METHOD OF MODIFYING HEAT-RESISTANT ALLOYS AND HIGH-ALLOY STEELS Russian patent published in 2019 - IPC C21C5/52 C21C7/06 B82Y30/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy and foundry production and can be used in machine building, automotive industry and tractor construction in production of high quality castings from high-alloy steels and heat-resistant alloys. Mixture of nano-sized powder modifiers is pre-compacted into groups of briquettes with different density and different porosity, wherein first group of briquettes is pressed with density greater than specific weight of liquid component of melt, corresponding to temperature of end of its crystallisation - solidus, second group - with density less than specific weight of liquid component of melt, which corresponds to temperature of crystallization beginning - liquidus, and intermediate groups of briquettes between them are pressed with porosity varying in each group with pitch from 5 to 10 %, Thereafter, the calculated amount of briquettes of said groups is fed into the melt for uniform distribution of nano-sized powder modifiers.

EFFECT: invention improves operational characteristics of casts due to use of differentiated by density briquettes with nanoparticles of modifiers, which leads to creation of finely dispersed structure of cast material.

1 cl, 5 dwg, 15 tbl, 3 ex