Cast-rolling process for controlling water ripple defect of cast-rolled plate surface

Abstract

The invention provides a cast-rolling process for controlling the water ripple defect of a cast-rolled plate surface, and the cast-rolled plate surface is prepared from the following raw materials in percentage by mass: 0.2-0.25% of Mn; 0.25 to 0.45 percent of Mg; 0.03 to 0.06 percent of Cr; 0.01 to 0.06 percent of Ti; the invention relates to the technical field of cold rolling, in the rolling process, the mode that the front tension is larger than the rear tension is adopted, a flat strip is preferably pulled, meanwhile, during acid pickling, the temperature of acid liquor is increased, the acid pickling speed is reduced, the acid pickling time is shortened, the acid pickling quality is improved, and therefore the better acid pickling quality is obtained; the lubricating requirement is met, metal flow forming is facilitated, and it is guaranteed that oil stains on the plate face are easy to clean.

Description

Technical Field

[0001] The invention relates to the technical field of cold rolling, in particular to a casting and rolling process for controlling water ripple defects on the surface of a cast and rolled plate. Background Art

[0002] Cold rolling is processed from hot rolled plates at room temperature. Although the aluminum plate will heat up due to rolling during the processing, it is still called cold rolling. Cold rolling, which is formed by continuous cold deformation of hot rolled plates, has poor mechanical properties and too high hardness. It must be annealed to restore its mechanical properties. The unannealed ones are called hard rolled coils. Hard rolled coils are generally used to make products that do not require bending or stretching. Hard rolled coils with a thickness of less than 1.0 can be bent on two or four sides if you are lucky.

[0003] Cold rolling uses hot-rolled aluminum coil as raw material, and then cold rolling is carried out after pickling to remove the oxide scale. The finished product is hard rolled coil. The cold work hardening caused by continuous cold deformation increases the strength and hardness of the hard rolled coil, and the toughness and plasticity index decreases. Therefore, the stamping performance will deteriorate and it can only be used for parts with simple deformation. Due to the process characteristics of cold rolling, annealing must be carried out to soften the aluminum when it is rolled to one end. However, during the rolling process, there is lubricating oil on the surface of the aluminum strip, and the grease will evaporate in the annealing furnace. The black spots formed by the volatiles remaining on the surface of the aluminum strip are difficult to remove. Summary of the invention

[0004] In order to overcome the existing problems, an embodiment of the present application provides a casting and rolling process for controlling the water ripple defects on the cast and rolled plate surface. In the present invention, during the rolling process, the front tension is greater than the rear tension, so as to pull the flat strip. At the same time, the acid solution temperature is increased and the pickling speed is reduced during pickling, which reduces the pickling time and improves the pickling quality, thereby obtaining better pickling quality, which meets the lubrication requirements, is beneficial to metal flow forming, and ensures that the oil stains on the plate surface are easy to clean.

[0005] The technical solution adopted by the embodiment of the present application to solve the technical problem is:

[0006] A casting and rolling process for controlling water ripple defects on the surface of a cast and rolled plate. The plate is prepared from the following raw materials in percentage by mass: Mn: 0.2-0.25%; Mg: 0.25-0.45%; Cr: 0.03-0.06%; Ti: 0.01-0.06%; Fe: 0.4-0.6%, and the rest are Al and unavoidable impurity elements.

[0007] The steps of the casting and rolling process for controlling the water ripple defects on the cast and rolled plate surface are as follows:

[0008] Step 1: Raw material processing

[0009] The raw materials of each component weight percentage are added into the melting furnace for melting, and then formed into a casting billet through a mold, and the casting billet is subjected to recrystallization annealing treatment to eliminate intracrystalline segregation and coarse grain structure defects caused by casting and rolling;

[0010] Step 2: Pickling

[0011] The blank is passed through a continuous pickling unit to remove the aluminum oxide skin to ensure that the surface of the aluminum strip is smooth and soft. The pickling acid temperature is 60-90°C and the pickling speed is 2.5-4.5m / min.

[0012] Step 3: Rolling

[0013] The billet is continuously rolled using a casting and rolling mill. During rolling, the front tension is greater than the rear tension to ensure the cold-rolled plate shape. The rolling speed is controlled at 1.2-1.5 m / min.

[0014] Step 4: Annealing

[0015] Heat the blank to 700-750℃, keep it warm for 8h, and then cool it. Before annealing, wash the grease on the surface and anneal it at low temperature for a long time. The cooling method is to use cooling equipment to cool it at a speed of 20-40℃ / s to a red-return temperature of 670-710℃.

[0016] Place in air cooling, air cooling to 500-670℃, until room temperature;

[0017] Step 5: Leveling

[0018] The convex roller is used for leveling to reduce or eliminate edge ridges.

[0019] Preferably, the rolling tension formula in step 3 is as follows:

[0020] Take the tension T = k × as × b × h

[0021] Where: k is the tension coefficient. When the plate thickness is 0.3 to 1 mm, k = 0.5 to 0.8

[0022] When the plate thickness is 1 to 2 mm, k = 0.2 to 0.5

[0023] When the plate thickness is 2 to 4 mm, k = 0.1 to 0.2

[0024] as is the yield strength

[0025] b is the board width

[0026] h is the plate thickness.

[0027] The advantages of the embodiments of the present application are:

[0028] In the present invention, during the rolling process, the front tension is greater than the rear tension, so as to appropriately pull the flat strip. At the same time, the acid solution temperature is increased and the pickling speed is reduced during pickling, so the pickling time is reduced and the pickling quality is improved, thereby obtaining a better pickling quality, which satisfies the lubrication requirements, is beneficial to the metal flow forming, and ensures that the oil stains on the plate surface are easy to clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a schematic diagram of the casting and rolling process flow for controlling water ripple defects on the cast and rolled plate surface. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, for the convenience of description below, the referenced "upper", "lower", "left", and "right" are the same as the upper, lower, left, and right directions of the drawings themselves. The "first", "second", etc. below are distinguished for the description and have no other special meanings.

[0031] The embodiment of the present application solves the problems in the prior art by providing a casting and rolling process for controlling the water ripple defects on the cast and rolled plate surface. In the present invention, during the rolling process, the front tension is greater than the rear tension, so as to pull the flat plate strip. At the same time, the acid solution temperature is increased and the pickling speed is reduced during pickling, which reduces the pickling time and improves the pickling quality, thereby obtaining better pickling quality, which satisfies the lubrication requirements, is beneficial to metal flow forming, and ensures that the oil stains on the plate surface are easy to clean.

[0032] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows:

[0033] Example 1

[0034] This embodiment provides a casting process for controlling the water ripple defects on the cast plate surface. Figure 1 As shown, it is prepared from the following raw materials in mass percentage: Mn: 0.25%; Mg: 0.45%; Cr: 0.06%; Ti: 0.06%; Fe: 0.6%, and the rest are Al and inevitable impurity elements.

[0035] The steps of the casting process for controlling the water ripple defect on the cast plate surface are as follows:

[0036] Step 1: Raw material processing

[0037] The raw materials of each component weight percentage are added into the melting furnace for melting, and then formed into a casting billet through a mold, and the casting billet is subjected to recrystallization annealing treatment to eliminate intracrystalline segregation and coarse grain structure defects caused by casting and rolling;

[0038] Step 2: Pickling

[0039] The blank is passed through a continuous pickling unit to remove the aluminum oxide skin to ensure that the surface of the aluminum strip is smooth and soft. The pickling acid temperature is 60°C and the pickling speed is 2.5m / min.

[0040] Step 3: Rolling

[0041] The billet is continuously rolled using a casting and rolling mill. During rolling, the front tension is greater than the rear tension to ensure the cold-rolled plate shape. The rolling speed is controlled at 1.2m / min.

[0042] Step 4: Annealing

[0043] Heat the blank to 700℃, keep it warm for 8h, and then cool it. Before annealing, clean the grease on the surface and use low temperature and long time annealing. The cooling method is to use cooling equipment to cool it at a speed of 20℃ / s to the red-return temperature of 670℃;

[0044] Place in air cooling, air cooling to 500℃, until room temperature;

[0045] Step 5: Leveling

[0046] The convex roller is used for leveling to reduce or eliminate edge ridges.

[0047] The rolling tension formula in step 3 is as follows:

[0048] Take the tension T = k × as × b × h

[0049] Where: k is the tension coefficient. When the plate thickness is 0.3 to 1 mm, k = 0.5 to 0.8

[0050] When the plate thickness is 1 to 2 mm, k = 0.2 to 0.5

[0051] When the plate thickness is 2 to 4 mm, k = 0.1 to 0.2

[0052] as is the yield strength

[0053] b is the board width

[0054] h is the plate thickness.

[0055] Example 2

[0056] This embodiment provides a casting process for controlling the water ripple defects on the cast plate surface. Figure 1As shown, it is prepared from the following raw materials in mass percentage: Mn: 0.25%; Mg: 0.45%; Cr: 0.06%; Ti: 0.06%; Fe: 0.6%, and the rest are Al and inevitable impurity elements.

[0057] The steps of the casting process for controlling the water ripple defect on the cast plate surface are as follows:

[0058] Step 1: Raw material processing

[0059] The raw materials of each component weight percentage are added into the melting furnace for melting, and then formed into a casting billet through a mold, and the casting billet is subjected to recrystallization annealing treatment to eliminate intracrystalline segregation and coarse grain structure defects caused by casting and rolling;

[0060] Step 2: Pickling

[0061] The blank is passed through a continuous pickling unit to remove the aluminum oxide skin to ensure that the surface of the aluminum strip is smooth and soft. The pickling acid temperature is 90°C and the pickling speed is 2.5m / min.

[0062] Step 3: Rolling

[0063] The billet is continuously rolled using a casting and rolling mill. During rolling, the front tension is greater than the rear tension to ensure the cold-rolled plate shape. The rolling speed is controlled at 1.2m / min.

[0064] Step 4: Annealing

[0065] Heat the blank to 700℃, keep it warm for 8h, and then cool it. Before annealing, clean the grease on the surface and use low temperature and long time annealing. The cooling method is to use cooling equipment to cool it at a speed of 20℃ / s to the red-return temperature of 670℃;

[0066] Place in air cooling, air cooling to 500℃, until room temperature;

[0067] Step 5: Leveling

[0068] The convex roller is used for leveling to reduce or eliminate edge ridges.

[0069] The rolling tension formula in step 3 is as follows:

[0070] Take the tension T = k × as × b × h

[0071] Where: k is the tension coefficient. When the plate thickness is 0.3 to 1 mm, k = 0.5 to 0.8

[0072] When the plate thickness is 1 to 2 mm, k = 0.2 to 0.5

[0073] When the plate thickness is 2 to 4 mm, k = 0.1 to 0.2

[0074] as is the yield strength

[0075] b is the board width

[0076] h is the plate thickness.

[0077] Combining Example 1 and Example 2, it can be seen that:

[0078] In Example 1 and Example 2, the mass fraction of each component is the same, the acid solution temperature in step 1 is 60°C during pickling, and the acid solution temperature in Example 2 is 90°C. At the same time, the pickling speed is the same. In Example 1 where the acid solution temperature is higher, the pickling time is reduced and the pickling quality is improved, thereby obtaining better pickling quality.

[0079] Example 3

[0080] This embodiment provides a casting process for controlling the water ripple defects on the cast plate surface. Figure 1 As shown, it is prepared from the following raw materials in mass percentage: Mn: 0.2%; Mg: 0.25%; Cr: 0.03%; Ti: 0.01%; Fe: 0.4%, and the rest are Al and unavoidable impurity elements.

[0081] The steps of the casting process for controlling the water ripple defect on the cast plate surface are as follows:

[0082] Step 1: Raw material processing

[0083] The raw materials of each component weight percentage are added into the melting furnace for melting, and then formed into a casting billet through a mold, and the casting billet is subjected to recrystallization annealing treatment to eliminate intracrystalline segregation and coarse grain structure defects caused by casting and rolling;

[0084] Step 2: Pickling

[0085] The blank is passed through a continuous pickling unit to remove the aluminum oxide skin to ensure that the surface of the aluminum strip is smooth and soft. The pickling acid temperature is 90°C and the pickling speed is 2.5m / min.

[0086] Step 3: Rolling

[0087] The billet is continuously rolled using a casting and rolling mill. During rolling, the front tension is greater than the rear tension to ensure the cold-rolled plate shape. The rolling speed is controlled at 1.2m / min.

[0088] Step 4: Annealing

[0089] Heat the blank to 700℃, keep it warm for 8h, and then cool it. Before annealing, clean the grease on the surface and use low temperature and long time annealing. The cooling method is to use cooling equipment to cool it at a speed of 20℃ / s to the red-return temperature of 670℃;

[0090] Place in air cooling, air cooling to 500℃, until room temperature;

[0091] Step 5: Leveling

[0092] The convex roller is used for leveling to reduce or eliminate edge ridges.

[0093] The rolling tension formula in step 3 is as follows:

[0094] Take the tension T = k × as × b × h

[0095] Where: k is the tension coefficient. When the plate thickness is 0.3 to 1 mm, k = 0.5 to 0.8

[0096] When the plate thickness is 1 to 2 mm, k = 0.2 to 0.5

[0097] When the plate thickness is 2 to 4 mm, k = 0.1 to 0.2

[0098] as is the yield strength

[0099] b is the board width

[0100] h is the plate thickness.

[0101] In combination with Example 2 and Example 3, it can be seen that: in Example 2 and Example 3, the mass fractions of the components are different, the acid solution temperature in step 1 is 90°C during pickling, and the acid solution temperature in Example 2 is 90°C. At the same time, the pickling speed is the same, and the pickling time is reduced and the pickling quality is improved in Example 2 and Example 3 with the same acid solution temperature, thereby obtaining better pickling quality.

[0102] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface, characterized in that: The above-mentioned is prepared from the following raw materials according to mass percentage: Mn: 0.2-0.25%; Mg: 0.25~0.45%; Cr: 0.03~0.06%; Ti: 0.01~0.06%; Fe: 0.4~0.6%, and the rest are Al and inevitable impurity elements.

2. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 1, characterized in that: The steps of the casting and rolling process for controlling the water ripple defects on the cast and rolled plate surface are as follows: Step 1: Raw material processing The raw materials of each component weight percentage are added into the melting furnace for melting, and then formed into a casting billet through a mold, and the casting billet is subjected to recrystallization annealing treatment to eliminate intracrystalline segregation and coarse grain structure defects caused by casting and rolling; Step 2: Pickling The blank is passed through a continuous pickling unit to remove the aluminum oxide skin to ensure that the surface of the aluminum strip is smooth and soft; Step 3: Rolling The billet is continuously rolled using a casting and rolling mill. During rolling, the front tension is greater than the rear tension to ensure the shape of the cold-rolled plate. Step 4: Annealing Heat the blank to 700-750°C, keep it warm for 8 hours, and then cool it; Step 5: Leveling The convex roller is used for leveling to reduce or eliminate edge ridges.

3. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 2, characterized in that: The acid solution temperature of the pickling in step 2 is 60-90° C., and the pickling speed is 2.5-4.5 m / min.

4. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 2, characterized in that: The rolling speed in step three is controlled at 1.2-1.5 m / min.

5. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 2, characterized in that: The rolling tension formula in step 3 is as follows: Take the tension T = k × as × b × h Where: k is the tension coefficient. When the plate thickness is 0.3 to 1 mm, k = 0.5 to 0.8 When the plate thickness is 1 to 2 mm, k = 0.2 to 0.5 When the plate thickness is 2 to 4 mm, k = 0.1 to 0.2 as is the yield strength b is the board width h is the plate thickness.

6. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 2, characterized in that: In the step 4, before the annealing treatment, the grease on the surface is washed off and low temperature and long time annealing is adopted.

7. A casting and rolling process for controlling water ripple defects on the cast and rolled plate surface as claimed in claim 2, characterized in that: The cooling method in step 4 is to use a cooling device to cool at a rate of 20 to 40°C / s to a red-return temperature of 670 to 710°C; Allow to air cool to 500-670°C until it reaches room temperature.

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