油气田渗镀涂层防腐蚀技术及展望

介绍了镍磷镀层、渗氮层的性能和在油气田应用的情况,并针对镍磷镀层孔隙率高、镀层厚度不均等缺陷以及渗氮层易于剥落和产生微裂纹等问题提出了建议;对国外涂镀技术和国内石化行业应用渗镀材料的性能及成功应用情况进行了介绍;金属陶瓷涂层具有合理的显微结构、表面硬度较高、抗断裂性强、耐腐蚀和冲蚀性能优异;铝钛共渗钢具有良好的抗湿硫化氢腐蚀、抗氢致开裂(H IC)及硫化物应力腐蚀开裂(SSCC)的能力,其构件在湿硫化氢腐蚀环境的工业应用效果良好,并对渗镀涂层技术作为经济有效的防腐蚀措施将在油气田上得到推广应用进行了展望。

刀具表面沉积的CrMoN渗/镀复合涂层的微观结构和力学性能

采用闭合场非平衡磁控溅射离子镀(CFUMSIP)技术和离子渗氮技术在M2工具钢表面沉积CrMoN渗/镀复合涂层。利用SEM、EDS、XRD、纳米压痕仪、划痕仪和销盘摩擦磨损试验仪研究了该涂层的组织、成分、相结构、硬度、膜/基结合强度和摩擦磨损性能。结果表明,该涂层的表面和截面致密,涂层呈柱状晶生长,为fcc结构,同时图谱中出现了γ-Fe_4N和α-Fe的衍射峰。CrMoN渗/镀复合涂层的膜/基结合强度和摩擦磨损性能明显优于单一制备的CrMoN涂层。

Cyclic oxidation and hot corrosion of Al_2O_3 or Y_2O_3-dispersed low-temperature chromizing coating

Chromium coatings with and without Al_2O_3 or Y_2O_3 particles were prepared by chromizing the as-deposited Ni-film with and without Al_2O_3 or Y_2O_3 particles using a conventional pack-cementation method at 800 ℃. The cyclic oxidation at 800 ℃ and hot corrosion in molten 75% Na2SO4＋25% NaC1 at 800 ℃ of the three different chromizing coatings were investigated. The effects of Al_2O_3 or Y_2O_3 on the cyclic oxidation and hot corrosion behavior of the chromizing coatings were discussed. Microstructure results show that the codeposited Al_2O_3 or Y_2O_3 particles significantly retard the grain growth of the chromizing coating, which increases the cyclic oxidation and hot corrosion resistance of the chromizing coatings, due to the more rapid formation of purer and denser chromia scnle