Effect of surface morphology and microstructure on the hot corrosion behavior of TiC/IN625 coatings prepared by extreme high-speed laser cladding. (June 2022)

• Record Type: Journal Article
• Authors: Chen, Lan; Zhang, Xinzhou; Wu, Yue; Chen, Chen; Li, Yongjian; Zhou, Wangfan; Ren, Xudong
• Is Part Of: Corrosion science. Volume 201(2022)
• Publication Date: 2022-06
• Subjects: Extreme high-speed laser cladding -- TiC/IN625 coating -- Microstructure -- Hot corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110271
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Extreme high-speed laser cladding (EHLA) was used to develop a pore- and crack-free TiC/IN625 coating. The surface roughness of EHLA could be as low as 6.004 µm. A more uniform dendrite size and composition distribution was obtained by EHLA. The mass gain of EHLA was 57.5% lower than that of the conventional laser cladding sample after hot corrosion in a mixed salt of 75%Na2 SO4 + 25% NaCl at 900 ℃ for 60 h. High hot corrosion resistance of EHLA was mainly attributed to the lower surface roughness, smaller dendrite size, smaller grain size, and higher amount of low-angle grain boundaries. Highlights: Pores- and cracks-free TiC/IN625 coatings over AISI 1045 steel were firstly prepared by EHLA. EHLA TiC/IN625 coatings possessed much more uniform and finer microstructure. The uniformly distributed dendrite sizes and compositions contributed to the formation of a dense oxide film. Superior hot corrosion behavior of EHLA TiC/IN625 coatings was mainly attributed to the lower surface roughness, smaller dendrite size, smaller grain size, and more low-angle grain boundaries.