火电机组过/再热器锅炉管内壁铝化物涂层研究(Ⅲ):实炉服役行为  

Slurry Aluminide Coatings on Boiler Tubes for Overheater/Reheater Application(Ⅲ):Field Testing

作　　者：黄锦阳[1] 钟强[2] 黄浩刚 雷中辉 王鹏 张醒兴 党莹樱[1] 鲁金涛[1] 谷月峰[1] HUANG Jin-yang;ZHONG Qiang;HUANG Hao-gang;LEI Zhong-hui;WANG Peng;ZHANG Xing-xing;DANG Ying-ying;LU Jin-tao;GU Yue-feng(National Engineering Research Center of Clean Coal Combustion for Utility Boilers,Xi′an Thermal Power Research Institute Co.,Ltd,Xi′an 710032,China;Huaneng Hunan Yueyang Power Generation Co.,Ltd,Yueyang 414002,China;Xi′an Yitong Thermal Technology Service Co.,Ltd,Xi′an 710032,China)

机构地区：[1]西安热工研究院有限公司电站锅炉煤清洁燃烧国家工程中心,西安710032 [2]华能湖南岳阳发电有限责任公司,湖南岳阳414002 [3]西安益通热工技术服务有限责任公司,西安710032

出　　处：《表面技术》2021年第7期328-336,共9页Surface Technology

基　　金：陕西省自然科学基础研究计划资助项目(2020JM-716);中国华能集团有限公司科技项目(HNKJ20-H43)。

摘　　要：目的验证抗蒸汽氧化涂层锅炉管在实机服役环境下的综合性能。方法将涂层验证管与对比管样(喷丸管、Super304H母材管)焊接在在役超临界锅炉高温段末级过热器同温区管屏,通过实炉运行,研究真实服役环境下各试验管的综合使役性能。结果实炉服役8600 h后,涂层管表现出了极为优异的抗高温蒸汽氧化性能,管内壁生长约0.3μm厚的保护性Al_(2)O_(3)膜,参比的喷丸管和母材表面氧化膜厚度分别为0.55μm和64.31μm。服役后涂层仍保持双层结构,厚度增加4.5%,平均硬度升高约8.1%,参比的喷丸管样喷丸层部分孪晶消失,细化晶粒合并长大,喷丸层的平均硬度下降21.3%,厚度退化约32%。实炉服役样品650℃拉伸试验表明,涂层验证管的强度与母材持平,涂层管与机组过热器管屏焊缝组织稳定,焊缝各区域内未见铝元素扩散污染,焊接头拉伸样品断裂在无涂层一侧。结论与Super304H母材管和喷丸管相比,涂层管有效提高了管材抗蒸汽氧化能力,内壁氧化膜更薄,生长速率更慢。施加涂层显著提高了管道内表面硬度,对管道服役后的高温力学性能及母材组织无显著影响。施加涂层不影响焊缝组织的稳定性。In order to verify the combination property of the steam oxidation resistance coating boiler tube under field testing conditions,the coated tube and reference tubes(Super304H and Super304H-peening)were welded on the same temperature tube screen section of the high temperature end superheater in boiler.The integrated performance of the tested tubes were evaluated after serving for 8600 h,respectively.The results indicated that the coated tube showed an extremely excellent oxidation resistance performance.The protective Al_(2)O_(3) film with a thickness of only about 0.3μm grew on the inner surface of the coated tube,while the oxidation film thickness of the reference tubes,the Super304H-peening and Super304H,were respectively 0.55μm and 64.31μm.After field testing,the double layer coating microstructure was still retained on the surface of the coated tube,also the thickness and average hardness of the coating all increased by 4.5%and 8.1%.In contrast,the thickness and average hardness of the shot-peened layer all decreased by 21.3%and 32%because of the disappearance of a part of twin boundaries and the growth of the broken grain on Super304H-peening tube.At 650℃,the tensile test results showed that the high temperature strength of the coated tube were equal to the base material super304H after field testing.The weld microstructure of the coated tube with superheater tubes had a good stability during field testing,and the Al pollution caused by diffusion was not found in the weld zone by line scanning of EDS after welding and serving.The tensile fracture of the weld joints occurred on the coating side.The oxidation resistance performance of the coated tube was improved effectively compared with the Super304H-peening and Super304H tubes,also the film was thinner and the growth rate was slower.The hardness of the coated tube inner surface was increased significantly by preparing coating on the surface of Super304H tube.The coating did not have a significant effect on the high temperature strength,the microstruct

关 键 词：实炉服役 涂层锅炉管 SUPER304H 蒸汽氧化 组织 强度 

分 类 号：TG174[金属学及工艺—金属表面处理]