纳米晶涂层对DD98M合金热腐蚀行为的影响  

Influences of Nanocrystalline Coating on Hot Corrosion Behavior of DD98M Alloy

作　　者：时龙 辛丽[2] 王福会[2] 陈庆[1] 田爱华[1] 吕雪飞[1] 

机构地区：[1]吉林化工学院机电工程学院 [2]中国科学院金属研究所腐蚀与防护实验室,沈阳110016

出　　处：《中国表面工程》2017年第5期1-9,共9页China Surface Engineering

基　　金：国家重点基础研究发展计划(973计划)(2012CB625100);国家自然科学基金(U1537107);吉林化工学院校级重大科研项目(2016016)~~

摘　　要：为了研究纳米化对DD98M合金热腐蚀行为的影响,采用磁控溅射的方法制备了与其成分相同的纳米晶涂层。运用XRD、SEM/EDS、TEM分别分析了涂层的结构和热腐蚀性能。结果表明:沉积态的纳米晶涂层呈柱状晶结构,有大量沿沉积方向的柱状晶界,晶粒宽度为30~100 nm。涂层为单一的γ相且具有明显的(111)择优取向。在900℃Na_2SO_4+25%K_2SO_4以及Na_2SO_4+25%Na Cl盐中,DD98M合金在5 h内就发生了严重腐蚀。纳米晶涂层在熔融Na_2SO_4+25%K2SO4中表现出了良好的热腐蚀性能,但在Na_2SO_4+25%Na Cl盐中,纳米晶及其预氧化涂层对DD98M合金的抗热腐蚀性能的提高并不明显。纳米晶促进了涂层表面Al_2O_3膜在空气中和熔融Na_2SO_4+25%K2SO4盐中的快速形成,显著提高了DD98M合金在硫酸盐中的抗热腐蚀性能,预氧化处理则使涂层的抗热腐蚀能力进一步提高。In order to investigate the influences of nanocrystallization on the hot corrosion behavior of DD98M alloy, a nanocrystalline coating with the same composition as DD98M alloy was deposited by means of a magnetron sputtering method. The structure and hot corrosion properties of the coatings were analyzed by XRD, SEM/EDS, and TEM, respectively. The results indicate that the DD98M sputtered nanocrystalline coating possesses a typical columnar structure with the width of the columnar grains ranges from 30 to 100 nm. The coating is composed only of γ phase and exhibits an apparent （111） texture. After exposure for 5 h in molten Na2SO4＋25%K2SO4 and Na2SO4＋25%NaCl salts at 900 ℃, DD98M alloy occurs severe corrosion. The nanocrystalline coating exhibits good hot corrosion performance in the molten sulfate; however, in molten Na2SO4＋25% NaCl salt, the corrosion resistance of DD98M alloy is not significantly enhanced by the nanocrystalline coating and the pre-oxidized coating. Nanocrystallization prompts the rapid formation of alumina scale on the coating surface in air and in molten sulfate, significantly improves the corrosion resistance of DD98M alloy in sulfate, and the pre-oxidation treatment of the sputtered coating leads to an even better effect.

关 键 词：DD98M合金 纳米晶涂层 热腐蚀 预氧化 

分 类 号：TG174.444[金属学及工艺—金属表面处理] TG113.23[金属学及工艺—金属学]