采用DL-HL-T型 5 kW CO2快速横流激光器对 TA2进行了激光气体氮化处理。采用光学显微镜、扫描电子显微镜、X射线衍射、能谱分析对激光氮化试样进行了微观组织、相组成分析; 采用 MH-3型显微硬度计和 M283恒电位仪与 M352测试分析软件对激光氮化试样进行了显微硬度、自腐蚀电位 Ecorr和自腐蚀电流密度 Icorr的测试与分析。研究结果表明：经过激光表面氮化处理, 在 TA2表面生成了以 TiN为增强相的氮化区域。该区域由氮化层、热影响区和基体三部分构成, 氮化层组织主要由 TiN和琢忆-Ti组成, 厚大约 50滋m, 硬度比较均匀; 热影响区分为两部分：靠近氮化层处为 N在基体中的固溶体琢忆-Ti, 靠近基体处为相变产生的细小针状马氏体。氮化层显微硬度高达 HV0.011 652.1, 而基体仅为 HV0.01 230。TA2激光气体氮化层的自腐蚀电位由基体的-210 mV提高到-144 mV, 自腐蚀电流密度降低为 TA2的 1/10, 提高了 TA2的耐均匀腐蚀和局部腐蚀的性能。

In this paper, the nitrided layers were fabricated by a DL -HL -T -type 5 kW continuous wave CO2 laser on the TA2 surface . This Thesis uses optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy spectrum analysis to analyze the microstructure and phase composition. The microhardness, free corrosion potential, free corrosion current density Icorr are measured and analyzed by the use of MH -3 microhardness tester, M283 potentiostat and M352 test and analysesoftware. The results show that: after laser surface nitriding, the nitride area, reinforced by TiN, generated on the surface of TA2,which consists of the nitride layer, heat affected zone is divided into two parts: one of it is琢'-Ti in which the N diffuse near the nitride layer, the other is the small needle-like martensite near the matrix. TiN nitride layer mainly composed of TiN and琢'-Ti, with about 50滋m thickness and uniform hardness, heat affected zone mainly is small needle琢'-Ti. Nitrided layer hardness is up toHV0.011 652.1, while the matrix is only HV0.01 230. The corrosion potential of the nitrided layer from -210 mV of the base metalincreased to-144 mV, the corrosion current density decreased to 1/10 of the base metal, which improved the uniform corrosion andlocalized corrosion resistance of the TA2.