RU2255132C1 - Aluminum-base deformable alloy and article made of this alloy - Google Patents

Abstract

FIELD: alloy metallurgy.

SUBSTANCE: invention relates to deformable thermally non-strengthened welding alloys based on the system Al-Mn. The proposed alloy and article made of its comprise the following components, wt.-%: manganese, 0.5-1.7; calcium, 0.002-0.5; sodium, 0.0002-0.01; at least metal taken among the group comprising iron, copper, zirconium and chrome, 0.02-1.0; aluminum, the balance. Invention provides the development of alloy based on the system Al-Mn and article made of this alloy eliciting the enhanced value of creep limit and high relative elongation that provides good deformability in cold state and enhanced workability by cutting.

EFFECT: valuable properties of alloy and article.

3 cl, 2 tbl, 1 ex

Description

The invention relates to the field of metallurgy of alloys, in particular, to deformable thermally unstrengthened weldable alloys based on the Al-Mn system and products made from it, intended for use in aviation, construction, automotive and other industries, for example, for lightly loaded structures (benzo - and oil pipelines, tanks), as well as heat exchangers, decorative finishes, transportation and storage of various chemicals, etc.

On the basis of the Al-Mn system, alloys of the 3000 series were developed, the alloys possess a range of valuable properties: high corrosion resistance, weldability, high ductility, and processability both in hot and cold processing. The alloys of this system do not require hardening, which reduces the complexity of obtaining semi-finished products from them, and there are no metal losses associated with warping. However, the level of strength properties, especially the yield strength of these alloys is low. With the help of cold deformation, it is possible to increase the strength properties, but at the same time ductility is sharply reduced.

Known alloy based on aluminum grade 3003, containing in wt.%:

manganese 1.5

silicon ≤0.6

iron ≤0.7

copper ≤0.2

zinc ≤0.1

aluminum rest

(Alloy Dig., 1988, Jan, publ. In the Review journal "Metallurgy" No. 5, 1988, 5I1097).

The alloy is used in the form of cold-deformed semi-finished products (sheets, plates). The alloy has a low yield strength of 4 kgf / mm ² . To increase the strength properties, cold deformation is used, while the relative elongation is significantly reduced - up to 4%, which leads to a sharp drop in the manufacturability of the semi-finished product from this alloy and the inability to obtain complex shapes from it.

Closest to the proposed technical solution is an alloy based on aluminum grade AMts, which contains in wt.%:

manganese 1.0-1.6

impurities are allowed in the alloy, not more than

iron 0.7

silicon 0.6

copper 0.2

aluminum rest

(M.V. Maltsev Metallography of industrial non-ferrous metals and alloys. M: Metallurgy, 1970, p. 47-48).

A disadvantage of the known alloy is also a reduced strength, especially the yield strength in the annealed condition. The increase in strength by deformation reduces ductility, and, as a result, the ability to formability decreases, it becomes impossible to obtain a product of complex shape.

An object of the invention is to develop an alloy based on the Al-Mp system and an article made of this alloy in order to increase the yield strength at high elongation, which provides good cold deformability and increased machinability by cutting.

To achieve the technical task, a deformable aluminum-based alloy is proposed, containing manganese and additionally calcium, sodium and at least one metal selected from the group comprising iron, copper, zirconium and chromium, with the following ratio of components in wt.%:

manganese 0.5-1.7

calcium 0.002-0.5

sodium 0.0002-0.01

at least one metal

selected from the group including

iron, copper, zirconium and chromium 0.02-1.0

aluminum rest

and an article made from it.

In the alloy, the presence of impurities is not more than in wt.%:

titanium 0.2

zinc 0.5

silicon 0.5

magnesium 0.4

Ca in an amount of 0.002-0.5% together with 0.0002-0.01% Na in an Al-Mn alloy increases the yield strength of the alloy, improves cold deformability and the ability to be cut. When the content of Ca and Na in the alloy is respectively lower than 0.002 and 0.0002%, the effect of exposure is practically not manifested, and when the content is above 0.5 and 0.01%, the plastic properties decrease, especially during cold deformation.

Iron, zirconium, copper and chromium belong to the group of transition metals. To increase the strength properties of the alloy and grain refinement during recrystallization, at least one metal selected from the group consisting of iron, zirconium, copper and chromium is introduced. When the content of iron and / or copper, and / or zirconium, and / or chromium is less than the lower limit, the positive effect is not manifested, when the content is above the upper limit, the ductility of the alloy decreases due to the appearance of primary intermetallic compounds.

The alloy can be made in the form of pressed, rolled and forged and stamped semi-finished products. The preparation of the proposed alloy allows the use of a secondary charge with the involvement of a wide range of waste.

The alloy allows to obtain products of complex shape, for example, tanks, heat exchangers, gas and oil pipelines, etc.

An example illustrating the invention is shown in tables 1 and 2. Table 1 shows the chemical composition of the tested compositions of the proposed and known alloys. In preparing the compositions, aluminum, calcium, sodium, and copper were introduced in pure form, and manganese, iron, zirconium, and chromium were introduced as ligatures. Melting was carried out in an electric furnace. From the cast ingots, a hot-pressed strip and 1.5 mm thick cold-rolled sheets were obtained. Table 2 shows the properties of semi-finished products from the tested compositions of the proposed alloy in comparison with the known.

As can be seen from the data of Table 2, the proposed alloy, in comparison with the known one, is characterized by higher strength properties, especially the yield strength at high relative elongation, which indicates a good ability to handle cold deformation and makes it possible to manufacture products of complex shape using the progressive cold method stamping. The proposed alloy is satisfactorily processed by cutting, welded by all types of welding, insensitive to stress concentrators, therefore, it can be joined by welding, riveting, bolted joints. This allows us to recommend the proposed alloy for implementation in aircraft, construction, automotive and other industries.

Thus, the proposed wrought alloy based on aluminum can be used for the manufacture of various products, for example, for lightly loaded structures (gas and oil pipelines, tanks), heat exchangers, decorative finishes, transportation and storage of various chemicals, etc.

Table 1 The chemical composition of the tested compositions Alloy Alloy number Mn Sa Si Zr Cr Fe Na Al Famous 1 1,2 - - - - - - ost Proposed 2 1,2 0,03 0.02 - - - 0.002 ost 3 1.7 0.002 - 0.05 0.05 0.4 0,0002 ost 4 0.5 0.5 - - - 1,0 0.01 ost Note: The proposed and known alloys contain titanium, magnesium, silicon and zinc at 0.05% each.

table 2 Properties of semi-finished products from the proposed and known alloys Alloy Alloy number 1.5 mm sheet (annealed) Press strip σ _in , MPa σ _0.2 , MPa δ,% σ _in , MPa σ _0.2 , MPa δ,% Famous 1 108 55 thirty 165 106 23 Proposed 2 114 85 33 - - - 3 123 90 28 181 123 twenty 4 118 86 31 - - - Note: When milling a known alloy, sticking (enveloping) of the metal on the tool was observed, while the proposed alloy was processed satisfactorily.

Claims (2)

1. A deformable aluminum-based alloy containing manganese, characterized in that it further comprises calcium, sodium and at least one metal selected from the group comprising iron, copper, zirconium and chromium, in the following ratio, wt.%: Manganese 0.5-1.7 Calcium 0.002-0.5 Sodium 0.0002-0.01 at least one metal selected from the group including Iron, copper, zirconium and chromium 0.02-1.0 Aluminum Else 2. The product is made of a wrought alloy based on aluminum, characterized in that it is made of an alloy containing in wt.%: Manganese 0.5-1.7, calcium 0.002-0.5, sodium 0.0002-0, 01 and at least one metal selected from the group comprising iron, copper, zirconium and chromium 0.02-1.0, aluminum - the rest.