METHOD OF PRODUCING COLD-ROLLED SHEETS FROM SECONDARY ALUMINIUM ALLOY Russian patent published in 2024 - IPC C22F1/04 C22C21/00 B21B3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to deformable materials based on aluminium, and can be used in production of rolled sheets from secondary raw materials, intended for operation in a wide temperature range, up to 400 °C. In particular, rolled sheets can be used to produce articles for structural purposes, from which a combination of sufficient strength, heat resistance and low price is required. Method of producing a cold-rolled and annealed sheet from a secondary aluminium alloy involves obtaining a melt of a secondary aluminium alloy, obtaining a cast billet by crystallisation of the melt, deforming the cast billet to produce a sheet and annealing the obtained sheet. Melt of secondary aluminium alloy is formed on the basis of secondary raw material with provision of the following composition, wt.%: copper from 1.5 to 2.5, manganese from 1.3 to 2.0, iron from 0.2 to 0.6, silicon from 0.2 to 0.6, magnesium from 0.4 to 1.0, zinc from 0.4 to 1.5, aluminium – the rest. Cast billet is obtained during crystallisation at cooling rate of not less than 8 °C/s, deformation of cast billet is carried out by rolling at temperature from 400 to 460 °C with reduction of 60 to 90%, and then by rolling at room temperature with reduction of 60 to 90%. Annealing of cold-rolled sheet is carried out at temperature from 390 to 510 °C for 2 to 6 hours.

EFFECT: cold-rolled and annealed sheet has ultimate strength of at least 300 MPa, yield point of at least 200 MPa and relative elongation of at least 10%.

2 cl, 5 dwg, 3 tbl, 3 ex