during annealing at different temperature, and the microstructure of the oxide layer in the longitudinal section of the annealed specimen was analyzed. The results showed that when the annealing temperature reached 1 300 ℃, the oxidation weight-gained curve of the specimen gradually changed from the original parabolic law to the linear law. The high-temperature oxidation loss of the specimen was serious because MoO3 was easy to gasify. When the annealing temperature was 1 220 ℃, the average single-sided oxidation loss rate of the specimen in air was about 4.0 μm/h. When the anti-oxidation coating was used, the average single-sided oxidation loss rate decreased to 3.2 μm/h. The protective effect of the coating was remarkable. The oxide layer formed in the process of annealing at 1 220 ℃ could be divided into two parts, which were the inner oxide layer composed of oxides of Cr and Fe and the outer oxide layer composed of oxides of Fe. The results illustrate that the anti-oxidation coating can significantly reduce the oxidation rate of S31254 super austenitic stainless steel at 1 220~1 280 ℃.