Effect of homogenisation cooling rate and press exit temperature on extrudability and T5 hardness of EN AW 6082 alloy

Abstract

The effect of the homogenisation cooling rate on the extrudability of the soaked billet and of the press exit temperature on the age hardening capacity of the EN AW 6082 extrudates were investigated. The cooling rate in the range of 1000–150°C h⁻¹ does not impact the T5 temper hardness owing to the propensity of dispersoids, which encourage precipitation already at 1000°C h⁻¹. The press exit temperature has to be at least 500°C to ensure adequate hardening upon an artificial aging treatment. The reheating temperature to achieve a press exit temperature of 500°C, 460°C, does not lead to a measurable solution hardening. This is a further advantage from the extrudability standpoint.