Fastening hardware is subject to corrosion on account of chemical, electrochemical, or biochemical reactions with the surroundings. We know that around a tenth of the annual production of metal is consumed in replacing corrosion losses. Zinc plating (by galvanization, immersion in melt, or thermodiffusion) is widely used to protect fastening hardware from corrosion [1]. Disadvantages of galvanization include the long duration of the process and the very low corrosion resistance of the hardware. In hot zinc plating, it is difficult to obtain a uniform coating on threaded parts. Diffusional zinc plating yields uniform layers on hardware of various types, but its widespread industrial use is limited by the duration of the process and its instability, associated with the sintering of saturating powder. Rotating retorts are used to accelerate diffusional saturation, but the process is still lengthy. The use of a fluidized bed is a more promising means of intensifying chemicothermal treatment [2]. To increase the corrosion resistance, diffusional zinc coatings are alloyed with aluminum, magnesium, titanium, and copper [1].
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