Method of manufacturing an aluminium alloy rolled product

A method of manufacturing an aluminium alloy rolled product of a heat-treatable aluminium alloy having a thickness of at least 1 mm, comprising the steps of:

• (a) semi-continuous casting a heat-treatable aluminium alloy into a rolling ingot having a thickness of at least 250 mm;
• (b) preheating and/or homogenizing of the rolling ingot to a peak metal temperature (PMT) of less than 530°° C., wherein after said preheating and/or homogenizing the rolling ingot exhibits a specific energy associated with a Differential Scanning Calorimetry (DSC) signal less than 2 J/g in absolute value;
• (c) hot rolling of the rolling ingot in multiple hot rolling steps into a hot rolled product having a final rolling gauge of at least 10 mm, wherein hot rolling occurs in at least three hot rolling steps whereby the hot rolled product during at least one of the last three rolling steps has a temperature less than 50° C. below PMT (° C.);
• (d) quenching of the hot rolled product at final rolling gauge from hot-mill exit temperature to below 175° C.;
• (e) optionally stress relieving of the quenched and hot rolled product at final rolling gauge;
• and
• (f) ageing of the quenched and optionally stress relieved hot rolled product.