DE2008918A1 - A1-mn alloy strip production - Google Patents

Abstract

alloy strip in the (semi-)hard condition is produced by (1) heat treating the billet at 350-550 degrees C for 2 hrs. after its homogenising treatment; (2) heating the strip after rolling down to an intermediate thickness to 400-600 degrees C at >=100 degrees C/min.; (3) maintaining at 300-500 degrees C for 10 mins. - 16 hrs. Strip has improved deep drawing properties and less earing.

Description

Process for the production of semi-hard thin strips from aluminum-manganese alloys The subject of the application is a method for producing strips from the alloy AlMn in the state "semi-hard" to "hard" and with tip heights below 3% (so-called Tapes).

For the purpose of manufacturing deep-drawn parts such as bottle caps and can lids, thin strip made of the alloy AlMn according to DIN 1725 is suitable because of its generally good deep-drawing properties very well. The strength properties should correspond to the condition "semi-hard" to "hard" according to DIN 1745 and the The tip height should be less than 3, often less than 1% (see Aluminum Pocket Book, 12. Edition, p. 221 and 392j Aluminum-Verlag Düsseldorf, 1963).

However, the manufacture of such a material is still with one relatively high manufacturing costs associated. So it is known to have tapes with the above to produce the specified properties according to the following operation: 1. Hot rolling the rolling ingot into hot rolled strip 2. Cold rolling with a degree of deformation of 50-70 KWG 3. Recrystallizing intermediate annealing 4. Cold rolling with one degree of deformation from 50-70 KWG 5. Rocrystallizing intermediate annealing 6. Cold rolling to produce the semi-hard state.

Rolling on modern strip rolling lines is very economical as long as it is not interrupted by intermediate anneals. The conditions of the semi-hard State and the tip height below 5 can, however, without a single intermediate annealing generally not achieve.

Surprisingly, however, it turned out that it is possible with one get by with a single intermediate glow, if you combine three special Applies procedural steps. According to the method according to the invention is the production of semi-hard, thin AlMn strips with tip heights below 1% and with only one annealing of the rolled strip is possible with the following steps: 1. Annealing the rolling ingot (homogenizing) at 580-6400C, for 4 to 48 hours 2. Cooling the rolling billets to a temperature between 350 and 5500C, preferably 4500C 3. Annealing at this temperature at least 2 Allowed, preferably 12 hours 4. Hot rolling of the billet from the annealing heat a hot rolling band 5. cold rolling the hot rolled strip to a thickness that after Annealing is necessary to make the semi-hard one by rolling to the desired final thickness Condition to get 6. Heating of the strip for recrystallizing annealing Temperatures between 400 and 6000C, preferably 5000C, with a heating rate of 1000C / min or higher, preferably 2500C / min 7. Annealing of the strip after heating at temperatures between 300 and 6000C, preferably 500 ° C, 10 Minutes to 16 hours, preferably 1 hour 8. Finish rolling the strip on Final thickness.

The combination is essential for the process according to the invention of steps 3, 6 and 7. Accordingly, it is characterized in that a) the Rolling ingots following the homogenization annealing and annealing at temperatures between 350 and 5500C for a period of at least 2 hours, b) the on an intermediate thickness of rolled strip for recrystallizing annealing at temperatures heated between 400 and 600 ° C at a rate of at least 100 ° C / min will; c) the tape after heating up to temperatures between 300 and 5000C 10 is annealed for htmin to 16 hours.

The importance of the essential for the process according to the invention Steps should be explained from test results: A. Put an AlAIn tape with a final thickness of 0.23 now according to the method according to the invention one has a tip height ZH = 1, O.

B. If you do not anneal the rolling ingot according to the proposed according to the invention Process steps 2 and 3, but cools down to 5300C after homogenization and then hot rolling, one obtains tip heights Zil = 4Z on the finished strip.

C. If the belt is heated to temperatures between 400 and 6000C for recrystallizing annealing not at a heating rate of 1000C / min or more, but with 50 ° C / hour, then you get the finished band Point heights Zil = 6%.

D. If the proposed according to the invention after heating the tape Annealing between 300 and 6000C is not carried out and is immediately cooled again, one obtains tip heights ZII = 5%.

Claim:

Claims (1)

P a t e n t a n s p r u c h: Procedure for the liers leaning of ligaments from the alloy Allen in the condition "semi-hard" to "hard" and with peak heights below 3 (lobed strips), d a cl u r c h e k e n n z e 1 c h n e t that a) the rolling ingot following the homogenization annealing, an annealing at temperatures between Is subjected to 350 and 5500C for at least 2 hours; b) that on an intermediate thickness rolled strip for recrystallizing annealing at temperatures between 400 and 6000C is heated at a rate of at least 1000C / min; c) that Tape after heating up to temperatures between 300 and 5000C 10 minutes to 16 Is annealed for hours.