| 摘要 |
The present invention relates to a method of producing a high damage tolerant aluminium alloy rolled product a high toughness and an improved fatigue crack growth resistance, including the steps of: a.) casting an ingot having a composition selected from the group comprising AA2000, AA5000, AA6000, and AA7000-series alloys; b.) homogenising and/or pre-heating the ingot after casting; c.) hot rolling the ingot into a hot rolled product and optionally cold rolling the hot rolled product into a cold rolled product, wherein the hot rolled product leaves the hot rolling mill at an hot-mill exit temperature (T<SUB>Exit</SUB>) and cooling the hot rolled product from the T<SUB>Exit </SUB>to 150° C. or lower with a controlled cooling cycle with a cooling rate falling within the range defined by: T(t)=50-(50-T<SUB>Exit</SUB>)e<SUP>alphat </SUP>and wherein T(t) is the temperature (° C.) as function in time (hrs), t is the time (hours) and alpha is in the range of -0.09±0.05 (hrs<SUP>-1</SUP>).
|
