Mezentseva I. Reprocessing of nickel-containing wastes by metallurgic method to obtain complex alloy admixtures

The thesis deals with the development of basics of production by metallurgical methods of nickel-containing foundry-alloy for micro alloying pig- iron instead of conventionally used ferrous alloys by means of utilizing wastes produced at machine-building plants. On the basis of the conducted analysis of structural and phase terms of wastes of electro-erosion treatment of machine-parts containing nickel alloys a new high-temperature process of carbon-thermal regeneration has been proposed. Fractural-and-factorial experiment has been conducted to determine the optimal conditions for obtaining regenerated product. Thus obtained complex alloy contains up to 60% of nickel, 15% of chromium, as well as tungsten, molybdenum and titanium. The model of physical-mechanical interrelations taking place at the regenerating process of wastes of electro-erosion treatment on the basis of method of local thermodynamic balance has been developed. It has been established that the leading role in the process of regeneration is taken by carbon and ferric carbide; also the mechanism of metallic term formation has been shown. There has been outlined ecological and economic effect of using the obtained complex admixture instead of conventionally used ferroalloys for gray cast iron's alloyage. While alloying gray cast iron there has been conducted the substitution of traditionally used ferrochrome and iron nickel by the obtained complex admixture.