目的 研究TA2钛合金在CH4介质中感应渗碳层的组织结构，并评价具有高硬度及高耐磨性的渗碳层在含氟混合酸中的腐蚀行为。方法 在850、880、910 ℃温度下对TA2钛合金进行真空脉冲“强渗-扩散”，通过电化学工作站及浸泡腐蚀评价渗碳层的耐蚀性能。采用XRD、SEM和XPS等方法，对渗碳层的相结构、组织、腐蚀产物及其化学态进行观察和分析。结果 经910 ℃渗碳的TA2钛合金可形成较厚的TiC层，并表现出较好的耐蚀性能。在0.2%HF+0.2%HNO3酸溶液中，120 min前未发生明显腐蚀行为，120 min后腐蚀速率为4.01×10-3 A/cm2。在电化学测试下，腐蚀速率从未渗碳的3.32×10-1 A/cm2降低至1.67×10-2 A/cm2。渗碳试样表面呈全面腐蚀状态，而未渗碳样有点蚀行为。表面腐蚀后的XPS数据拟合显示，Ti元素呈三个能级峰，主要以+4价存在，氟离子的存在是由于取代了Ti—OH中的键形成Ti—F。结论 真空感应渗碳在TA2钛合金表面生成的强化层，对钛合金在低浓度含F-酸中的腐蚀具有一定的防护作用，随渗碳温度的升高，表面渗碳层增厚且具有更高的阻抗膜值和较小的腐蚀电流。此外，表面渗碳层的存在，使钛合金的腐蚀行为从点蚀变为全面腐蚀。

The work aims to study the microstructure of the inductive carburized layer of TA2 titanium alloy in CH4 medium, and evaluate the corrosion behavior of carburized layer with high hardness and high wear resistance in the fluorine-containing mixed acid. "Strong seepage-diffusion" was conducted to TA2 titanium alloy by vacuum pulse at 850 ℃, 880 ℃ and 910 ℃. The corrosion resistance of the carburized layer was evaluated by electrochemical workstation and immersion corrosion. In addition, the phase structure, microstructure, corrosion products and chemical states of the carburized layer were analyzed by XRD, SEM and XPS. The TA2 titanium alloy carburized at 910 ℃ could form a thick layer of TiC, and showed good corrosion resistance. Corrosion behavior of TC6 titanium alloy did not occur within the first 120 min in acid solution (0.2%HF+0.2%HNO3), and the corrosion rate was 4.01×10-3 A/cm2 after 120 min. The corrosion rate decreased from 3.32×10-1 A/cm2 to 1.67×10-2 A/cm2 in electrochemical test. The surface of the carburized sample was in a state of overall corrosion, while the non-carburized sample had a pitting corrosion behavior. Fitting results of XPS data after surface corrosion showed that Ti element presented three energy level peaks, mainly in the form of +4 valence, and the fluoride ion was formed by replacing the bond in Ti—OH to form Ti—F. From the results, the strengthened layer formed by vacuum induction carburizing on the surface of TA2 titanium alloy, has an excellent protective function in low concentration of fluorine-containing mixed acid. With the increase of carburizing temperature, the surface carburized layer becomes thicker and has higher impedance film value and smaller corrosion current. Moreover, the presence of a surface carburized layer changes the corrosion behavior of titanium alloy from pitting corrosion to overall corrosion.