A theoretical analysis of the influence of carbon content in the steel and nature of macrostructure on segregation of impurities in the crystallization process were made. It is shown that increase of carbon content and transgranular macrostructure creation degree of segregation is being increased. A comparison of sulfur segregation in the ingot with equiaxial and transgranular structure was carried out and the theoretical points were confirmed.

The article presents the waste generated during the production of hot‑dip galvanizing. The results of the study of the particle size distribution of zinc dust showed that its particle size distribution in the size range of particles ≤ 250 μm, the proportion of which is 87 wt.%, corresponds to the fractional composition of standard powder zinc. In ash, the number of particles up to 250 microns in size is approximately 35 wt.%. Studies of the chemical and phase composition of the hot‑dip galvanized waste – zinc dust made it possible to establish that the zinc content of the waste approximately corresponds to powder zinc (GOST 12601). The proportion of pure zinc in dust is 95 %. Chemical and phase analyzes of the ash have shown that it contains zinc oxides, pure zinc and zinc chlorides. Zinc chlorides, in turn, can be a supplier of chlorine ions in thermal diffusion galvanizing. In this regard, it is of interest to use ash in the composition of the powder composition as an activating and zinc‑containing component. The results of the analysis of the conducted studies of hot‑dip galvanizing wastes – zinc dust and soot show that they are promising for their use as components in saturating mixtures in the production of zinc coatings by chemical‑thermal treatment. This will reduce the cost of galvanized products and ensure the recycling of zinc into industrial circulation.

The chemical and grain-size analysis of zinc dust – waste of hot – dip zinc plating were made. The research results showed that zinc dust is a dispersed waste with particles of mainly circular shape and sizes from 3 to 200 microns, and in chemical composition it mainly meets the requirements of ISO 3549. The presence of lead in the zinc dust composition, which is slightly higher than the acceptable level will be taken into account in the development of zinc-rich paints compositions. Analysis of the results of sieving of zinc dust showed that it contains particles of size £15 µm, which is about 27% of its fractional composition and which can be recommended for the manufacture of zinc-rich paints.

It is established that inclusion of the modifier into the electrode coating allowed to change the grains of the weld metal from 20–60 to 10–30 mm, to change its morphology and to improve the welding-technological properties of the coated electrode. It is shown that the modifying additive introduced into the coating of a welding electrode containing ultrafine particles in an amount of 1% of the weight of the dry charge had not deteriorated the technological parameters during manufacture, and the integral index of the different thickness (Desp) of electrodes with standard and experimental coatings did not add to the accepted value of 0.05. This indicates that the quality of the lubricating mass, its properties, the stability of the mass flow from the spinneret are satisfactory for both batches.

A comparative analysis of the corrosion properties of zinc-containing coatings obtained on the basis of metallic powder zinc and dispersed hot-dip galvanized waste has been carried out. The results of a study of the corrosion resistance of zinc-containing coatings by the electrochemical method and in a salt spray chamber have shown that coatings obtained on the basis of dispersed hot-dip galvanized waste are not inferior in protective properties to coatings based on powder standard zinc.