蒸镀法制备船用焊条抗吸潮膜研究

碱性焊条的吸潮问题严重影响焊接质量。采用蒸镀高级脂肪酸(硬脂酸、棕榈酸、肉豆蔻酸、月桂酸)的方法对焊条进行表面处理制备了抗吸潮保护膜,并利用红外光谱和扫描电镜对抗吸潮焊条表面进行测试。结果表明:蒸镀在焊条表面的脂肪酸是物理吸附,薄膜厚度较小、紧密覆盖在焊条表面,在焊接时可快速蒸发;蒸镀制备的焊条工艺性能较好,与原焊条差别不大,其熔敷金属扩散氢含量随蒸镀时间的延长而不断增加;当蒸镀时间为4~12 h,4种脂肪酸的扩散氢的含量很接近,当超过12 h后逐渐增大。蒸镀法制备的抗吸潮保护膜可以减缓吸潮,但不能完全阻止水分进入焊条内部。

Preparation of moisture-resistant coating for marine electrode by evaporating deposition

Absorbing moisture of alkaline electrode may seriously affect the quality of welding. Method of evaporating deposition of higher fatty acids(stearic acid,palmitic acid,myristic acid,lauric acid)was adopted to prepare a protective film for resisting moisture absorption. The results of FT-IR and SEM microscope indicate that the fatty acid is physical adsorption,and can evaporate quickly in welding. The diffusible hydrogen of weld metal of electrode prepared by evaporating deposition steadily increases in pace with the time of evaporating. The content of diffusible hydrogen is substantially the same for the four fatty acids within 4-12 h,and gradually widens after 12 h. The protective film can reduce moisture absorption of electrode,but can't prevent water from entering weld electrode.