1 School of Mechanical, Electronic and Control Engineering, Materials Science & Engineering Research Center, Beijing Jiaotong University, Beijing 100044, China 2 School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China 3 National Engineering Laboratory of Additive Manufacturing for Large Metallic Components, Beihang University, Beijing 100083, China 4 Hefei Innovation Research Institute of Beihang University, Hefei 230013, Anhui, China
Microstructural development and wear properties analyses of Fe-based coatings on bainitic steel by laser cladding
1 School of Mechanical, Electronic and Control Engineering, Materials Science & Engineering Research Center, Beijing Jiaotong University, Beijing 100044, China 2 School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China 3 National Engineering Laboratory of Additive Manufacturing for Large Metallic Components, Beihang University, Beijing 100083, China 4 Hefei Innovation Research Institute of Beihang University, Hefei 230013, Anhui, China
摘要 Wear-resistant Fe-based coating was prepared by high-speed laser cladding on bainitic steel. The influence of laser scanning speed on microstructure, microhardness, and wear resistance of cladding coating was investigated. Scanning electron microscopy results showed that the coating was mainly composed of dendrite and interdendrite. Scanning electron microscope images were converted by binary algorithm to facilitate statistics of dendrite and interdendrite area. Statistical results indicate that by accelerating the scanning speed, the interdendrite eutectic structure increased. According to energydispersive X-ray spectroscopy and X-ray diffraction results, the interdendrite was enriched with elements Cr, Mo, and B, and main structures in the coating were α-Fe, γ-Fe, and M23C6. The hardness of the coating was much higher than that of the substrate. Elements diffused from coating to substrate, resulting in a transition zone of hardness. Moreover, with an increase in the scanning speed, the diffusion of elements at the coating–matrix interface decreased, while the hardness and wear resistance of the coating increased. Grain refinement and interdendrite (γ-Fe, M23C6) increasing due to high scanning speed were the major contributors to the increase in hardness and wear resistance.
Abstract：Wear-resistant Fe-based coating was prepared by high-speed laser cladding on bainitic steel. The influence of laser scanning speed on microstructure, microhardness, and wear resistance of cladding coating was investigated. Scanning electron microscopy results showed that the coating was mainly composed of dendrite and interdendrite. Scanning electron microscope images were converted by binary algorithm to facilitate statistics of dendrite and interdendrite area. Statistical results indicate that by accelerating the scanning speed, the interdendrite eutectic structure increased. According to energydispersive X-ray spectroscopy and X-ray diffraction results, the interdendrite was enriched with elements Cr, Mo, and B, and main structures in the coating were α-Fe, γ-Fe, and M23C6. The hardness of the coating was much higher than that of the substrate. Elements diffused from coating to substrate, resulting in a transition zone of hardness. Moreover, with an increase in the scanning speed, the diffusion of elements at the coating–matrix interface decreased, while the hardness and wear resistance of the coating increased. Grain refinement and interdendrite (γ-Fe, M23C6) increasing due to high scanning speed were the major contributors to the increase in hardness and wear resistance.
Run-feng Peng,Min Zhang,Yu-hang Li, et al. Microstructural development and wear properties analyses of Fe-based coatings on bainitic steel by laser cladding[J]. Journal of Iron and Steel Research International, 2022, 29(4): 687-697.
2022, Vol. 29 
