| DONG Hui,GUO Peng-fei,XU Long,KANG Kai-xiang.Effect of Heat Treatment Temperature on Microstructure and Friction and Wear Properties of High-speed Laser Cladded Ni/316L Coating[J],51(5):111-120 |
| Effect of Heat Treatment Temperature on Microstructure and Friction and Wear Properties of High-speed Laser Cladded Ni/316L Coating |
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| DOI：10.16490/j.cnki.issn.1001-3660.2022.05.012 |
| KeyWord:heat treatment high-speed laser cladding Ni/316L coating marine environment friction and wear |
| Author | Institution |
| DONG Hui |
Xi'an Key Laboratory of High Performance Oil and Gas Field Materials, School of Material Science and Engineering, Xi'an Shiyou University, Xi'an , China |
| GUO Peng-fei |
Xi'an Key Laboratory of High Performance Oil and Gas Field Materials, School of Material Science and Engineering, Xi'an Shiyou University, Xi'an , China |
| XU Long |
Xi'an Key Laboratory of High Performance Oil and Gas Field Materials, School of Material Science and Engineering, Xi'an Shiyou University, Xi'an , China |
| KANG Kai-xiang |
Xi'an Key Laboratory of High Performance Oil and Gas Field Materials, School of Material Science and Engineering, Xi'an Shiyou University, Xi'an , China |
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| Abstract: |
| The effect of heat treatment temperature on the wear resistance of high-speed laser cladded Ni/316L coatings in seawater corrosive environment was illustrated in this case. Ni/316L coatings were prepared on the surface of Q235 steel by high-speed laser cladding equipment, and heat-treated at 650, 700, 750 ℃, and 800 ℃ for 1.5 h, respectively. X-ray diffraction (XRD), scanning electron microscope (SEM) The microstructure and phase composition of the Ni/316L cladding layer were characterized by energy dispersive spectrometer (EDS). In addition, the effect of heat treatment temperature on the hardness and the wear resistance of the Ni/316L cladding layer was analyzed via hardness test and wear test in a simulated marine environment. The thickness of as-cladded layer is about 2 mm, and the transition layer is about 50 μm. The cladding layer has the characteristics of compactness, low porosity and crack free. The cladding coating grains contain dendrites and equiaxed grains. With the increase of heat treatment temperature, the number of equiaxed crystal in the coating first increased and then decreased, similar to that of the new phase content, the second phase content first increased and then decreased. Correspondingly, as the heat treatment temperature increased, the grain size of the cladding layer decreased first and then increased, resulting in the hardness of the cladding layer increased first and then decreased. The hardness of the cladding layer reached the highest value at 750 ℃, which was about 2.4 times that of the as-cladded coating. It was found that the friction coefficient of the four cladding layers after heat treatment is about 0.31, which is slightly lower than that of the cladding coating (0.33). The wear rate of the as-cladded coating was about 5 times higher than that of the coating heat-treated at 750 ℃. Under the high load of 200 N, the coating surface was plastically deformed, and the wear debris and particles after cutting enter into the sliding friction, resulting in cutting effect intensified, forming a valgus morphology caused by furrows and plastic deformation. The seawater is corrosive, and the stainless steel coating first forms a passivation film in seawater, which will be destroyed and will intensify corrosion and lead to crack expansion. On the other hand, the resistance of GCr15 steel in seawater the corrosion resistance is poor. The products after rapid corrosion formed abrasive particles during sliding friction, which enter the coating and the friction pair to produce three-body wear. As a result, the particles has a continuous cutting effect on the cladding layer. 5 kinds of coatings wear mechanisms are mainly the abrasive wear. The four different heat treatment processes all could improve the wear resistance of the cladding layer, while C shows a better wear resistance. The°the coating heat-treated at 750 ℃microstructure and the number of second phases of the high-speed laser cladding Ni/316L coating changes with the heat treatment temperature. However, the high temperature leads to some problems, such as grain growth. Therefore, the heat treatment temperature of the high-speed laser cladding Ni/316L coating should be controlled below 750 ℃. |
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