RU2801806C1 - METHOD FOR PRODUCING CLAD SHEETS FROM AN ALLOY BASED ON THE Al-Cu-Mg-Mn SYSTEM - Google Patents

Abstract

FIELD: metal industry.

SUBSTANCE: invention relates to the production of clad sheets from high-strength aluminium alloys, namely alloys based on the Al-Cu-Mg-Mn system, used as a structural material in aircraft. Cladding plates from an alloy of the Al-Mg-Si system are welded to the base layer from an alloy of the Al-Cu-Mg-Mn system. Cladding boards are preliminarily obtained by hot rolling a three-layer package consisting of a central layer of a cladding alloy of the Al-Mg-Si system, coated on both sides with technical aluminium sheets of a given thickness. Then the resulting cladding plates are placed on both sides of the workpiece from an alloy of the Al-Cu-Mg-Mn system and they are welded by hot rolling. Preliminary heating of the package upon receipt of cladding plates and when welding cladding plates to the main layer is carried out at a temperature of 420-465°C for 4-12 hours, and hot rolling - at a temperature of 380-465°C.

EFFECT: method provides defect-free welding of the cladding layer to the base Al-Cu-Mg-Mn alloy.

1 cl, 1 tbl, 1 ex

Description

The invention relates to the field of metallurgy, and in particular to methods for producing clad sheets from alloys based on the Al-Cu-Mg-Mn system used as a structural material in aircraft.

A known method for producing clad sheets from aluminum-based alloys, including alloys of the Al-Cu-Mg-Mn system, in which cladding is carried out by joint hot rolling of a milled cast billet - a slab with AD1 grade aluminum plates superimposed on it on both sides ( see "Aluminum alloys. Production of semi-finished products from aluminum alloys. Reference guide. Iz-vo "Metallurgy", 1971, pp. 55-57).

The disadvantage of this method is the reduced strength of the clad sheets due to the low strength of the material of the cladding layer.

A known method for producing clad sheets from alloys based on aluminum of the Al-Cu-Mg-Mn system, which consists in casting an ingot by a semi-continuous method, homogenizing, subjecting to machining, applying AD35 alloy plates on both sides of the workpiece and carrying out joint hot and then cold rolling (article Antipov V.V., Chertovikov V.M., Tkachenko E.A., Gorokhov V.P. Development and research of large-sized sheathing sheets of brand 1163 RDTV with regulated hard cladding and improved service characteristics compared to similar characteristics of serial sheets". "Non-ferrous metals" 2013. No. 9).

The disadvantage of the known method is the formation of defects in the form of subplate bubbles, discontinuities located between the base metal and the cladding metal, which reduces the yield in the production of clad sheets from aluminum alloys based on the Al-Cu-Mg-Mn system.

The claimed method for producing clad sheets from aluminum alloys based on the Al-Cu-Mg-Mn system, which provides reliable defect-free welding of the cladding coating to the base metal and consists in applying a cladding coating using a specially prepared plate obtained by hot rolling a three-layer package consisting of a cladding layer Al-Mg-Si alloy, including AD35, coated on both sides with technical aluminum sheets AD1, providing defect-free welding of the cladding layer to the base Al-Cu-Mg-Mn alloy.

The technical solution of the present invention is to ensure high-quality welding of layers of "hard" cladding from alloys of the Al-Mg-Si system to the main layer of an alloy of the Al-Cu-Mg-Mn system by increasing the weldability of the cladding layer with the base metal during hot rolling, improving the surface quality sheets. The method consists in preparing the package, heating the package before rolling, hot rolling, cooling to room temperature. The package consists of a base layer and cladding layers, while the sheets for cladding layers are obtained by hot rolling and consist of an aluminum alloy layer clad with technical aluminum on both sides.

The task is achieved by the fact that the proposed method for manufacturing sheets from heat-hardened aluminum alloys, including the assembly of a package 1 consisting of a workpiece from an alloy of the Al-Mg-Si system, coated on both sides with sheets (plates) of technical aluminum, hot rolling of the package 1 on a cladding plate, assembly of package 2 consisting of a billet of the base metal from an alloy of the Al-Cu-Mg-Mn system with cladding tablets made of Al-Mg-Si alloy and technical aluminum, hot rolling of package 2 to a given thickness.

Package 1 consists of a base layer and cladding layers, while the sheets for cladding layers are obtained by hot rolling and consist of an aluminum alloy layer clad with aluminum on both sides. Heating of the package before rolling the tablet is carried out at temperatures of 420-465°C for 4-12 hours, rolling to size is carried out at temperatures of 390-465°C. Heating of the package 1 consisting of the main layer and the tablet is carried out at temperatures of 420-465°C for 4-12 hours. Rolling to size is carried out at temperatures of 390-465°C. The thickness of the aluminum alloy cladding layer in the rolled sheet is 1-12% of the sheet thickness.

Package 2 also consists of a base layer and cladding layers, while the sheets for cladding layers are obtained by hot rolling and consist of an aluminum alloy layer clad with aluminum on both sides. Package 2 is heated at temperatures of 420-465°C for 4-12 hours, rolling to size is carried out at temperatures of 380-465°C, cooling is carried out to room temperature.

The assembly of the cladding package 1 is carried out in the following order:

- the top layer is a sheet of technical aluminum with a thickness of 2.2-15% of the thickness of the middle layer;

- middle layer - cast homogenized, milled workpiece from an alloy of the Al-Mg-Si system;

- the bottom layer - a sheet of technical aluminum with a thickness of 2.2-15% of the thickness of the middle layer;

Package 1 is heated at temperatures of 420-465°C for 4-12 hours, rolling in size is carried out at temperatures of 380-465°C, cooling is carried out to room temperature. After hot rolling of package 1, sheets (plates) of a given thickness are obtained, consisting of three layers: a cladding layer of aluminum, a layer of an alloy of the Al-Mg-Si system, a cladding layer of aluminum.

Package 2 is assembled in the following order:

- top layer - cladding plate, consisting of a sheet of Al-Mg-Si alloy with a thickness of 2.2-15% of the thickness of the middle layer, pre-clad from below and above with aluminum;

- middle layer - cast homogenized, milled workpiece from an alloy of the Al-Cu-Mg-Mn system;

- lower layer - cladding plate, consisting of an Al-Mg-Si alloy sheet with a thickness of 2.2-15% of the thickness of the middle layer, pre-clad from below and above with technical aluminum.

Package 2 is heated at temperatures of 410-465°C for 4-12 hours, rolling to size is carried out at a temperature of 380-465°C, cooling is carried out to room temperature.

Depending on the thickness of the rolled products and further processing, a roll or cards are obtained.

Example

For the manufacture of "hard" cladding sheets according to the invention, a "hard" cladding plate was made, then a "hard" cladding sheet was made.

For the manufacture of plates for "hard" cladding of the AD35 alloy, homogenized milled blanks from ingots made by semi-continuous casting were used. From blanks AD35 275 mm thick and an aluminum plate 7 mm thick, a package was assembled, heated to a temperature of 440°C for 6 hours, rolled at temperatures of 440-390°C to a thickness of 7 mm, cooled to room temperature, and the plate was cut. .

For the manufacture of a sheet with a "hard" cladding, homogenized milled blanks from alloy 1163 from ingots made by semi-continuous casting and AD35 alloy plates clad with aluminum were used. From blanks 1163 with a thickness of 270 mm and an AD35 plate with a thickness of 7 mm clad with aluminum, a package was assembled, heated to a temperature of 440°C for 6 hours, rolled at temperatures of 440-390°C to a thickness of 7 mm, cooled to room temperature, and cut sheets for further processing.

The practice of work in recent years has shown that the use of sheets from an alloy of the Al-Mg-Si system pre-clad with technical aluminum makes it possible to provide high-quality defect-free welding of an Al + Al-Mg-Si + Al plate to the base metal from an alloy of the Al-Cu-Mg-Mn system due to the presence on the contacting surfaces of the cladding sheets of the Al-Mg-Si system alloy and Al-Cu-Mg-Mn aluminum system alloy during hot rolling. This method, using intermediate layers of aluminum, makes it possible to obtain sheets with a hard cladding, while there are no (excluded) defects caused by poor welding of the cladding layer of the "hard" cladding to the main layer, such as under tablet bubbles and others.

The table shows the advantage of this method, its economic benefits and improvement in the quality of the hard clad sheet.

Claims (1)

A method for manufacturing clad sheets from high-strength aluminum alloys, which includes welding cladding plates from an alloy of the Al-Mg-Si system to the main layer from an alloy of the Al-Cu-Mg-Mn system, characterized in that the cladding plates are preliminarily obtained by hot rolling a three-layer package consisting from the central layer of the cladding alloy of the Al-Mg-Si system, coated on both sides with technical aluminum sheets, with a thickness of 2.2 to 15% of the thickness of the said central layer, and then the resulting cladding plates are placed on both sides of the workpiece from the alloy of the Al- Cu-Mg-Mn and carry out their welding by hot rolling, while the pre-heating of the package when receiving cladding plates and when welding cladding plates to the main layer is carried out at a temperature of 420-465 ° C for 4-12 hours, and hot rolling - at a temperature 380-465°С.