DE19938995A1 - Aluminum alloy board for building materials, electrical machinery components etc - Google Patents

Abstract

The bearing distribution density of each of PP bearing, goss bearing and brass bearing is 3 or less.

Description

The present invention relates to an Al-Mg-Si aluminum alloy sheet or -plate or sheet (hereinafter referred to as "Al-Mg-Si sheet") with good press- or print-formability or -formability and especially with good ones Surface properties. In particular, the following invention relates to an aluminum Mg-Si sheet for forming or shaping, which for example use as a building material for roofs, interior fittings, curtain walls and the like and as material for devices or tools, electrical parts, optical instruments, vehicles such as automobiles, rail vehicles and Aircraft, general mechanical parts and the like is desirable.

In the prior art, Al-Mg alloys were mainly used as aluminum alloy sheets with good formability used. Such Al-Mg alloys have disadvantages, however, that baking hardenability is low and that Traces of tensile stress can be generated when they are press-molded be subjected. Therefore, an Al-Mg-Si alloy has been substituted for the Al-Mg Alloy attracted attention. The Al-Mg-Si alloy exhibits as advantages that they have good cold formability and high corrosion resistance and through aging or remuneration treatment gets a high strength.

However, as in Japanese Patent Provisional Publication No. Hei 7-228956 and Hei 8-232052, there is a problem in that Forming an Al-Mg-Si alloy sheet has a surface roughness on the Sheet surface is generated, which "groove track" (English: "ridging marks") to be named. The groove marks are strip-like irregularities, which are generated parallel to the direction of rolling when the sheet is the Forms is subjected. You will be particularly noticeable then  generated when molding methods such as stretch forming, drop forging, Deep drawing or bulging or bulging, in the direction perpendicular to the direction of rolling can be applied to the sheet. A sheet with groove marks can not used for products due to its poor appearance which in particular need a fine surface, such as interior fittings parts, camera housings, outer panels for motor vehicles and the like.

Japanese Patent Provisional Publication No. Hei 7-228956 and No. Hei 8-232052 intended to produce grooves prevent traces by setting the conditions in every process like that Conditions of hot rolling, strictly control to thereby avoid grains generate which are fine and have a random crystal orientation.

However, these prior art documents could not Find out the composition of a sheet in which there are no groove marks generated, and could meet the newer, stringent quality requirements of a surface does not meet sufficiently.

The Al-Mg-Si aluminum alloy described in the Japanese preliminary patent Publication No. Hei 8-325663 was described with one on the Stretchability focused attention developed while the surfaces properties were not considered. Therefore, the positioning of the newer, do not meet strict conditions for surface quality.

The present invention is therefore based on the object of an Al-Mg-Si To provide aluminum alloy sheet for forming or reshaping which the generation of groove tracks should be prevented and its Surface should be high quality.

This task is characterized by that in the claims Objects solved.

In the context of the present invention, it was found that it was Verhin  effective generation of groove tracks in an Al-Mg-Si alloy sheet is to perform a texture check precisely, thereby the textures of the Goss orientation, PP orientation and brass orientation in the end product too to reduce.

In particular, an Al-Mg-Si alloy sheet according to the invention has good Surface properties as a material for shaping or shaping textures in which the orientation distribution density of the Goss orientation 3 or is less, the orientation distribution density of the PP orientation 3 or is less and the orientation distribution density of the brass orientation is 3 or is less.

As long as an Al-Mg-Si alloy on the textures described above points, the generation of groove tracks is suppressed. One especially before Al-Mg-Si alloy according to the present invention contains 0.2 to 1.5% Mg and 0.2 to 1.5% Si. The Al-Mg-Si type alloy may be one or several elements selected from the group consisting of Mn, Cr, Fe, Zr, V and Ti are selected in a total amount of 0.01 to 1.5 wt .-% and below included the condition that Mn in an amount of 1.0% by weight or less, Cr in an amount of 0.3% by weight or less, Fe in an amount of 1.0% by weight or less, Zr in an amount of 0.3% by weight or less, V in in an amount of 0.3% by weight or less and Ti in an amount of 0.1% by weight or less. The Al-Mg-Si type alloy may also be one or several elements selected from the group consisting of Cu, Ag, Zn and Sn, are selected in a total amount of 0.01 to 1.5 wt .-% and below that Included condition that Cu in an amount of 1.0 wt% or less, Ag in an amount of 0.2% by weight or less, Zn in an amount of 1.0% by weight % or less and Sn in an amount of 0.2% by weight or less.

The present invention can be an Al-Mg-Si type alloy sheet as Provide molding material where the creation of groove marks is suppressed.  

After several investigations into the cause of the groove marks, which, when subjected to a conventional aluminum alloy, Forms are created, it has been found that the creation of groove marks insufficient texture control.

Textures of an aluminum alloy are described below. In an aluminum alloy, there are orientation components of the cubic orientation, the RW orientation, the CR orientation, the brass orientation, the Goss orientation, the PP orientation, the C orientation, and the S orientation, which are the following :
Cubic orientation {001} <100 <
RW orientation {001} <110 <
CR orientation {001} <520 <
Brass orientation {011} <211 <
Goss orientation {011} <100 <
PP orientation {011} <122 <
C orientation {112} <111 <
S-orientation {123} <634 <.

According to the present invention, a deviation in orientation component of one of the above exact orientation by ± 10 degrees or less essentially than belonging to this orientation component considered. Only with regard to the brass orientation and the PP orientation component becomes a deviation of the orientation component from the exact brass or PP orientation of ± 8 degrees or less than for brass or PP orientation component considered accordingly.

A common aluminum alloy is from the above orientations components built. If the composition ratio changes, the plastic anisotropy (as described below) changes one Sheet metal and the press formability becomes better or worse.  

A quantitative assessment of the orientations describes the orientation ver pitch density. The orientation distribution density is determined by the ratio of the Size of an orientation represents the size of a random orientation and is measured by measuring at least three conventional pole figures with a ge ordinary X-ray diffraction method and use of the crystallite orientation distribution function [see Shin-ichi Nagashima, "texture" (ver published by Maruzen Kabushiki Kaisha) 1984, pages 8 to 44; Seminar of the Metallurgical Society "Texture" (published by the Metallurgical Society of Japan) 1981, pages 3 to 7]. Alternatively, the Orientie distribution distribution density can also be obtained from data which are determined by a Electron radiation scattering method, an SEM (Scanning-Electron-Microsco py) -ECP (Electron-Channeling-Pattern) method, a SEM-EBSP (Electron-Back- Scattered Pattern) method or the like while measuring a crystallitorium distribution function. Since the orientation distribution coincides with the Changes the direction of the thickness of a sheet, the average of the Orientie distribution densities at some arbitrarily selected points in the direction the thickness calculated.

The mechanism of creating groove tracks was investigated by the textures of Al-Mg-Si alloy sheets were varied and it was examined whether groove marks were created in these sheets and it was found that the Goss orientation, the PP orientation and the Brass orien which show strong plastic anisotropy in the same plane, Cause groove marks.

In particular, the Goss orientation, the PP orientation and the brass Orientation of the R value (Lankford value) in the same plane is a plastic one Anisotropy, which is much larger than in other orientations. Still special He becomes familiar with the Goss orientation, the PP orientation and the brass orientation a reduction or reduction in the thickness of a sheet by pulling the Sheet in the direction of the width of the sheet, in the direction at an angle of 20 ° to the direction of rolling or towards an angle of 55 ° to the direction tion of the rolling hardly caused while reducing the thickness by  Pulling the sheet in the other directions is caused. This big one Difference in the thickness reduction rate causes irregularities a surface (groove marks).

Therefore, it is effective in suppressing the generation of groove marks Textures of the Goss orientation, the PP orientation and the brass orientation to diminish. Especially if the orientation distribution density of the Goss Orientation is 3 or less, the orientation distribution density of the PP Orientation is 3 or less and the orientation distribution density of the brass Orientation is 3 or less, the generation of groove tracks is underneath presses. If, on the other hand, the orientation distribution density of one of these orias tations exceeds the above, groove marks are visibly generated and the quality of a surface deteriorates. It is preferred that the Orientation distribution density of the Goss orientation is 2 or lower, that Orientation distribution density of the PP orientation is 2 or less and the Orientation distribution density of the brass orientation is 2 or less.

The alloy elements or components of the Al-Mg-Si Alloy are described.

Mg, Si

These elements are important because they form Mg ₂ Si aggregates (clusters) called "GP zones" or intermediate phases and contribute to hardening by baking. They also play a role in improving the work hardening property of a sheet and increasing the fracture limit in press molding. Furthermore, stable Mg ₂ Si phases generated during the heating act as preferred sites for the formation of nuclei of the recrystallization orientations and have a great effect on the formation of the textures of a sheet.

If both the Mg content and the Si content are less than 0.2% by weight sufficient strength cannot be obtained by baking. If the Mg content and the Si content both exceed 1.5% by weight, the Property of hardening by baking is poor and the moldability is due to  the formation of bulky connections from which breaks easily occur can, much worse. The formation of desired textures is also prevented. It is better if the Mg content is 0.8% or less and the Si content Is 1.3% or less.

Mn, Cr, Fe, Zr, V, Ti

Mn, Cr, Zr, V and Ti form a large amount of fine dispersoids, if that Soak for a long time of 4 hours or longer at a high Temperature of 530 ° C or higher is carried out. The dispersoids act as preferred sites for the formation of nuclei or cores of recrystallization orientations and are effective for obtaining desired textures. The Disperoids are also effective to make the crystal grains finer and thereby increasing the cracking limit when molding. Furthermore, Mn and Cr important insofar as they contribute to hardening by baking. However, if the Mn content exceeds 1.0% by weight, Cr content exceeds 0.3% by weight, Zr Content exceeds 0.3% by weight, the V content exceeds 0.3% by weight or the Ti Content exceeds 1.0% by weight, coarse-grained compounds are formed, which make the occurrence of fractures likely, so that the malleable becomes much worse. The formation of desired textures is also prevented.

Fe forms constituent phases or intermetallic compounds, such as Al ₇ Cu ₂ Fe, Al ₁₂ (Fe, Mn) ₃ Cu ₁₂ , (Fe, Mn) Al ₆ , α-AlFeSi, β-AlFeSi and the like. These constituent phases act as preferred sites for the formation of crystal nuclei of the recrystallization orientations and are effective in obtaining desired textures. However, if the Fe content exceeds 1.0% by weight, whoever forms the coarse-grained compounds from which breaks easily occur, so that the moldability becomes much poorer. The formation of desired textures is also prevented.

If the total content of the above elements is less than 0.01 wt. %, the effects described above are not obtained. If the Content of the above elements exceeds 1.5% by weight in total coarse-grained connections from which breaks can easily occur,  formed so that the formability is much worse. The formation of desired Textures are also prevented.

A particularly preferred range of the amount of each element is as follows: the Mn content is 0.5% by weight or less, Cr content is 0.2% by weight or less, the Fe content is 0.5% by weight or less, the Zr content is 0.2% by weight or less, the V content is 0.2% by weight or less and the Ti content is 0.05% by weight or less.

Cu, Ag, Zn, Sn

These elements promote the formation of Mg ₂ Si aggregates (clusters), which are called "GP zones", or intermediate phases. Cu, Ag and Zn accelerate hardening by baking. Sn delays room temperature aging in stages before baking and promotes aging when baking. However, if the total content of the above elements is less than 0.01% by weight, the effects described above are not obtained. On the other hand, if the copper content exceeds 1.0% by weight, the Ag content exceeds 0.2% by weight, the Zn content exceeds 1.0% by weight, the Sn content exceeds 0.2% by weight. % exceeds or the sum of the contents of these elements exceeds 1.5%, coarse-grained compounds are formed, from which breaks easily occur, so that the formability becomes worse. The formation of desired textures is also prevented.

A particularly preferred range of the amount of each element is as follows: Cu Content is 0.5% by weight or less, Ag content is 0.1% by weight or less, Zn content is 0.5% by weight or less, and Sn content is 0.1% by weight or less fewer.

Preferred manufacturing conditions will next be described.

After ordinary pouring, warming up or even heating up carried out. When transition metals such as Mn, Cr, Fe, Zr, V and the like were added and soaked for a long time of 4 hours  or longer at a high temperature of 530 ° C or higher a large number of fine dispersoids can be excreted or deposited be beaten. These dispersoids are used to obtain desired textures effective and make the grains finer. Then hot rolling is performed and then cold rolling is carried out. If the start temperature of the Hot rolling is higher than 450 ° C, the roll or roll temperature. "coiling temperature") of hot rolling is higher than 360 ° C and the final Reduction rate of cold rolling is 25% or less can be desired Textures are preserved. Annealing or tempering can be done after the hot whale zen be carried out.

The fact is of particular importance for obtaining the desired textures that the development of an α fiber [see Kunio Ito; "Light metal", volume 43 (1993), No. 5, pages 285 to 293] in an alloy before the heat of solution action, to which group orientations whose <110 <axis is normal to Roll plane is, like a Goss orientation and a Brass orientation, the development of Goss orientation, PP orientation and the like solution annealing or solution treatment during precipitation hardening caused. Therefore, the development of an α fiber must be done in stages before the solution glow are suppressed. An α fiber develops during the hot whale zens. In cold rolling, the higher the reduction rate, the more so the α fiber develops. Therefore, to prevent the development of the α fiber , it is necessary to increase the rolling temperature of the hot rolling in order To cause recrystallization and thereby the development of an α fiber suppress during hot rolling, or the rate of reduction of Cold rolling to decrease the development of an α fiber during the Suppress salt rolling. In particular, it is desirable that the Roll temperature of hot rolling is 360 ° C or higher and the end-reduce Oration rate or rate of cold rolling is 85% or less. Furthermore, if that Hot rolling is started at a temperature higher than 450 ° C, which occurs Recrystallization during rolling slightly so that orientations which do not belong in the α fiber, are formed and develop an α fiber is reduced. With such suppression of the development of an α fiber  in an alloy before solution annealing, the development of Goss, Brass and PP orientations in the alloy after solution annealing are suppressed. This helps suppress the generation of groove marks.

Note that the production of an α fiber by hot rolling due to performing annealing or tempering after hot rolling zen to effect recrystallization can be reduced.

Solution annealing is carried out last. It is desirable that the high Temperature of 530 ° C is maintained during solution annealing.

example 1

Alloys of three different compositions, i.e. H. Al-0.6% Mg-1.0% Si Alloy (hereinafter referred to as "base alloy"), Al-0.6% Mg-1.0% Si 0.1% Mn alloy (hereinafter "alloy with Mn addition") and Al- 0.6% Mg-1.0% Si-0.1% Fe alloy (hereinafter referred to as "alloy with Fe addition" were poured in a conventional manner and soaked in subjected to a temperature of 550 ° C for 8 hours. Then the Alloys subjected to hot rolling (started at a temperature of 500 ° C) and thereby from sheets of a thickness of 500 mm in sheets of a thickness shaped from 10 to 1.5 mm. The rolling temperature of the hot rolling was varied iert. Annealing after hot rolling (according to the present invention as "Raw annealing") was carried out for some sheets and for others Sheets not carried out. Furthermore, the reduction in cold rolling varies. The sheets were cold rolled into sheets 1 mm thick molded and then solution annealing at a temperature of 550 ° C for 1 minute subject.

A tensile strain of 15% was applied to the sheets and the top Surfaces of the sheets were then coated and examined to see if there were any groove marks generated or not (groove marks become more visible through coating made, d. H. Coating makes it easy to find groove marks). Further was the critical height for cracking or tearing as an index for the formability  by performing a stretch forming test in a flat area tensile stress or a tensile stress measured in the plane.

Measurements of the textures were made in three different after solution annealing Leveled each sheet, d. H. a surface plane, a 1/4 thickness plane and a center-in-the-thickness plane or a central thickness plane. In particular, conventional pole figures of (100), (110) and (111) were made by a common X-ray scattering method using Copper as the target and the condition that the X-ray tube voltage is 50 kV was and the X-ray tube current was 200 mA. Subsequently was calculated using the crystal orientation distribution function Orientation distribution density of each orientation on each of the above three Levels calculated. Then were used as orientation distribution densities throughout Blech the average orientation distribution densities on the three levels of one Blechs calculated.

The results are shown in Table 1. It is clear that the generation of Groove marks in the materials of the invention is suppressed and that this Materials have good formability.  

Example 2

Various alloys, as shown in Table 2, which added Ele elements such as Mg, Si, Mn, Cr, Fe, Zr, V, Ti and the like were included poured in a conventional manner and soaking in one Subject to temperature of 550 ° C for 8 hours. Then there was hot rolling carried out (starting temperature: 500 ° C), thereby the alloys in sheets to form a thickness of 10 to 1.5 mm. The roll temperature of the hot whale zens was varied. Raw annealing was not carried out. The sheets were formed into 1 mm thick sheets by cold rolling and then one Solution annealing at a temperature of 550 ° C for 1 minute.

Table 2

Added elements or alloy components (%)

With regard to the sheets obtained, it was investigated whether groove marks were produced were or not. The critical height up to the crack formation was determined by one Stretch forming test was measured and the textures were measured as in Example 1 sen.

The results are shown in Table 3. It is clear that the generation of Groove marks in the materials of the invention is suppressed and that such materials have good formability.  

Table 3

Conditions for the production of alloys, textures, groove marks, the critical height for crack formation during molding

Example 3

Various added elements as shown in Table 4, such as Mg, Si, Mn,  Cr, Fe, Zr, V, Ti, Cu, Ag, Zn, Sn and the like have been conventional Poured way and soaking at a temperature of 550 ° C for 8 Subjected to hours. Then hot rolling was carried out (starting temperature: 500 ° C), thereby to form the alloys in sheets with a thickness of 10 to 1.5 mm to reshape. The rolling temperature of the hot rolling was varied. Raw annealing was not accomplished. The sheets were made into sheets 1 mm thick formed by cold rolling and then solution annealing at one temperature of 550 ° C for 1 minute.

Table 4

Added elements or alloy components (%)

It was investigated in the sheets obtained whether groove marks were produced or not, the critical height up to the cracking was determined by a stretching mung test measured and the textures were measured as in Example 1.  

The results are shown in Table 5. It is clear that the generation of Groove marks in the materials of the invention is suppressed and that this Materials have good formability.

Table 5

Conditions for the production of alloys, textures, groove marks, the critical height for crack formation during molding

Claims (5)

1. Al-Mg-Si aluminum alloy sheet for molding, which textures in which the orientation distribution density of the Goss-Orientie is 3 or less, the orientation distribution density of the PP orien is 3 or less and the orientation distribution density of the Brass orientation is 3 or less. 2. Al-Mg-Si aluminum alloy sheet according to claim 1, wherein the Al-Mg- Si aluminum alloy sheet as alloy components 0.2 to 1.5% by weight % Mg and 0.2 to 1.5 wt .-% Si contains. 3. Al-Mg-Si aluminum alloy sheet according to claim 1 or 2, wherein Al-Mg-Si aluminum alloy sheet also as alloy components contains a total of 0.01 to 1.5% by weight of one or more elements, which from the group consisting of 1.0 wt .-% or less Mn, 0.3 % By weight or less Cr, 1.0% by weight or less Fe, 0.3% by weight or less Zr, 0.3 wt% or less V and 0.1 wt% or less Ti are selected. 4. Al-Mg-Si aluminum alloy sheet according to one of claims 1 to 3, the Al-Mg-Si aluminum alloy sheet as alloy components in a total amount of 0.01 to 1.5% by weight of the total weight furthermore contains one or more elements which are selected from a group, consisting of 1.0 wt% or less of Cu, 0.2 wt% or less Ag, 1.0 or less of Zn and 0.2 wt% or less of Sn are. 5. Al-Mg-Si aluminum alloy sheet for molding according to one of the An  Proverbs 1 to 4, the orientation distribution density of the Goss-Orien is 2 or less, the orientation distribution density of the PP Orientation is 2 or less and the orientation distribution density is Brass orientation is 2 or less.