The Preparation, Microstructure, and Wet Wear Properties of an Fe55-Based Welding Layer with the Co-Addition of 0.01 wt% CeO2 and 1.5 wt% SiC Particles Using the Plasma Beam Spraying Method

Liang Yu; Fuming He; Xinbin Liu; Yanli Jiang; Mengmeng Sui; Xiuling Cao; Zhengbing Meng

doi:10.3390/ma16237439

The Preparation, Microstructure, and Wet Wear Properties of an Fe55-Based Welding Layer with the Co-Addition of 0.01 wt% CeO₂ and 1.5 wt% SiC Particles Using the Plasma Beam Spraying Method

Materials (Basel). 2023 Nov 29;16(23):7439. doi: 10.3390/ma16237439.

Authors

Liang Yu^{1

2

3}, Fuming He¹, Xinbin Liu⁴, Yanli Jiang^{1

2

3}, Mengmeng Sui¹, Xiuling Cao^{5

6}, Zhengbing Meng^{1

2

3}

Affiliations

¹ Key Laboratory of New Processing Technology for Nonferrous Metals & Materials, Guilin University of Technology, Guilin 541004, China.
² Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of Resources, Guilin University of Technology, Guilin 541004, China.
³ Guangxi Modern Industry College of Innovative Development in Nonferrous Metal Material, Guilin University of Technology, Guilin 541004, China.
⁴ School of Intelligent Manufacturing and Mechanical Engineering, Hunan Institute of Technology, Hengyang 421002, China.
⁵ Hebei Technology Innovation Center for Intelligent Development and Control of Underground Built Environment, Shijiazhuang 050031, China.
⁶ School of Exploration Technology and Engineering, Hebei GEO University, Shijiazhuang 050031, China.

Abstract

Severe erosion wear is found on valve spools, which threatens the safety and reliability of these units. The use of the plasma beam spraying surfacing method can significantly improve the corrosion resistance and sealing performance of hydraulic valve spools, reduce material waste, and reduce maintenance costs. The effects of the co-addition of CeO₂ and SiC particles on the morphology, surface cracks, microstructure, precipitated phases, and wear property of plasma-beam-sprayed Fe55-based coatings on 1025 steel were investigated using OM, EDS, ultra-deep field microscopy, and a wet sand rubber wheel friction tester, respectively. The dendrite exhibited a directional growth pattern perpendicular to the substrate and the transitional states of the microstructure with the co-addition of CeO₂ and SiC particles. CeO₂ or SiC reduced the liquid phase diffusion coefficient D_L of Cr and C and resulted in a decrease in the G/R ratio. The dendrites changed into equiaxed grains. The main phase composition of the Fe55 welding layer was Cr₇C₃, γ-Fe. The martensite in the surfacing layer and the carbides formed Cr₇C₃, which can improve the hardness of the surfacing layer. The grain boundaries consisted mainly of a reticular eutectic structure. The uniform distribution of the Cr₇C₃ hard phase in the Fe55+1.5 wt% SiC+0.01 wt% CeO₂ resulted in a uniformly worn surface. The sub-wear mechanisms during the friction process were micro-ploughing and micro-cutting. The hardness and toughness of Fe55+1.5 wt% SiC+0.01 wt% CeO₂ were well-matched, avoiding excessive micro-cutting and microplastic deformation. A low content of CeO₂ could lead to the formation of equiaxed grain and effectively improve the uniformity of the microstructure. The wear-resistant layer of Fe55+1.5 wt% SiC+0.01 wt% CeO₂ can effectively improve the service life and long-term sealing performance of the valve spools.

Keywords: CeO2; co-addition; microstructure; plasma beam spraying method; wear performance.

Grants and funding

The work was supported by the Scientific Research Program of Hunan Department of Education 19A126, the open fund of the Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, the Ministry of Education/Guangxi Key Laboratory of Optical and Electronic Materials and Devices (22AA-11 and No. 20KF-4), the Guangxi Science and Technology Planning Project (Grant No. AA22067079-1), and the Foundation of Introduction of Senior Talents in Hebei Province (H192003015).