無鋳型引き上げ連鋳法による異形断面形状アルミニウム合金棒材の製造

抄録

A production method of aluminum alloy profile rods by the moldless upward continuous casting process using formers was studied. Effects of the composition and the superheat of molten alloy, the withdrawal speed, and the size of the nozzle made in the former, on the ratio of strand formation (the ratio of the size of the cast strand to the size of the former nozzle, %), the sectional configuration, the macrostructure, the microstructure, and the surface conditions of the cast rod obtained were examined at a constant intensity of the strand cooling. Aluminum alloy profile rods having similar configurations to those of former nozzles and longitudinal tapers can be produced. The former nozzle determines the configuration of the molten alloy pillar formed on withdrawing upwardly. The square or asterisk cast rod is composed of columnar grains grown completely in the longitudinal direction. The ratio of strand formation is governed by the combination of the composition and the superheat of the molten alloy, the size of the former nozzle, and the withdrawal speed. The alloy profile rod having no longitudinal taper can be produced most easily under the condition where the ratio of strand formation is around 85∼95%.