稀土元素对油管激光合金化层组织及性能影响

在N80油管表面预置Ni-Cr-Ti-B4C-La_2O_3合金粉末,通过激光处理获得与基体冶金结合良好的合金化层,研究La_2O_3添加量对激光合金化层组织和性能的影响。利用光学显微镜(OM)、扫描电子显微镜(SEM)和显微硬度计对合金化层的组织及显微硬度进行测试分析,利用电化学测试系统测试合金化层的动电位极化曲线。结果表明,La_2O_3添加量影响N80油管表面激光合金化层原位生成TiB_2,TiC相的尺寸及分布、硬度及耐蚀性。当La_2O_3的加入量为0.5%时,激光合金化层中TiB_2,TiC增强相细小且分布均匀,硬度最高,耐蚀性得到改善。

Effect of rare earth elements on microstructure and properties of laser alloying layers on N80 oil tube

The N80 oil tube surface was preset with Ni-Cr-Ti-B4C- La2O3 alloying powders, the alloying layer which was metallurgically bonded with the base metal was obtained through laser treatment. The effect of rare earth elements on microstructure and properties of laser alloying layers on N80 oil tube was studied in this paper. The microstructure and microhardness of laser alloying layer were tested by optical microscopy (OM), scanning electron microscopy (SEM) and microhardness tester. The corrosion resistance was also tested by electrochemical corrosion testing equipment. The results show that the content of La2O3 affects the size and distribution of in-situ synthesis of TiB2 and TiC, hardness and corrosion resistance of laser alloying layers. When the content of La2O3 is 0.5%, the properties of laser alloying layers are improved, such as the reinforcing phase of TiB2 and TiCis tiny and well-distributed, the hardness is highest, and the corrosion resistance is also enhanced.