Comparative Study on the Microstructure and Properties of Co-based and Ni-based Coatings Prepared by Laser Cladding
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摘要: 为了验证采用无钴镍基涂层替代钴基涂层的可行性，采用激光熔覆工艺分别制备了Ni55镍基涂层和Stellite 6钴基涂层。通过组织观察、硬度分析、摩擦磨损测试和电化学腐蚀测试，对比研究了两种涂层在组织结构及磨损性能和腐蚀性能方面的优劣。结果表明，Ni55镍基涂层的稀释率略大，组织大部分为等轴晶，而Stellite 6钴基涂层则为平行热流方向生长的树枝晶。Ni55镍基涂层的平均硬度为527 HV，大于Stellite 6钴基涂层的448 HV。摩擦磨损实验结果显示，室温下Ni55镍基涂层的摩擦系数和磨损失重均小于Stellite 6钴基涂层；300℃下Ni55镍基涂层虽然摩擦系数略大于Stellite 6钴基涂层，但磨损失重和磨损体积均小于Stellite 6钴基涂层。电化学腐蚀实验结果显示，Ni55镍基涂层的耐腐蚀性能更优。因此，镍基系列涂层有望替代Stellite 6钴基涂层用于核反应堆设备钩爪等耐磨零件。Abstract: To verify the feasibility of replacing Co-based coatings with Ni-based coatings, laser cladding was used to prepare Ni55 Ni-based coatings and Stellite 6 Co-based coatings. The study compared the advantages and disadvantages of the two coatings in terms of microstructure, wear resistance, and corrosion resistance through observations of microstructure, hardness analysis, friction and wear testing, and electrochemical corrosion testing. The results showed that the dilution rate of the Ni55 coating was slightly higher, and the microstructure was mostly isometric crystal, while the Stellite 6 coating had dendritic crystal growing parallel to the heat flow direction. The average hardness of the Ni55 coating was 527 HV, higher than the 448 HV of the Stellite 6 coating. The friction and wear test results showed that the friction coefficient and wear loss weight of the Ni55 coating were both lower than those of the Stellite 6 coating at room temperature. At 300 ℃, the friction coefficient of the Ni55 coating was slightly higher than that of the Stellite 6 coating, but the wear loss weight and wear volume were both lower. The electrochemical corrosion test results showed that the Ni55 coating had better corrosion resistance. Therefore, the Ni55 coating has the potential to replace the Stellite 6 coating for the drive mechanism wear-resistant parts such as hook claws of the nuclear reactor control rod.
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Key words:
- Laser cladding /
- Ni-based alloy /
- Co-based alloy /
- Friction and wear /
- Electrochemical corrosion
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图 1 Stellite 6钴基和Ni55镍基粉末的形貌
Figure 1. Morphology of Stellite 6 Co-based and Ni55 Ni-based Powders
图 3 涂层中部及界面处的金相组织
Figure 3. Metallographic Structure of the Coating at the Center and Interface
图 4 Stellite 6钴基涂层的SEM图及EDS面扫图
Figure 4. SEM Image and EDS Mapping of the Stellite 6 Co-based Coating
图 5 Ni55镍基涂层的SEM图及EDS面扫图
Figure 5. SEM Image and EDS Mapping of the Ni55 Ni-based Coating
图 7 常温下涂层和母材的摩擦系数
Figure 7. Friction Coefficient of Coatings and Substrate under Low Temperature
图 10 涂层的OCP及动电位极化测试曲线
Figure 10. OCP and Potentiodynamic Polarization Test Curves of Coatings
图 11 涂层的EIS图
Rs—电解液面电阻；Rf—钝化膜面电阻；Rct—电荷转移面电阻； Qdl—双电层非理想电容密度；Qf—钝化膜非理想电容密度。
Figure 11. EIS of Coatings
表 1 Stellite 6钴基粉末和涂层的成分（%，质量百分数）
Table 1. Composition of Stellite 6 Co-based Powder and Coating
样品形态 C Cr W Ni Mo Mn Si Fe Co 粉末 0.977 28.11 4.99 1.83 0.28 0.22 0.77 2.46 余量 涂层 0.899 29.12 5.11 2.01 0.25 0.33 0.91 2.62 余量 
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表 2 Ni55镍基粉末和涂层的成分（%，质量百分数）
Table 2. Composition of Ni55 Ni-based Powder and Coating
样品形态 C B Si Cr Fe Ni 粉末 0.477 1.61 3.53 14.31 2.49 余量 涂层 0.429 2.84 3.63 15.52 2.65 余量
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表 3 激光熔覆实验工艺参数
Table 3. Laser Cladding Process Parameters
工艺参数 参数值 激光功率/W 1500 光斑直径/mm 5.0 扫描速度/(mm·s−1) 4 保护气体流量/(L·min−1) 10 送粉速率/(g·min−1) 16 搭接率/% 50
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表 4 图5中各点的EDS点扫结果（%，质量百分数）
Table 4. EDS Point Scan Results in Fig. 5
位置 B C Si Cr Fe Ni P1 4.48 8.77 0.26 56.85 16.11 13.54 P2 7.40 6.09 2.32 3.90 13.35 66.93 P3 1.11 3.98 3.10 7.86 21.00 65.95
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表 5 稳态OCP及从极化曲线中拟合出的电化学参数
Table 5. Steady-state OCP and Electrochemical Parameters Fitted from Potentiodynamic Polarization Curves
材料 OCP /V 腐蚀
电位/V腐蚀电流
密度/(nA·cm−2)点蚀
电位/VStellite 6钴基 −0.235 −0.233 68.8 0.724 Ni55镍基 −0.201 −0.171 64.3 0.812
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表 6 EIS的拟合参数
Table 6. Fitting Parameters of EIS
材料 Rs/
(Ω·cm2)Qdl/
(μF·cm−2)ndl Rct/
(Ω·cm2)Qf/
(μF·cm−2)nf Rf/
(Ω·cm2)Stellite 6
钴基12.8 9.40 0.88 1.61×105 13.5 0.92 2.51×105 Ni55
镍基19.6 3.21 0.76 2.66×105 9.82 0.91 2.17×105 ndl—双电层非理想电容弥散指数；nf—钝化膜非理想电容弥散指数。
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[1] 刘彬,王银宏,王臣,等. 中国钴资源产业形势与对策建议[J]. 资源与产业,2014, 16(3): 113-119. [2] OCKEN H. Reducing the cobalt inventory in light water reactors[J]. Nuclear Technology, 1985, 68(1): 18-28. doi: 10.13182/NT85-A33563 [3] XU G J, KUTSUNA M, LIU Z J, et al. Characteristics of Ni-based coating layer formed by laser and plasma cladding processes[J]. Materials Science and Engineering: A, 2006, 417(1-2): 63-72. doi: 10.1016/j.msea.2005.08.192 [4] LIU X B, FU G Y, LIU S, et al. High temperature wear and corrosion resistance of Co-free Ni-based alloy coatings on nuclear valve sealing surfaces[J]. Nuclear Engineering and Design, 2011, 241(12): 4924-4928. doi: 10.1016/j.nucengdes.2011.09.021 [5] WU W H, ZHANG C, WANG R D, et al. A high temperature wear-resistant Ni-based alloy coating for coppery blast furnace tuyere application[J]. Surface and Coatings Technology, 2023, 464: 129550. doi: 10.1016/j.surfcoat.2023.129550 [6] BEHERA A, SAHOO A K. Wear behaviour of Ni based superalloy: a review[J]. Materials Today: Proceedings, 2020, 33: 5638-5642. doi: 10.1016/j.matpr.2020.04.007 [7] DEODESHMUKH V, GLEESON B. Evaluation of the hot corrosion resistance of commercial β-NiAl and developmental γ′-Ni3Al+ γ-Ni-based coatings[J]. Surface and Coatings Technology, 2007, 202(4-7): 643-647. doi: 10.1016/j.surfcoat.2007.06.018 [8] HU Y J, WANG Z X, PANG M. Effect of WC content on laser cladding Ni-based coating on the surface of stainless steel[J]. Materials Today Communications, 2022, 31: 103357. doi: 10.1016/j.mtcomm.2022.103357 [9] CHEN C, MEIPING W, RUI H, et al. Understanding Stellite-6 coating prepared by laser cladding: convection and columnar-to-equiaxed transition[J]. Optics & Laser Technology, 2022, 149: 107885. [10] ZHAO Y, FENG K, YAO C W, et al. Microstructure and tribological properties of laser cladded self-lubricating nickel-base composite coatings containing nano-Cu and h-BN solid lubricants[J]. Surface and Coatings Technology, 2019, 359: 485-494. doi: 10.1016/j.surfcoat.2018.12.017 -
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