DE2712738A1 - PROCESS FOR MANUFACTURING SHEET METALS AND STRIPS FROM A ZINC ALLOY - Google Patents

Description

Rhenish zinc rolling mill 03/17/1977

GmbH & Co., limited partnership -DrQ / GKp-

Bahnhofstrasse 90, 4354 Datteln

Prov. No. 805 7 RZW

-z-

Process for the production of sheets and strips from a zinc alloy

The invention relates to a method for producing durable, Can be folded without breakage by 180 and is cold-formable, made of a zinc alloy with a copper content of 1.5 to 5.5% by weight and titanium from 0.05 to 0.25% by weight and optionally of aluminum from 0.005 to 0.05% by weight, the remainder zinc, existing sheets and strips in one operation by continuous casting and rolling, adding a 0.6 Cast tape up to 2.4 cm thick uniformly solidified and then in at least three, preferably five, stitches each with a cross-sectional decrease of

up to 80% according to patent (patent application

P 25 10 985.7) is finish-rolled hot.

In this patent (patent application P 25 10 985.7)

is to improve the deep-drawability of the sheets made from the zinc-copper-titanium alloy mentioned and tapes provided that the per unit time solidify

3
Melt volume is kept constant at 900 cm based on 1 cm cast strip width. The solidified cast strand which exits at a temperature from 120 to 400 ⁰ C from the strip casting machine is subsequently, finish hot rolled stitches at a temperature of 100 to 350 C in at least three, preferably five.

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The sheets and strips produced by means of these procedural measures have a fatigue strength: from 60 to

80 N / mm for 1% elongation / year, a break-free foldability by 180 ° according to DIN 1623 and a cold formability suitable for practice, as can be seen from the diagram in the diagram shown limit deformation curve A for the zinc alloy with 1.7% copper, 0.06% titanium and 0.01% Aluminum made sheets results.

The deformation limit curve was described in accordance with that from the magazine Bänder, Bleche, Rohr 10, 1974, pages 407-412 Procedure determined.

The increasing demands of consumers with regard to an improvement in the quality of the zinc-copper-titanium alloy produced sheets and strips, in particular with the aim of improved cold formability, were the reason for further development work.

It was found that the cold formability of the Zinc-copper-titanium alloy mentioned at the outset can be increased if, according to the invention, the solidified per unit of time Melt volume with a value of 250 to less than 900 cm per 1 cm of cast strip width is constant and the

solidified cast strand according to the patent

(Patent application P 25 10 985.7) described process measures is rolled down to the final dimension.

In the context of the preferred embodiment of the method according to the invention, that is that which solidifies per unit of time Melt volume with a value of 250 to 850 cm, in particular 600 to 850 cm, per 1 cm of cast strip width constant.

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For a more detailed explanation of the method according to the invention, the pearlitic zinc alloy with 1.7% copper, 0.06% titanium and 0.01% aluminum, the remainder zinc, at a temperature of 5 2O ° C on a strip casting machine for

3 aiming for a constant melt volume of 600 cm per 1 cm cast strand width to a cast strand 0.6 cm thick at a speed of 1,000 cm / min, to one Cast strand 1.8 cm thick at a speed of approx. 330 cm / min and into a cast strand 2.4 cm thick cast at a speed of 250 cm / min.

In order to obtain a constant melt volume of 850 cm per 1 cm of cast strip width, a cast strand of 0.6 cm was used Thickness at a speed of about 1,420 cm / min, a cast strand 1.8 cm thick at one speed of 470 cm / min and a cast strand 2.4 cm thick was cast at a speed of approx. 350 cm / min.

The one from the casting machine with a temperature of 360 ° C emerging cast strands were each rolled as follows and the following values for the technological properties determined:

Roll stand I. II III IV V Degree of rolling (%) 50 50 50 50 50 Temperature ( ⁰ C) before 270 220 after 220 160 110 properties // ⁺⁾ L * ' Stretch limit 140 140 N / mm ² tensile strenght 250 300 N / mm ² Elongation at break 80 70 % Fatigue strength 70 70 N / mm ² for 1 % Elongation / year Fold 180 ° D = O very good very good

+) // = parallel to the rolling direction
+) / = perpendicular to the rolling direction

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From the strips rolled to a final dimension of 0.8 cm
the deformation limit curve was determined in each case.
The position of the forming limit curves B shown in the diagram as the mean value of these forming limit curves shows a significant shift in the range of improved degrees of cold forming compared to the forming limit curve A for the strip produced according to the prior art.

For the purpose of comparison, the forming limit curve C for the so-called deep-drawing steel is also shown in
drawn in the diagram.

It can therefore be seen that the zinc-copper-titanium rolled alloy treated by the process according to the invention
the composition has 1.5 to 5.5% copper, 0.25 to 0.05% titanium, optionally 0.005 to 0.05% aluminum, the remainder fine zinc, has considerable creep strength, fracture-free foldability and considerably improved cold formability. These good properties exist not only at room temperature, but are also retained almost completely ^{at temperatures of up to 300 ° C.}

- 5 claims

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L e r s e i t e

Claims (3)

PATENT CLAIMS 1. Process for the production of long-lasting, fracture-free foldable by 180 ° and cold-formable from a zinc wrought alloy with contents of copper from 1.5 to 5.5% by weight and titanium from 0.05 to 0.25% by weight and optionally of aluminum from 0.005 to 0.05% by weight, the remainder being zinc. standing sheets and strips in one operation by continuous casting and rolling, by using a belt casting machine with a rotating mold 0.6 to 2. M- cm thick evenly solidified cast strip produced and then in at least three, preferably five, passes, each with a cross-section reduction of up to 80%, are finish-rolled when hot is according to patent (patent application P 25 10 985.7), characterized in that the melt volume solidifying per unit of time with a value of 250 to less than 3
900 cm per 1 cm of cast strip width is constant. 2. The method according to claim 1, characterized in that the volume of melt solidifying per unit of time is constant with a value of 250 to 850 cm, in particular 600 to 850 cm, per 1 cm of cast strip width. 809839/0360