CN113373389A - Method for controlling intermediate annealing oil spots of aluminum alloy coiled material - Google Patents

Abstract

The invention provides a method for controlling intermediate annealing oil spots of an aluminum alloy coiled material, which comprises the following steps: A) cold rolling the aluminum alloy at the speed of less than or equal to 0.5 m/s; B) annealing the aluminum alloy after cold rolling; the blowing and washing temperature in the annealing process is 180-210 ℃, the air pressure circulation mode of the annealing treatment is side suction, and the temperature of the annealing material of the annealing treatment is 300-330 ℃. This application has been injectd through speed, the annealing in-process that blasts temperature and time, annealing material temperature and wind pressure circulation mode to cold rolling, and final effective control oil spot has improved the surface quality of aluminum alloy coiled material.

Description

Method for controlling intermediate annealing oil spots of aluminum alloy coiled material

Technical Field

The invention relates to the technical field of aluminum alloy, in particular to a method for controlling intermediate annealing oil spots of an aluminum alloy coiled material.

Background

The oil spots on the surface of the rolled aluminum plate and strip are always a key problem which troubles aluminum processing enterprises. After high-temperature annealing, the surface of the coiled material presents wave-shaped light yellow or tawny oil spots along the width direction of the plate, and even if the cold rolling is carried out repeatedly, the oil spots on the surface can not be completely eliminated, thereby affecting the appearance quality of the product.

In the preparation process of the aluminum alloy strip, oil spots are chemical reactants, after cold rolling, rolling oil undergoes catalytic reaction, easily-oxidizable substances such as olefin, hydrocarbon, aromatic hydrocarbon, sulfur and the like in the rolling oil undergo oxidative deterioration in different degrees and are polymerized into colloid with larger molecular weight, the colloid is difficult to volatilize in the annealing process, and the colloid remains on the surface of the aluminum strip and is incompletely combusted with the atmosphere in a furnace to form the oil spots.

Ideally, the cold rolling surface is flat and smooth, and no rolling oil is left on the surface, but because the rolling mill equipment in the current rolling mill is seriously aged, the plate shape control means is few, and the plate shape can be controlled only by bending rolls and manually adjusting the rolling reduction, the control variable of the residual oil on the surface is large, so that annealing oil spots are easily formed.

Disclosure of Invention

The invention aims to provide a method for controlling intermediate annealing oil spots of an aluminum alloy coiled material, which can obviously prevent and control the generation of the oil spots and improve the surface quality of the aluminum alloy coiled material.

In view of the above, the present application provides a method for controlling inter-annealing oil spots of an aluminum alloy coil, comprising the following steps:

A) cold rolling the aluminum alloy at the speed of less than or equal to 0.5 m/s;

B) annealing the aluminum alloy after cold rolling; the blowing and washing temperature in the annealing process is 180-210 ℃, the air pressure circulation mode in the annealing process is side suction, and the annealing material temperature in the annealing process is 300-330 ℃.

Preferably, the distillation range of the rolling oil in the cold rolling process is 220-280 ℃.

Preferably, the purging time in the annealing process is 0.5-2 h.

Preferably, the wind pressure circulation mode of the annealing treatment is a side suction mode from left to right.

Preferably, the annealing process specifically comprises:

the purging constant temperature is 210 ℃, the purging time is 120min, the first constant temperature is 460 ℃, the first heating time is 330min, the second constant temperature is 300-330 ℃, and the second heating time is 210 min.

Preferably, the purge temperature is 210 ℃.

Preferably, the material temperature of the annealing treatment is 330 ℃.

The application provides a method for controlling intermediate annealing oil spots of an aluminum alloy coil, which greatly improves the formation of annealing oil spots and improves the surface quality of the aluminum alloy coil by controlling the parameters of four directions, namely a cold rolling speed, a wind pressure circulation mode in the annealing process, a blow washing temperature in the annealing process and an annealing material temperature of annealing treatment.

Drawings

FIG. 1 is a photograph of a real object of the present invention in which the rolling speed has an influence on the annealing oil spot;

FIG. 2 is a photograph of an object of the present invention in which the effect of temperature and time of purging on annealing oil spots during annealing is exhibited;

FIG. 3 is a photograph showing the effect of the wind pressure circulation mode on the annealing oil spots during the annealing process.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In view of the problem of oil spots generated in the annealing process of the aluminum alloy coil, the application provides the method for controlling the intermediate annealing oil spots of the aluminum alloy coil, and the method enables the annealing oil spots to be remarkably controlled and improves the surface quality of the aluminum alloy coil by controlling the related parameters of the cold rolling speed, the blow washing temperature, the wind pressure circulation mode and the annealing material temperature in the annealing process. Specifically, the embodiment of the invention discloses a method for controlling intermediate annealing oil spots of an aluminum alloy coiled material, which comprises the following steps:

A) cold rolling the aluminum alloy at the speed of less than or equal to 0.5 m/s;

B) annealing the aluminum alloy after cold rolling; the blowing and washing temperature in the annealing process is 180-210 ℃, the air pressure circulation mode of the annealing treatment is side suction, and the temperature of the annealing material of the annealing treatment is 300-330 ℃.

In the process of controlling the intermediate annealing oil spots of the aluminum alloy coiled material, the method firstly controls the aluminum alloy cold rolling stage. The surface residual oil after cold rolling is the main reason for the generation of annealing oil spots, and the surface residual oil amount can not be used as a qualitative index only by visual observation in the production process, so that different cold rolling speeds are controlled on the premise of the same purging according to the rolling condition, and the quality condition of the surface subjected to high-temperature annealing is compared.

TABLE 1 Rolling speed annealing oil spot verification data sheet

Tests prove that the speed of the cold-rolled finished product is controlled below 0.5m/s, rolling residual oil can be volatilized completely, the degree of surface oil spots is obviously reduced, but the oil spots cannot be completely eliminated.

According to the method, the aluminum alloy after cold rolling is annealed, the final distillation point of rolling oil is avoided as much as possible by selecting the blowing and washing temperature in the annealing process, long carbon chain substances in residual oil on the surface of the aluminum alloy plate are combusted with oxygen in a furnace when the final distillation point is exceeded, and obvious annealing oil spots are formed. The method verifies the surface quality of different annealing temperatures to determine the purging temperature and time, and the distillation range of the rolling oil is 220-280 ℃ in the process. Specifically as shown in table 2;

table 2 comparative data table of annealing oil mark experiment

The actual photographs of the above-mentioned groups of samples are shown in FIG. 2, in which FIGS. 2A to 2H correspond to samples No. 1 to No. 8 in Table 2, respectively. By verifying the surface quality at different annealing temperatures, the annealing temperature is the critical point of the volatilization of the rolling oil at 210 ℃, and the surface oil spots are not obvious, so that 210 ℃/2h can be selected as the temperature control for purging the surface residual oil in the annealing temperature process.

The wind pressure circulation mode in the annealing process has certain influence on the volatilization of residual oil on the surface of the coiled material. Therefore, the present application investigated the annealing quality conditions of annealing furnaces of different wind pressure circulation modes, and the results are shown in table 3 and fig. 3, where fig. 3A and fig. 3B in fig. 3 correspond to furnace # 3 and furnace # 1/2, respectively;

TABLE 3 wind pressure circulation mode oil spot verification

Through the test comparison of the annealing quality conditions of annealing furnaces with different wind pressure circulation modes, the surface quality of the side suction type wind pressure circulation mode is obviously better than that of the top suction type wind pressure circulation mode. Therefore, the wind pressure circulation mode can be selected to be the side-suction annealing furnace for production.

Due to the adoption of roll annealing, residual oil on the core part of the coiled material cannot be completely volatilized in a blowing and washing stage due to factors such as tension, plate type and the like, and oil spots can be formed by oxidation after high-temperature annealing.

TABLE 4 annealing material temperature oil spot verification data sheet

The annealing process is adjusted through tests, the constant temperature is reduced, and the surface quality condition can be improved by reducing the material temperature. Therefore, the annealing material temperature can be reduced to carry out production.

In conclusion, the control of the annealing oil spots is realized by controlling the cold rolling speed, controlling the blow washing temperature and time of the annealing furnace, controlling the wind pressure circulation mode of the annealing furnace and controlling the annealing furnace charge, and the surface quality of the aluminum alloy coiled material is improved.

For further understanding of the present invention, the method for controlling the interannealing oil spot of the aluminum alloy coil provided by the present invention is described in detail below with reference to the following examples, and the scope of the present invention is not limited by the following examples.

Examples

The aluminum alloy is cold-rolled, the cold-rolled aluminum alloy is annealed, the specific parameter control and the oil spot appearance of the two stages are shown in the table 5,

TABLE 5 example parameter control and Effect table

The formation of oil spots is closely and inseparably connected with a plurality of factors in the annealing process, and effective results can be obtained only by comprehensively remedying from the aspects of equipment, production and process control. The above examples demonstrate that the control of the cold rolling speed, the selection of annealing equipment and the adjustment of the annealing purging temperature and time greatly improve the formation of annealing oil spots.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. A method for controlling intermediate annealing oil spots of an aluminum alloy coiled material comprises the following steps:

A) cold rolling the aluminum alloy at the speed of less than or equal to 0.5 m/s;

B) annealing the aluminum alloy after cold rolling; the blowing and washing temperature in the annealing process is 180-210 ℃, the air pressure circulation mode in the annealing process is side suction, and the annealing material temperature in the annealing process is 300-330 ℃.

2. The method according to claim 1, wherein the distillation range of the rolling oil during the cold rolling is 220-280 ℃.

3. The method according to claim 1, wherein the purging time during the annealing process is 0.5-2 h.

4. The method of claim 1, wherein the annealing treatment is performed in a wind pressure cycling mode from left to right in a side draft mode.

5. The method according to claim 1, wherein the annealing process is specifically:

the purging constant temperature is 210 ℃, the purging time is 120min, the first constant temperature is 460 ℃, the first heating time is 330min, the second constant temperature is 300-330 ℃, and the second heating time is 210 min.

6. The method according to claim 1, characterized in that the purging temperature is 210 ℃.

7. The method of claim 1, wherein the material temperature of the annealing treatment is 330 ℃.

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