Cr元素含量对镍基合金涂层抗热腐蚀行为的影响  

Influence of Cr content on hot corrosion behavior of Nickelbased alloy coatings at high temperature

作　　者：陈丽艳[1] 程杰[1] 吴玉萍[1] 龙伟漾 

机构地区：[1]河海大学力学与材料学院,南京210098

出　　处：《焊接学报》2017年第4期103-106,共4页Transactions of The China Welding Institution

摘　　要：采用高速电弧喷涂技术在20G钢基体表面制备三种铬含量不同的镍基合金涂层.光学显微镜、X射线衍射、扫描电镜和能谱分析等技术对涂层微观组织结构、相组成及成分进行分析.选用摩尔比为7∶3的Na_2SO_4+K_2SO_4水溶液涂敷刷在涂层表面,分析涂层在650℃下的抗热腐蚀性能.结果表明,涂层的腐蚀动力学曲线基本符合抛物线规律;四种涂层表面均形成了致密连续的NiO和Cr_2O_3保护膜.随着铬含量升高,涂层表面氧化膜中Cr_2O_3含量升高,NiO逐渐减少,涂层抗热腐蚀性能明显提高.Ni-30Cr,Ni-45Cr,Ni-50Cr涂层抗热腐蚀性能分别为20G钢基体的10,15和20倍;Ni-50Cr涂层抗腐蚀性能是美国Tafa 45CT材料的1.4倍.Three coatings were deposited on 20G steel by high velocity arc spay technique.Microstructures of these coatings were characterized by optical microscope,scanning electric microscope equipped with EDS.Phases were identified by X-ray diffraction analysis.Hot corrosion trials of these high Cr content coatings were conducted under the mixed sulfates Na_2SO_4+K_2SO_4 layer at650℃.The results showed that hot corrosion kinetic curves fitted well to the parabolic laws,NiO and Cr_2O_3 protective oxide scales have been formed on the surface of four corroded coatings.As the increasing Cr content,the Cr_2O_3 content in the protective oxide scales was gradually increased and the NiO content was reduced,resulted in a significantly enhance in hot corrosion resistance.The corrosion resistance properties of the Ni-30Cr,Ni-45Cr and Ni-50Cr were approximately 10,15 and 20 times higher than that of 20G steel.In addition,the hot corrosion resistance of Ni-50Cr coating was about 1.4 times of that of Ni-Cr-Ti coating(Tafa 45CT).

关 键 词：高速电弧喷涂 镍基合金 涂层 热腐蚀 

分 类 号：TG424[金属学及工艺—焊接]