Influence of rolling and annealing modes on properties of semi-finished sheet products made of aluminum deformable alloy 1580

Abstract

The study covers the manufacturability and properties of sheet metal obtained from a large-sized ingot of Alloy 1580 with the low scandium content within its grade range. The ingot processability in hot and cold rolling was evaluated, and the influence of the degree of deformation and annealing conditions on the properties of cold-rolled semi-finished products made of the alloy under study was investigated. A large-sized commercially produced ingot with a cross section of 500×2100 mm of Alloy 1580 with a scandium content of 0.067 wt.% was selected as an object of research. The research methodology included several stages of rolling and heat treatment of semi-finished sheet products at various stages of the developed mode for metal deformation and mechanical testing of samples from them on the LFM 400 kN universal machine. For research, a 60×500×900 mm template was cut from the ingot to make 50×180×300 mm billets for rolling. Billets were subjected to homogenization annealing by the two-stage mode developed previously for this alloy. As a result of hot rolling of annealed billets at 450 °C and a total relative compression e Σ = 84÷90 %, 5–8 mm thick semi-finished sheet products were obtained. Further, after their annealing at t = 320 °C for 6 hours, light-gauge semi-finished sheet products with a thickness of 2 to 6 mm were manufactured by cold rolling. They were subjected to mechanical analysis in the deformed and annealed states. The analysis of their mechanical properties in the deformed and annealed states was performed, which showed that the accumulation of the total degree of deformation during cold rolling up to 38 % provides the 1580 alloy with an increase in strength properties to R p = 380 MPa, and after that the growth rate slows down and at e Σ = 60 % R p = = 400 MPa. The effect of annealing at temperatures between 250 °C and 350 °C on the mechanical properties of sheet metal. It was found that it leads to a decrease in strength properties and an increase in ductility, and the maximum yield strengths correspond to annealing temperatures of 250–275 °C at a sufficiently high plasticity. As a result of studies, it was found that the strength properties of sheet metal from Alloy 1580 with a low scandium content exceed the strength properties of semi-finished products of Alloy AW-5083 (USA) having a similar chemical composition, but without the addition of scandium, by 10–15 %, and the excess in plastic properties is 40–60 %.