Process for preparing hard tempered aluminum alloy sheet

A process according to claim 13, wherein said rolling reduction is 70 to less than 85%.

A process for preparing a hard tempered aluminum alloy sheet from an aluminum base alloy consisting essentially of from about 4 to about 6 wt. % magnesium, at least one component selected from the group consisting of from about 0.1 to about 0.7 wt. % of manganese, from about 0.01 to about 0.05 wt. % of zirconium, from about 0.005 to 0.12 wt. % of vanadium and up to about 0.05 wt. % of titanium, and the balance aluminum, comprising the steps of:

• hot rolling an ingot of said aluminum base alloy to produce a sheet having a thickness of not more than 2.5 mm, said hot rolling step being performed so that the finishing temperature is from about 300 to about 350.degree. effective to recrystallize said alloy;
• and
• then effecting final cold rolling of said sheet at a rolling reduction of less than 85% to obtain a hard tempered aluminum alloy sheet having a 90.degree. earing ratio of more than 2% and a 45.degree. earing ratio of not more than 3.5% when the sheet is deep drawn.

A process for preparing a hard tempered aluminum alloy sheet from an aluminum base alloy consisting essentially of from about 4 to about 6 wt. % magnesium, at least one component selected from the group consisting of from about 0.1 to about 0.7 wt. % of manganese, from about 0.01 to about 0.05 wt. % of zirconium, from about 0.005 to 0.12 wt. % of vanadium and up to about 0.05 wt. % of titanium, and the balance aluminum, consisting essentially of the steps of:

• heating a homogenized ingot of said aluminum base alloy to a temperature of from about 460.degree. to about 540.degree. C. and then hot rolling said heated ingot to produce a sheet having a thickness of not more than 2.5 mm;
• then, without subjecting said sheet to a cold rolling step, heating said sheet at from about 300.degree. to about 350.degree. C. for about 1 hour to recrystallize said alloy;
• then effecting final cold rolling of said sheet at a rolling reduction of less than 85% and then heating said sheet at a temperature of not more than 250.degree. C. to stabilize the sheet and thereby obtaining a hard tempered aluminum alloy sheet having a thickness of less than about 0.4 mm, a 90.degree. earing ratio of from 5 to 6% and a 45.degree. earing ratio of not more than 3.5% when the sheet is deep drawn.

A process for preparing a hard tempered aluminum alloy sheet from an aluminum base alloy consisting essentially of from about 4 to about 6 wt. % magnesium, at least one component selected from the group consisting of from about 0.1 to about 0.7 wt. % of manganese, from about 0.01 to about 0.05 wt. % of zirconium, from about 0.005 to 0.12 wt. % of vanadium and up to about 0.05 wt. % of titanium, and the balance aluminum, consisting essentially of the steps of:

• hot rolling a homogenized ingot of said aluminum base alloy to produce a sheet having a thickness of not more than 2.5 mm, said hot rolling step being performed at a starting temperature of from about 460.degree. to about 540.degree. C. and a finishing temperature of from about 300.degree. to about 350.degree. C. during a time period of from 5 to 10 minutes so that said alloy is recrystallized;
• then effecting final cold rolling of said sheet at a rolling reduction of less than 85% and then heating said sheet at a temperature of not more than 250.degree. C. to stabilize the sheet and thereby obtain a hard tempered aluminum alloy sheet having a thickness of less than about 0.4 mm, a 90.degree. earing ratio of from 5 to 6% and a 45.degree. earing ratio of not more than 3.5% when the sheet is deep drawn.