粉末冶金技术2025，Vol.43Issue(4)：453-464,12.DOI:10.19591/j.cnki.cn11-1974/tf.2024100012
激光定向能量沉积高Cr低熔点镍基合金显微组织及抗高温熔盐腐蚀性能
Microstructure and corrosion resistance to high-temperature molten salt of high Cr low-melting-point nickel-based alloys by laser directed energy deposition
摘要
Abstract
In view of the serious corrosion and wear failure for the parts under harsh and high-temperature service conditions,the low-melting-point nickel-based alloys with different Cr content(mass fraction)were prepared by laser directed energy deposition(LDED).The effects of Cr content on the microstructure and high-temperature corrosion resistance of the alloys were investigated.The microstructure of the alloys was analyzed by scanning electron microscope(SEM),X-ray diffractometer(XRD),and electron probe microanalyser(EPMA),and the relationship between the microstructure,hardness,and corrosion resistance to high temperature molten salt was discussed.The results show that the microstructure of high Cr low-melting-point nickel-based alloys prepared by LDED is mainly composed of γ-Ni,CrB,and Cr5B3.With the increase of Cr content,the boride content in the alloys increases correspondingly,and the coarse Cr5B3 phases change from block to coarse strip gradually;the daisy(γ-Ni+CrB)eutectic phases disappear,and the lamellar(γ-Ni+Cr5B3)eutectic phases appear.The hardness of the alloys increases with the Cr content,reaching up to HV 360.8,mainly due to the increase of the matrix phase hardness and the boride hard phase content.Compared with TP347H stainless steels,the high Cr low-melting-point nickel-based alloys have the better resistance to high temperature molten salt corrosion,with the increase of Cr content.The alloy samples with 40%Cr show the best corrosion resistance,which is about 15 times higher than that of TP347H.During the high temperature corrosion process,the dense Cr-rich oxide films are formed on the alloy surface,which can effectively prevent the corrosion reaction from invading.On the other hand,Cr element can play the role of sulfur fixation,resulting in the excellent resistance to high temperature molten salt corrosion of the high Cr low-melting-point nickel-based alloys.关键词
激光定向能量沉积/高Cr低熔点镍基合金/显微组织/硬度/高温熔盐腐蚀性能Key words
laser directed energy deposition/high Cr low-melting-point nickel-based alloys/microstructure/hardness/corrosion resistance to high-temperature molten salt分类
矿业与冶金引用本文复制引用
李思勇,刘毅,何佳颖,皇志富,成应晋,坚永鑫..激光定向能量沉积高Cr低熔点镍基合金显微组织及抗高温熔盐腐蚀性能[J].粉末冶金技术,2025,43(4):453-464,12.基金项目
陕西省自然科学基础研究计划-重点项目(2025JC-QYXQ-020) （2025JC-QYXQ-020）
中国博士后基金(2023M732752) （2023M732752）
