To enhance the corrosion resistance of type C45E4 substrates, a superhydrophobic Ni-Co coating was prepared on a C45E4 surface by sandblasting pretreatment and electrodeposition. The surface microstructure, three-dimensional surface roughness, and crystal structure of the coating was characterized by scanning electron microscope, laser scanning confocal microscope, and X-ray diffraction. An optical surface contact angle measuring instrument and an electrochemical workstation was used to characterize the wettability and corrosion resistance of the surface. The results showed that the water contact angle reached 151.2 degrees on the Ni-Co coating surface. The surface was superhydrophobic and still had stable hydrophobicity after four months. In electrochemical corrosion experiments. Compared with polishing pretreatment, the corrosion current density of superhydrophobic Ni-Co coating prepared by sandblasting pretreatment reached I_corr = 5.05 × 10⁻⁷ A·cm⁻², and the corrosion potential reached E_corr = −0.33 V. The superhydrophobic Ni-Co coating had excellent corrosion resistance.

To improve the wear resistance of 45 steel surfaces, a Ni−P alloy coating was prepared on the surface of 45 steel with an immersion-assisted jet-electrodeposition technology. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and confocal microscopy were used in testing the surface morphology, composition, structure, grain size, and wear scar parameters of the coating. The effect of immersion-assisted jet-electrodeposition on the wear resistance of Ni−P alloy coating at current densities of 20–60 A·cm⁻² were explored and analyzed. Results showed that the surface quality, microhardness, and wear resistance of Ni−P alloy coatings prepared through immersion-assisted jet-electrodeposition were improved compared with those of the coatings prepared through traditional jet-electrodeposition. With the increase in the current density, the surface cell structure of the alloy coating was refined, the flatness was improved, the surface Ni content was increased, the grain size was refined, and the coating thickness, the microhardness, and wear resistance showed a trend of first increasing and then decreasing. The best surface quality of the coating was observed at a current density of 50 A·cm⁻². Moreover, the unit cell structure was obvious, the surface was flat and dense, the coating thickness was the largest, reaching 21.42 μm, the highest Ni content was obtained (98.25 wt.%), the smallest grain size (6.6 nm) was obtained, the microhardness of the coating reached a maximum value (725.58 HV_0.1), and the best wear resistance was observed.

This study aimed to investigate the wear failure changes of spindle hook teeth and the reasons for such failure during field work. Spindle samples were obtained from a fixed position of the spindle bar under different field picking area conditions and combined with the spatial distribution characteristics of cotton bolls in Xinjiang. After cutting a spindle sample, a scanning electron microscope and an energy spectrum analyzer were used to characterize the micromorphology and element composition of the hook tooth surface and cross section under different working area conditions. The wear parameters of the hook teeth were then extracted. The results showed that the thickness of the coating on the surface of the hook tooth used in this study was between 66.1 µm and 74.4 µm. The major chemical element was chromium, with a small amount of nickel. During the field picking process, failure of the coating on the surface of the hook teeth initially appeared on the tooth tip and tooth edge, and then spread to the entire hook tooth surface. The wear failure of the hook teeth resulted from abrasive wear, oxidative wear, and fatigue peeling. As the picking area increased, the wear area of the hook teeth increased exponentially, while the wear width increased linearly. When the field picking area reached 533.33 ha, the maximum change rate of the wear area was 2.33 × 10³ µm²/ha, and the wear width was 1.84 µm/ha. During field work, the thickness of the coating decreased from the cutting surface to the tooth edge, and the wear rate gradually increased. The wear rate at Position 1 was the slowest, at 0.01 µm/ha, and the wear rate at Position 5 was the fastest, at 0.25 µm/ha.

Ni-P-SiC composite coating was prepared on 45 steel surfaces through sandblasting and scanning electrodeposition to explore the relationship between element penetration region and composite coating properties. The single-factor control variable method with particle concentration as the research variable was used. Results showed that with the gradually increasing concentration of SiC nanoparticles, a trend of first increasing and then gradually decreasing was observed for the surface and cross-sectional microstructure of the coating, interpenetration ability of the elements, adhesion performance, and corrosion resistance. The best deposition quality of the coating was obtained when the concentration of SiC nanoparticles was 3 g·L⁻¹. For cross-sectional microstructure, the scratch test revealed that the maximum coating thickness was 17.3 μm, the maximum range of elemental penetration region was 28.39 μm, and the maximum adhesion of the composite coating was 36.5 N. The electrochemical test showed that the composite coating had a −0.30 V self-corrosion potential and 8.45 × 10⁻⁷ A·cm⁻² self-corrosion current density, the slowest corrosion rate. In addition, the composite coating had the best corrosion resistance and the largest impedance arc radius corresponding to an equivalent impedance value R₂ of 3108 Ω.

In this study, Ni–P/Ni–P–SiC coatings were prepared on pretreated 45 steel substrates by scanning electrodeposition. Prior to the electrodeposition, the substrates were subjected to two types of pretreatments: polishing and sandblasting. The 3D morphology of the pretreated substrates was characterized by laser scanning confocal microscopy. The micromorphology and section morphology of the coating surface were characterized by field emission scanning electron microscopy. The section element composition was characterized using an EDS energy spectrum analyzer. The adhesion and corrosion resistance of 15 coatings were analyzed using an automatic scratch tester and CS350 electrochemical workstation. The results showed the presence of an element penetration region between the coating and the substrate. The sandblasting pretreatment and SiC nanoparticle addition helped widen the penetration region of the elements. The Ni–P–SiC coating prepared by scanning electrodeposition on the sandblasted substrate exhibited the thickest penetration region, up to 28.39 µm. A scratch test conducted on this coating showed that it exhibits the best adhesion force, up to 36.5 N. In electrochemical corrosion experiments, its corrosion potential was found to be the highest, reaching −0.30 V, and the corrosion current density was the lowest, reaching 8.45 × 10⁻⁷ A·cm⁻². The presence of the element penetration region increased the coating adhesion and improved the corrosion resistance.