JPH046251A - Production of aluminum or aluminum alloy strip having uniform distribution of metallic structure - Google Patents

Abstract

PURPOSE:To produce an Al alloy strip having uniform distribution of metallic structure by specifying the hot roughing initiating temp. of an Al alloy ingot with a specific composition, reheating in the course of rolling, and hot finish rolling finishing temp., respectively. CONSTITUTION:At the time of subjecting an ingot of an aluminum alloy having a composition consisting of, by weight, <=1.5% (Si+Fe), one or more components among <=0.5% Cu, <=0.5% Mn, and <=1.0% Mg, and the balance essentially Al to hot rolling (hot roughing + hot finish rolling), this ingot is heated to 350-450 deg.C and hot roughing is started. Then, midway between hot roughing and hot finish rolling in the course of rolling, reheating is exerted up to 300-450 deg.C at 5 deg.C/sec -500 deg.C/sec temp.-rise rate and finish rolling is carried out by performing cooling by means of water soluble rolling mill lubricating oil so that hot finish rolling finishing temp. is regulated to <=250 deg.C, followed by coiling. By this method, the aluminum alloy strip having superior plastic anisotropy and reduced in dispersion of mechanical properties can be obtained.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is an aluminum or aluminum alloy strip having a uniform metallographic distribution suitable for deep drawing of objects, building materials, etc. and for surface treatment such as alumite. This relates to a manufacturing method.

[Prior Art] Conventional hot rolling of continuous aluminum ingots consists of hot rough rolling carried out with 9 to 29 rolling passes, and then hot finishing rolling carried out continuously. After hot finish rolling, it is wound into a coil.

The rough rolling start temperature is 450 to 500°C, and the finish rolling end temperature is around 300°C. Since the recrystallization temperature of aluminum alloy is 250 to 400°C, the degree of progress of recrystallization that occurs repeatedly during hot rolling is due to plastic anisotropy caused by the mechanical properties and crystal structure of the rolled strip. Affects sexuality. Furthermore, chemical solubility, alumite properties, etc. change depending on the precipitation state of alloy components that change at the same time. Furthermore, when hot rolling an ingot, the degree of progress of recrystallization within the strip becomes uneven due to temperature unevenness in the longitudinal direction and the width direction.

In order to solve this problem, a method has been proposed to delay the progress of recrystallization by forced cooling using a water shower or the like during rolling (Japanese Patent Publication No. 56-502), and although no specific method has been specified, cooling A method of adjusting the rolling end temperature by controlling
is proposed.

[Problems to be Solved by the Invention] In the above-mentioned conventionally proposed inventions, the hot rough rolling start temperature is high and the method involves cooling in the middle of rolling to lower the rolling temperature. The recrystallized grains that are formed tend to become coarse. In order to solve this problem, a method of lowering the hot rough rolling start temperature has been proposed (Japanese Patent Laid-Open No. 179488/1988). However, it is inevitable that the finishing temperature of hot finish rolling becomes low, which may cause poor lubrication or corrosion due to the water-borne rolling oil.

[Means to solve the problem] The present invention consists of the following three inventions.

(1) SiFe: 1.5% or less, Cu: 0
．． 5% or less, Mn: 0.5% or less, Mg: 1.0% or less, and the remainder is substantially Al. After heating to 350-450°C, hot rough rolling is started, and the rolling temperature is 300-450°C between rough rolling and finishing rolling.
Reheat to 50°C at a temperature increase rate of 5°C/sec to 500°C/sec, cool with water-borne rolling oil so that the finishing temperature of hot finish rolling is 250°C or less, finish roll it, and wind it into a uniform shape. Method for producing aluminum or aluminum alloy strip having metallographic distribution, (2) Si + Fe: 1.5% or less, Cu
: 0.5% or less, Mn: 0.5% or less, and Mg: 1.0
% or less of each component, and the remainder is substantially Al.
When hot rolling an ingot of aluminum or aluminum alloy, hot rough rolling is started after heating to 350 to 450°C, and the rolling time is 300°C between rough rolling and finishing rolling.
A uniform metal that is reheated to ~450°C at a temperature increase rate of 5°C/sec to 500°C/sec, and after finish rolling, the material temperature is cooled to 250°C or less by forced cooling means immediately before winding the strip. Method for manufacturing aluminum or aluminum alloy strip having texture distribution, (3) S i + Fe: 1.5% or less, C
u: 0.5% or less, Mn: 0.5% or less, and Mg: 1.
Contains 0% or less of one or more of each component, the remainder being substantially A
1. When hot rolling an ingot of aluminum or aluminum alloy, hot rough rolling is started after heating to 350 to 450°C, and after finish rolling, rolling is performed at 5°C/sec to 500°C.
Reheat to 300-450°C at a temperature increase rate of °C/sec,
A method for manufacturing an aluminum or aluminum alloy substrate having a uniform metal structure distribution, which comprises cooling the material temperature to 250° C. or lower using forced cooling means and then winding the material.

In the present invention, the reason why hot rough rolling is started at 350 to 450°C is that rolling from a slab is difficult at temperatures below 350°C, and when the temperature exceeds 450°C, formation of Recrystallized grains tend to become coarser, and flow marks tend to occur during molding.

The reheating temperature is preferably 300 to 450°C. The purpose of reheating is to recrystallize the material finely and uniformly. The temperature is related to heating rate and holding time.

Although the holding time is not particularly determined, it is better to keep it as short as possible in relation to the production line. It is 10 seconds at most.

The reheating rate is preferably 5°C/sec to 500°C/sec.

If it is slower than 5°C/sec, crystal grains tend to become coarser, and
Productivity is poor. When the speed is faster than 500° C./sec, it is difficult to obtain a uniform structure.

The reason for setting the finishing temperature of hot finish rolling to 250°C or less is 2.
This is because when the temperature is 50° C. or lower, no structural difference occurs due to a difference in cooling rate.

Si+Fe 1.5% or less, Cu 0.5% or less, Mn
The reason why Mg is limited to 0.5% or less and Mg to 1.0% or less is to take into consideration the drawability for use in utensils, and if the amounts of these components are exceeded, the drawability will be poor.

[Function] In order to prevent coarsening of recrystallized grains in the initial stage of hot rough rolling, the hot rough rolling start temperature is set as low as possible, and the hot finish rolling end temperature is set high enough to prevent poor lubrication and corrosion. In addition, by making the progress of recrystallization uniform within the strip, a strip with good plastic anisotropy and small variations in mechanical properties can be obtained. At the same time, the precipitation state of the alloy components can be made uniform, and the chemical properties can be made uniform.

[Example] The present invention will be explained in detail below.

During the implementation, a small rolling mill at the research institute was used to confirm the effects of the present invention. The method is as follows.

An aluminum alloy ingot of N011 to 5 having the components shown in Table 1 was semi-continuously cast to 2501io+tX500■
It was cast into an ingot of W x 500m1.

N011 alloy is equivalent to 1100, N002 alloy is No. 1 alloy with 1% Fe, No. 3 alloy is No. 1 alloy with 0.4% Cu, No. 4 alloy is No. 1 alloy with 0.4% Cu. No. 1 alloy with 0.1% Mn, No.
Alloy No. 5 is the N011 alloy with Mg content of 0.85%.

The obtained ingot was homogenized by 25 m52 on each side so as to have a thickness of 200 IIIt, and then heated to 400° C. and hot rolling was started. Hot finish rolling end temperature 3
00° C., and the plate thickness after hot finish rolling was 2■■. After hot finish rolling, it was reheated in a high-frequency induction heating furnace under the conditions shown in Table 2 to recrystallize it, cooled to 250° C. or lower by passing through a mist and water bath, and then extracted.

These steps of hot rolling (from rough hot rolling to winding) were performed continuously.

Aluminum alloy strip coils of alloy Nos. 31 to 5 produced in this way and alloys Nos. 1 to 5 prepared by the conventional method.
Regarding the aluminum alloy strip coil of 5, 1.5■'
Cold rolled to The strength of these cold-rolled sheets in the longitudinal and width directions of the coil, the selvage ratio, and the color tone after alumite were investigated.

Furthermore, deep drawing workability (rough skin, flow marks, etc.) was also investigated. The results are shown in Table 2.

All of the materials No. 1 to 5 according to the invention examples have no variation in strength, selvage rate, and alumite color tone, and have good drawing properties.
No problem. However, in the case of a comparative example in which heating is not performed, although the drawability is good, there are variations in strength, selvage ratio, and alumite color tone.

(vt%) It is possible to obtain an aluminum or aluminum alloy strip suitable as a drawing material or a surface treatment material such as a building panel, and its industrial value is extremely high.

Claims (3)

[Claims] (1) Contains one or more of the following components: Si+Fe: 1.5% or less, Cu: 0.5% or less, Mn: 0.5% or less, and Mg: 1.0% or less, and the remainder is substantially Al. When hot rolling (hot rough rolling + hot finish rolling) an ingot of aluminum or aluminum alloy, hot rough rolling is started after heating to 350 to 450°C, and hot rough rolling is carried out during rolling. 5℃/sec to 5 at 300 to 450℃ between rolling and hot finish rolling
Uniform metal structure distribution characterized by reheating at a temperature increase rate of 00°C/sec, cooling with water-borne rolling oil so that the hot finish rolling end temperature is 250°C or less, finish rolling, and winding. A method for producing an aluminum or aluminum alloy strip having the following. (2) Contains one or more of the following components: Si+Fe: 1.5% or less, Cu: 0.5% or less, Mn: 0.5% or less, and Mg: 1.0% or less, and the remainder is substantially Al. When hot rolling (hot rolling + hot finish rolling) an aluminum or aluminum alloy ingot, hot rough rolling is started after heating to 350 to 450°C, and hot rough rolling is carried out during rolling. and hot finish rolling at 300~450℃ at 5℃/sec~50
After reheating at a temperature increase rate of 0°C/sec and finish rolling,
Immediately before winding the strip, the material temperature is reduced to 2 by forced cooling means.
A method for producing an aluminum or aluminum alloy strip having a uniform metallographic distribution, the method comprising cooling to 50°C or less. (3) Contains one or more of the following components: Si+Fe: 1.5% or less, Cu: 0.5% or less, Mn: 0.5% or less, and Mg: 1.0% or less, and the remainder is substantially Al. When hot rolling (hot rough rolling + hot finish rolling) an aluminum or aluminum alloy ingot, hot rough rolling is started after heating to 350 to 450°C, and after finish rolling, 5 ℃/s
300 to 450℃ at a heating rate of ec to 500℃/sec
1. A method for producing an aluminum or aluminum alloy strip having a uniform metallographic distribution, which comprises reheating the material to a temperature of 250° C. or lower using forced cooling means and then winding the material.