CN109930038B - A kind of deformation heat treatment method of Al-Mg-Zn alloy plate - Google Patents

Abstract

The invention discloses a deformation heat treatment method for an Al-Mg-Zn alloy plate, belonging to the technical field of aluminum alloy heat treatment. Al-Mg-Zn alloy hot-rolled sheets were cold-rolled, followed by recrystallization annealing at 370-380°C for 70-80min; after cooling, the first cold-rolling was performed, using multi-pass cold-rolling with a deformation of 20% ‑70%. After the first cold rolling, an intermediate annealing treatment is performed, the annealing temperature is 200-280° C., and the annealing time is 0.5-4 h; after the annealing, the second cold rolling is performed, and the deformation amount is 0%-50%. Through the heat treatment process of deformation, low temperature heat treatment and re-deformation, the invention promotes the uniform precipitation of T phase in the grain, and through two cold rolling deformation, the alloy has good corrosion resistance and excellent mechanical properties. In addition, the production process is simple, easy to operate, and suitable for industrial production. The problems of poor mechanical properties and unsatisfactory corrosion resistance of the existing Al-Mg-Zn alloy plates are solved.

Description

A kind of deformation heat treatment method of Al-Mg-Zn alloy plate

technical field

The invention belongs to the technical field of aluminum alloy heat treatment, and in particular relates to a deformation heat treatment process method for improving the strength and corrosion resistance of an aluminum alloy plate.

Background technique

With the development of the shipping industry, people's requirements for the mechanical properties and corrosion resistance of aluminum alloys for ships are constantly improving. In order to meet the requirements for performance, the content of Mg and Zn elements in aluminum alloy sheets for ships is also increasing. . The increase of Mg content improves the mechanical properties of the alloy to a certain extent, but when the Mg content is greater than 3%, Mg atoms preferentially precipitate β-Al ₃ Mg ₂ at the grain boundaries. Since the potential of the β phase is lower than the potential of the substrate, corrosion occurs preferentially, which reduces the corrosion resistance of the Al-Mg alloy to a certain extent. At present, the AA5059 alloy, which is widely used in the world, has improved mechanical properties (the yield strength of H321/116 alloy is 370MPa, the tensile strength is 270MPa, and the elongation is 10%) and corrosion resistance. The invention patent ZL201410117124.8 is based on the AA5059 alloy, and by optimizing the content of Mg and Zn in the alloy, a new type of Al-Mg-Zn series alloy, namely 5B59 alloy, is announced. The yield strength of the alloy reaches 270-280 MPa, the tensile strength reaches 370-390 MPa, and the mass loss of intergranular corrosion is less than 15 mg/cm ² . ZL201410381094.1 significantly improves the strength of the alloy by increasing the cold rolling deformation before the stabilization treatment of the above-mentioned alloy, while maintaining the corrosion resistance and 10% elongation. The yield strength reaches 320-350MPa, and the tensile strength reaches 400-415MPa. Nevertheless, the above alloys are still difficult to meet the high strength and still difficult to meet the needs of the continuous development of the shipbuilding industry.

5xxx series aluminum alloys are non-heat treatable strengthening alloys, which mainly rely on the solid solution strengthening of Mg atoms and cold work hardening to strengthen the alloys. Therefore, the general processing technology of aluminum alloy sheets for ships at this stage is: (1) Deformation treatment: cold rolling is a process method to increase deformation. Although this treatment method can effectively improve the mechanical properties of the alloy, since the alloy is not subjected to any heat treatment after cold rolling, the state of the alloy is relatively unstable, and it is not suitable for the production of long-term service alloy sheets; (2) Deformation + stabilization Treatment: The process of stabilizing annealing after one cold rolling. This treatment method performs stabilization annealing after cold rolling, which improves the corrosion resistance of the alloy. However, due to the recovery and partial recrystallization during the annealing process, the mechanical properties of the alloy tend to decline relatively. In view of the deficiencies of the above two existing processes, the present invention proposes a new production and processing process for Al-Mg alloy plates, which can solve the problems existing in the prior art and obtain alloys with excellent mechanical properties and corrosion resistance at the same time. plate.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a deformation heat treatment process for a corrosion-resistant Al-Mg-Zn alloy plate. Through this process, the aluminum alloy has excellent mechanical properties and also has good corrosion resistance.

A deformation heat treatment method for an Al-Mg-Zn alloy plate, comprising the following steps:

(1) Cold-rolling the Al-Mg-Zn alloy hot-rolled sheet, followed by recrystallization annealing at 370-380°C for 70-80min;

(2) cold-rolling the aluminum alloy sheet obtained in step (1) for the first time, adopting multi-pass cold-rolling, and the deformation amount is 20%-70%;

(3) performing intermediate annealing treatment on the aluminum alloy cold-rolled sheet obtained in step (2), the annealing temperature is 200-280°C, and the annealing time is 0.5-4h;

(4) The second cold rolling is performed on the aluminum alloy sheet obtained in step (3), and the cold rolling deformation amount is 0%-50%.

Further, the deformation amount of the first cold rolling in step (2) is 40%-60%.

Further, the intermediate annealing temperature in step (3) is 250°C-280°C for 1-2 hours.

Further, the deformation amount of the second cold rolling in step (4) is 5%-20%.

Further, the chemical composition of the alloy as mentioned above is 4.0-7.0Mg, 0-2Zn, 0-0.4Cu, 0-1.0Mn, 0-0.15Ti, 0-0.2Zr, 0-0.4Fe, 0-0.4Si, The remainder is Al.

The treatment method can effectively improve the microstructure of the Al-Mg(-Zn) alloy: by promoting the uniform precipitation of β phase or T phase in the grain and intermittent precipitation in the grain boundary, the corrosion resistance of the alloy can be effectively improved. Through the first large cold rolling deformation and the second cold rolling after intermediate annealing, the alloy has a good work hardening effect and obtains better mechanical properties. Therefore, the alloy sheet obtained by this deformation heat treatment process usually has better stability and corrosion resistance compared with the simple cold rolling process; compared with the deformation + stabilization process, it has higher mechanical properties. It makes up for the deficiencies of the existing production and processing technology, and then obtains an alloy sheet with excellent mechanical properties and corrosion resistance at the same time. The production process is simple, easy to operate, and suitable for industrial production.

Detailed ways

The present invention will be further elaborated below in conjunction with comparative examples and examples.

Three kinds of Al-Mg alloys were smelted in the laboratory, and their chemical compositions are shown in Table 1. The alloys were homogenized and annealed and hot rolled to 6 mm. Different deformation heat treatment processes were used for the hot-rolled sheets, as shown in Table 2. Then, the plate was kept at 100 °C for 7 d for sensitization treatment.

Table 1 Specific chemical composition (wt%) of the implementation alloy

Alloy number Mg Zn Mn Cu Cr Zr Ti Fe Si 1# 5.80 0.00 0.50 0.05 0.03 0.15 0.07 0.15 0.15 2# 5.80 1.00 0.50 0.05 0.03 0.15 0.07 0.15 0.15 3# 5.80 1.00 0.50 - 0.03 0.15 0.07 - -

Table 2 Preparation methods used for alloys 1# and 2#

Comparative Example 1:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm.

Comparative Example 2:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm.

Comparative Example 3:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.33mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 25%, and the final rolling thickness is 2.5 mm.

Comparative Example 4:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.75mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Comparative Example 5:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.85mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 35%, and the final rolling thickness is 2.5 mm.

Comparative Example 6:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.17mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 40%, and the final rolling thickness is 2.5 mm.

Comparative Example 7:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 45%, and the final rolling thickness is 2.5 mm.

Comparative Example 8:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.00mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 50%, and the final rolling thickness is 2.5 mm.

Comparative Example 9:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.56mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 55%, and the final rolling thickness is 2.5 mm.

Comparative Example 10:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment.

Comparative Example 11:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment.

Comparative Example 12:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment.

Comparative Example 13:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment.

Comparative Example 14:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment.

Comparative Example 15:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 3.13mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 20%, and the final rolling thickness is 2.5 mm. Then, the alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment.

Comparative Example 16:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 17:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 18:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 19:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Comparative Example 20:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Comparative Example 21:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Comparative Example 22:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 23:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 24:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Comparative Example 25:

The 6mm thick 1# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 270 °C for 1 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 1:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 2:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 3:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.27mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 35%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 4:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Example 5:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Example 6:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 4.46mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 3.57 mm with a deformation of 20%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 30%, and the final rolling thickness is 2.5 mm.

Example 7:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.68mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 4.54 mm with a deformation of 20%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 45%, and the final rolling thickness is 2.5 mm.

Example 8:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.68mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 4.54 mm with a deformation of 20%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 45%, and the final rolling thickness is 2.5 mm.

Example 9:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.68mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 4.54 mm with a deformation of 20%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 45%, and the final rolling thickness is 2.5 mm.

Example 10:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 210 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 11:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 240 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 12:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 270 °C for 2 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Example 13:

The 6mm thick 2# alloy hot rolled sheet was cold rolled to 5.55mm. Subsequently, recrystallization annealing was performed at 375 °C for 75 min. The alloy sheet was cold rolled to 2.78 mm with a deformation of 50%. The alloy plate was kept at 270 °C for 1 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 10%, and the final rolling thickness is 2.5 mm.

Table 3 Mechanical properties and corrosion resistance of alloys 1# and 2# under different processes

Table 3 lists the hardness, strength and intergranular corrosion weight loss (measured according to ASTMG66 method) of the alloy plates prepared by the above method. The results show that, compared with the "traditional deformation treatment" process of Comparative Examples 1-9, although the strength of the alloy after deformation heat treatment is slightly decreased, the intergranular corrosion resistance has been significantly improved; Compared with the "deformation + stabilization treatment" process, the alloy effectively enhances the mechanical properties while ensuring that the corrosion resistance is not reduced. The results show that the first cold rolling with a large deformation (50%) combined with the stabilization annealing at a higher temperature (270℃/1h) can make the T phase precipitate uniformly in the grain, and the grain boundary is intermittently precipitated. A second cold rolling with a small deformation (5-10%) compensates for the strength lost by the stabilization annealing. The lowest weight loss value of the alloy after sensitization reaches 31 mg/cm ² , which is significantly better than that of other alloys. The above experimental results show that the deformation heat treatment process can effectively make up for the shortcomings of the existing production process, so that the mechanical properties and corrosion resistance of the Al-Mg alloy can be improved at the same time. Table 4 lists the processing and preparation process of alloy 3#.

Table 4 Preparation technology used for alloy 3#

example Alloy number How to handle Comparative Example 26 3# Cold rolling deformation (50%)+270℃/1h Comparative Example 27 3# Cold rolling deformation (60%)+270℃/1h Example 24 3# The first cold rolling deformation (50%)+270℃/1h+the first cold rolling deformation (5%)

Comparative Example 26:

The 6mm thick 3# alloy hot-rolled sheet was held at 375°C for 75min for recrystallization annealing. Then, the alloy plate was subjected to cold rolling deformation with a deformation amount of 50%, and the final rolling thickness was 3.0 mm. Then, the alloy plate was kept at 270 °C for 1 h for stabilization annealing treatment.

Comparative Example 27:

The 6mm thick 3# alloy hot-rolled sheet was held at 375°C for 75min for recrystallization annealing. Then, the alloy sheet is subjected to cold rolling deformation with a deformation amount of 60%, and the final rolling thickness is 2.4 mm. Then, the alloy plate was kept at 270 °C for 1 h for stabilization annealing treatment.

Example 24:

The 6mm thick 3# alloy hot-rolled sheet was held at 375°C for 75min for recrystallization annealing. The alloy sheet was cold rolled to 3.0 mm with a deformation of 50%. The alloy plate was kept at 270 °C for 1 h for stabilization annealing treatment. Then, the alloy sheet is cold-rolled for the second time with a deformation amount of 5%, and the final rolling thickness is 2.85 mm.

Table 5 Mechanical properties and corrosion resistance of alloy 3#

The process parameters described in the present invention are not limited to several specific processes selected in the embodiments, and the same effect can be achieved within the parameter range.

Claims (3)

1. a deformation heat treatment method of Al-Mg-Zn alloy plate, is characterized in that, comprises the following steps: (1) Cold-rolling the Al-Mg-Zn alloy hot-rolled sheet, followed by recrystallization annealing at 370-380°C for 70-80min; (2) cold-rolling the aluminum alloy sheet obtained in step (1) for the first time, using multi-pass cold-rolling, and the deformation amount is 20%-70%; (3) performing intermediate annealing treatment on the aluminum alloy cold-rolled sheet obtained in step (2), the annealing temperature is 200-280°C, and the annealing time is 0.5-4h; (4) the second cold rolling is carried out to the aluminum alloy sheet obtained in step (3), and the cold rolling deformation is 10%-50%; The chemical composition of the alloy is 4.0-7.0Mg, 1-2Zn, 0.05-0.4Cu, 0.5-1.0Mn, 0.07-0.15Ti, 0.15-0.2Zr, 0.15-0.4Fe, 0.15-0.4Si, and the balance is Al . 2. The deformation heat treatment method of the Al-Mg-Zn alloy sheet according to claim 1 is characterized in that the first cold rolling deformation of step (2) is 40%-60%. 3. The deformation heat treatment method of the Al-Mg-Zn alloy plate according to claim 1, characterized in that the intermediate annealing temperature of step (3) is 250 ℃-280 ℃ for 1-2h.