JPS60243255A - Manufacture of al-cu-mg alloy material - Google Patents

Abstract

PURPOSE:To manufacture an Al-Cu-Mg alloy soft material superior in formability by working plastically an Al-Cu-Mg alloy ingot to a material of a prescribed size, heating rapidly said material under a specified condition to soften it then cooling. CONSTITUTION:The ingot contg. by weight, about 1.0-6.0% Cu, about 0.1-2.0% Mg, if necessary 1 or >=2 kinds among about 0.01-1.2% Mn, about 0.01-1.2% Si, about 0.05-0.3% Cr, about 0.005-0.15% TiO, about 0.005-0.20% Zr and the balance Al with inevitable impurities is worked plastically according to usual method. Next, said worked material is heated rapidly to 325-430 deg.C temp. by rising rate faster than the average 11 deg.C/min and softened, then cooled by average <=30 deg.C/hr rate. If necessary, furthermore, heated to 250-430 deg.C, held for <=24hr, and cooled by average <=30 deg.C/hr cooling rate.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a wrought aluminum alloy material, and more specifically, A1. The present invention relates to a method for manufacturing a Cu-Mg alloy soft material.

(Prior Art) In general, high-strength aluminum alloys have poor formability, so they are processed in a soft state, and then subjected to solution treatment and quenching. Al-Cu-Mg alloys that are the subject of the present invention, such as JTS^202'l, 2017, 2014
This is no exception.

Conventionally, this soft material has been manufactured by annealing in a batch furnace, but in this case the heating rate is slow (50°C
/Hr), the crystal grains of the soft material become coarse and formability deteriorates. Furthermore, even when rough processing is performed after quenching to correct distortion caused by quenching, if the crystal grains are large, surface roughness and minute cracks will occur. In particular, in areas of soft materials that have been subjected to low processing at a processing rate of 10 to 30%, the recrystallized grain structure becomes extremely coarse during the subsequent solution treatment and quenching process, and roughness and microcracks occur during strain correction, resulting in the appearance of the product. This is a big problem in terms of quality.

(Problems to be Solved by the Invention) 1 - The present invention aims to improve the formability of soft materials of Al-Cu-Mg alloys and the coarsening of crystal grains during solution treatment, etc. in the production of soft materials. This is an attempt to resolve the issue from a legal standpoint.

In other words, the crystal grains are fine in the soft material state, and the formability expressed by elongation and Erichsen values is good, and furthermore, no matter what rate of cold working is applied in this state, it will not be regenerated by subsequent solution treatment. Crystal grains do not become coarse ^1-C
The present invention provides a method for manufacturing a u-Mg alloy material.

Structure of the Invention (Means for Solving the Problems) A manufacturing method of A1-Cu-Mg based alloy soft material in the present invention i, using a so-called continuous annealing furnace instead of a batch furnace for refining to make it soft. With this in mind, 1.6
The material was plastically worked into a predetermined size and shape according to a conventional method, and then heated to a temperature of 325 to 430°C with an average of ti"c/sin (
Excellent formability, characterized by rapid heating and softening at a temperature increase rate faster than 30°C/Hr (hours, same below), followed by cooling at an average cooling rate of less than 30°C/Hr (hours, same below). A method for producing an Al-Cu-axial alloy soft material.

2. The ingot was plastically worked to a predetermined size according to a conventional method, and the material was rapidly heated to a temperature of 325 to 430°C at a heating rate faster than an average of 11°C/min to soften it, and then heated to an average of 30°C/min. Cool at a cooling rate of 250 Hr or more, and
Heated to ~430℃ and held within 24 hours, average 30℃/H
A method for producing an Al-Cu-Mg alloy soft material with excellent formability, characterized by cooling at a cooling rate of less than r.

It is.

(Function) The structure of the present invention will be explained in detail below along with its function.

The target alloy has θ phase (CuA j2
), an Al-Cu-Mg alloy containing an S phase (CuMgAl2).

The above-mentioned JIS^2024, 2017, 201i, etc. are included, but are not limited to these.

If the composition range is specifically shown, it is an essential component.

Cu1. '0 to 6.0% (weight%, same below), M
g (1.1-2.0%, further MnO, Q as necessary)
l~L, 2%, Si0, 01~1.2%, CrO,
005~0.3%, TiO, 005~0.15%,
It is an alloy containing one or more of ZrO, 0.005% to 0.20%, and the remainder consisting of unavoidable impurities and A1.

The reason for adding these alloy components will be explained.

Cu: Cu is an element that gives strength, and the content is.

Less than 1.0% is T4. The strength after T6 treatment decreases, and if the content exceeds 6.0%, crystallized substances increase and T4.
Toughness and elongation decrease after T6 treatment. Therefore, the Cu content is set to 1.0 to 6.0%.

Mg: Mg is an element that imparts strength, and the content is
T4. below 0.1%. The strength after T6 treatment decreases, and if the content exceeds 2.0%, T4. Toughness and elongation decrease after T6 treatment. Therefore, the Mg content is 0.1 to 2.
Set to 0%.

The following are the components to be included as necessary.

Mn: Mn is an element that stabilizes the structure and is also an element that impairs strength. If the content is less than 0.013, this effect is absent, and if the content exceeds 1 or 2%, the effect is saturated and giant crystallized substances are produced. Therefore, the Kn content is set to 0.01 to 1.2%.

Si: Si is an element that impairs strength, and if the content is less than 0.01%, this effect is absent, and if the content exceeds 1.2%, the toughness after T4/T6 treatment will decrease. .

Therefore, the Si content is set to 0.01 to 1.2%.

However, when such strength is not required or when the strength level can be maintained by containing other elements, the inclusion of Si is not essential, and in this case it is treated as an unavoidable impurity.

Cr: Cr is an element that stabilizes the structure and provides strength. If the content is less than 0.00%, this effect will not be achieved, and if the content exceeds 0.3%, giant crystallized substances will be produced. Therefore, the Cr content is 0.005
~0.3%.

Ti: Ti is an element that refines the ingot structure, and if the content is less than o, oos%, this effect will not occur, and if the content is less than 0.15
If the content exceeds %, giant crystallized substances will be produced. Therefore, T
The i content is 0.005 to 0.15%.

Zr: Zr is an element that refines the structure of the ingot and stabilizes it. If the content is less than 0.005%, this effect is absent, and if the content exceeds 0.20%, giant crystallized substances are formed. . Therefore, the Zr content is 0.005-0.20%
shall be.

Note that Fe and Si as non-habitatable impurities are allowed up to 0.5%.

Next, the alloy ingot having the above composition is plastically worked to a predetermined size according to a conventional method.

In other words, the ingot is hot-worked and then further cold-worked to achieve the specified dimensions. I often do this. This soaking treatment is
”+ Solid solution of Mge Sl and Kn, Cr, Zr,
The purpose is to precipitate Ti, and the ingot casting is 400 to 52
Heat treatment at 0°C for 2-48 hours. If the temperature is less than 40 (Ic), the effect is not sufficient, and if it exceeds 520°C, local melting will occur.In addition, if heating is less than 400°C, hot workability will decrease, and if it exceeds 520°C, local melting will occur. So 4
Heat treatment at 00-520°C.

Moreover, when performing cold working, the effect of the present invention does not change even if intermediate sintering is performed at 350 to 500° C. before or during cold working.

The material that has been plastically worked to a predetermined size in this way is
The material is rapidly heated to a temperature of 430° C. at an average heating rate of 11 T:/in to soften it.

If the heating temperature is lower than 325°C, recrystallization will not be completed during rapid heating and a processed structure will remain, resulting in poor formability. 430℃
At temperatures exceeding 100 gw, the amount of solid solution of 'gw Cuy'Sl increases, and subsequent cooling causes non-uniform precipitation, resulting in poor formability in soft materials and furthermore, in the processed part, the following Crystal grains become coarse during the solution treatment process.

Further, if the temperature increase rate is lower than an average of 11° C./win, the crystal grains become coarse and the moldability of soft materials deteriorates.

Next, in the first invention of the present application, cooling is performed at an average cooling rate of less than 30° C./Hr. If the cooling rate is less than 30°C/llr on average, a completely soft material (0 material) is obtained, so the material has good formability, but if the cooling rate is higher than this, quenching occurs and age hardening occurs. Therefore, the moldability decreases. Note that since age hardening does not actually occur below 250°C, the cooling rate can be controlled up to this temperature.

Because the heating rate must be faster than an average of 11"C/sin for the reasons mentioned above, a continuous annealing furnace is often used.゛It is almost impossible to perform efficient production in a blunt furnace.In this way, the cooling rate is 30℃/)l on average.
If it becomes more than r, the method of the second invention of the present application may be used.

That is, the softener is cooled at an average cooling rate of 30° C./Hr or more, then reheated to 250 to 430° C., held for less than 24 hours, and cooled at an average cooling rate of less than 30° C./Hr.

In this case of reheating, a patch furnace can be used because there is no need to control the temperature increase rate, and therefore the cooling rate can be adjusted to an average of 30°C/30°C.
) Ir.

Even if the cooling rate after the first stage of softening is fast, it is possible to obtain an Al-Cu-Mg alloy soft material with good formability by reheating and slowing down the subsequent cooling rate. can.

Note that it is more preferable for the reheating temperature to be lower than the first stage rapid heating temperature for moldability.

(Example) Three types of alloys A, B, and C shown in Table 1 were semi-continuously cast, and the ingots were soaked at 490°C for 10 hours and then heated at 460°C for 3 hours. , hot rolled to a plate thickness of 4III11 and heated in a batch furnace at 370°C for 3 hours.
The material was subjected to intermediate annealing of R and cold rolled to a plate material with a thickness of 0.8 m+.

This material is subjected to heat treatment within the scope of the present invention or other heat treatment to make it into a soft material with mechanical properties (tensile strength σB, strength resistance 0.2, elongation δ, Erichsen value, presence or absence of rough skin) was measured. In addition, after cold rolling this soft material by 15%, it is subjected to solution treatment by placing it in a heated furnace.
Immediately after water quenching (503° C. x 40 ain) of the 1n, C alloy, the degree of surface roughness due to 180° bending was observed.

Tables 2, 3, and 4 show these heat treatment conditions, mechanical properties of the soft materials, and bendability after cold working, solution heat treatment, and water quenching.

In the table, the first stage heat treatment refers to the rapid heating and softening and subsequent cooling common to the first and second inventions of the present application, and
The stage heat treatment refers to reheating and cooling after the first stage heat treatment of the second invention of the present application.

(Effects of the Invention) As is clear from Tables 2, 3, and 4, the material manufactured using the manufacturing method of the present invention has improved elongation and Erichsen value of soft materials, and has fine crystal grains that can be molded. Since it does not cause surface roughening and does not cause coarsening of crystal grains even when subjected to low-temperature post-processing solution treatment, it has many advantages such as a good product appearance during distortion correction after quenching.

Claims (1)

[Claims] 1. A material that has been plastically worked into a predetermined size from an ingot according to a conventional method is heated to a temperature of 325 to 430°C at an average rate of 11°C/wIin.
(same meaning below), rapidly heated and softened at a faster heating rate, then averaged 30℃/Hr (meaning time,
A method for producing a ^1-Cu-Mg based alloy soft material with excellent formability, characterized by cooling at a cooling rate of less than (the same applies hereinafter). 2. The ingot was plastically worked to a predetermined size according to a conventional method, and the material was rapidly heated to a temperature of 325 to 430°C at a heating rate faster than an average of 11°C/min to soften it, and then softened by an average of 30°C/min. Cool at a cooling rate of 250 Hr or more, and
Heated to ~430℃ and held within 24 hours, average 30℃/H
A method for producing an Al-, Cu-Mg based alloy soft material with excellent formability, characterized by cooling at a cooling rate of less than r.