TWI507256B - Production method of cold rolled products free of electrolytic cleaning - Google Patents

Description

Method for manufacturing cold-rolled product without electrolytic cleaning

The present invention relates to a method for producing a cold rolled steel coil, and more particularly to a method for producing a cold rolled product which is free of electrolytic cleaning.

Referring to FIG. 1, a conventional method for manufacturing a cold rolled steel coil includes a cold rolling step 11, an electrolytic cleaning step 12, an annealing step 13, a quenching and rolling step 14, and a cold rolling finishing step 15.

The cold rolling step 11 is to cold-roll the hot-rolled steel blank 100 into a semi-finished product 101 of a predetermined volume size by using a plurality of tandem cold rolling mills 111; the electrolytic cleaning step 12 is an electrolytic cleaning device 121. Electrolytic washing removes contaminants such as rolling oil, iron powder, etc. remaining on the surface of the semi-finished product 101.

In the annealing step 13, the semi-finished product 101 of the electrolytic cleaning step 12 is sent to an annealing furnace 131, and the semi-finished product 101 is annealed by the high-temperature gas in the annealing furnace 131 to remove the internal portion of the semi-finished product 101 due to rolling. The internal stress; the quenching and rolling step 14 is to roll the semi-finished product 101 by a single-stand rolling mill 141 to adjust the surface roughness, shape and eliminate the Luders Bands of the semi-finished product 101; the cold rolling finishing step 15 is to flatten the semi-finished product by a flattening device 151, and cut and retract the semi-finished product 101 according to a predetermined size in cooperation with a cutting and rewinding device 152 to complete the production of the cold-rolled steel coil.

However, due to the limitation in size, the electrolytic cleaning apparatus 121 can only electrolytically clean the semi-finished product 101 having a thickness of less than 2.0 mm, and the semi-finished product 101 having a thickness of not less than 2.0 mm cannot be electrolytically cleaned. And by the following table It can be seen that the cleanliness of the cold-rolled steel coil after electrolytic cleaning is significantly better than the cleanliness of the cold-rolled steel coil which is not electrolytically cleaned.

The cleanliness of the cold-rolled steel coil not only affects the complexity and difficulty of the subsequent processing, but also relates to the quantity and production cost of the cold-rolled steel coil defective products. Therefore, how to improve the cleanliness of the cold-rolled steel coil that is not electrolytically cleaned has become a target for the related industry.

Accordingly, it is an object of the present invention to provide a method for producing a cold-rolled product which is highly clean and free of electrolytic cleaning.

Therefore, the method for manufacturing the cold-rolled product of the electroless cleaning of the present invention comprises a cold rolling step, an annealing step, a quenching and rolling step, and a cold rolling finishing step.

The cold rolling step is to cold-roll a hot-rolled steel blank into a semi-finished product of a predetermined volume size by using a plurality of tandem cold rolling mills, and spray the cleaning agent from the last cold rolling mill toward the semi-finished product, and the cleaning agent The cation concentration is between 100 ppm and 300 ppm, the pH is between 3.0 and 7.0, the specific gravity is between 1.0 and 1.2, and the flow rate of the cleaning agent is between 5,000 liters per minute and 10,000 liters per minute.

The annealing step is to anneal the semi-finished product by controlling the gas flow rate and the processing time in an annealing device, the annealing step comprising an initial annealing sub-step, a mid-annealing sub-step, and a final annealing sub-step, the initial annealing step The time of the step is between 3 hours and 6 hours, and the gas The volume flow is between 8 cubic meters per hour and 15 cubic meters per hour, and the intermediate annealing step is between 5 hours and 10 hours, and the gas flow rate is 14 cubic meters per hour to hourly. Between 20 cubic meters, the final annealing step is between 3 hours and 6 hours, and the gas flow rate is between 8 cubic meters per hour and 15 cubic meters per hour.

The quenching and rolling step is to use a single-seat rolling mill to roll the semi-finished product to adjust the surface roughness and appearance of the semi-finished product and eliminate the Luda belt. The cold rolling finishing step is to flatten the semi-finished product by using a flattening device, and cut the semi-finished product according to the set size with a cutting device.

The invention has the beneficial effects of controlling the cation concentration, pH value, specific gravity and flow rate of the cleaning agent in the cold rolling step, and controlling the gas flow rate and the processing time in the annealing device in conjunction with the annealing step to improve the cold-free cleaning The cleanliness of the rolled product, which in turn makes the subsequent processing process easier, and also reduces the production of defective products to reduce production costs.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to FIG. 2 and FIG. 3, a preferred embodiment of the method for manufacturing a cold-rolled product for electroless cleaning according to the present invention comprises, in sequence, a cold rolling mill 211 using a plurality of tandem arrangements to cool the hot-rolled steel preform 200. a cold rolling step 21 of rolling the semi-finished product 201 into a predetermined volume size, an annealing step 22 for annealing the semi-finished product 201 by controlling the flow rate of hydrogen in the annealing device 220, and a treatment time, a quenching and rolling step 23, and a Cold rolling finishing step 24.

The last cold rolling mill 211 in the cold rolling step 21 can spray the cleaning agent toward the semi-finished product 201 using the existing nozzle, and the cleaning agent has a cation concentration of between 100 ppm and 300 ppm and a pH of between 3.0 and 7.0. The specific gravity is between 1.0 and 1.2, and the flow rate of the cleaning agent is between 5,000 liters per minute and 10,000 liters per minute, and the cleaning agent is replaced every month.

The cold rolling mills 211 each have a plurality of cold rolling rolls 212 correspondingly arranged to roll the hot rolled steel blanks 200, and the hot rolled steel blanks 200 are passed through the cold rolling rolls 212 of the cold rolling mill 211. The cold rolling roll 212, which is rolled toward the annealing apparatus 220 and which is closest to the cold rolling mill 211 of the annealing apparatus 220, is a chrome-plated cold rolling roll 212 having a thickness of between 0.5 μm and 1.5 μm.

Since the cleaning agent is generally recycled, the cleaning agent can be replaced every month to effectively reduce the possible oil and residual iron in the cleaning agent, and the cold rolling roll 212 that controls the cold rolling mill 211 closest to the annealing device 220 is controlled. The chrome-plated cold rolling roll 212 having a thickness of between 0.5 μm and 1.5 μm can reduce the amount of residual iron generated by roll abrasion.

The annealing step 22 includes an initial annealing sub-step 221, a mid-annealing sub-step 222, and a final annealing sub-step 223. The initial annealing sub-step 221 takes between 3 hours and 6 hours, and the hydrogen flow rate is Between 8m ³ /hr and 15m ³ /hr, and the time of the intermediate annealing sub-step 222 is between 5 hours and 10 hours, and the hydrogen flow rate is between 14m ³ /hr and 20m ³ /hr per hour. The time of the final annealing substep 223 is between 3 hours and 6 hours, and the hydrogen flow rate is between 8 m ³ /hr and 15 m ³ /hr.

The initial annealing sub-step 221, the intermediate annealing sub-step 222 and the final annealing sub-step 223 are used to control the hydrogen flow rate and the processing time in the annealing device 220, so that the rolling oil remaining on the surface of the semi-finished product 201 can be cracked. The hydrocarbons are sufficiently carried away by the hydrogen of the annealing apparatus 220.

The quenching and rolling step 23 is to roll the semi-finished product 201 by a single-stand rolling mill 231 to adjust the surface roughness and appearance of the semi-finished product 201 and eliminate the land tape. The cold rolling finishing step 24 is to level the semi-finished product 201 by using a leveling device 241, and cut the semi-finished product 201 according to the set size with a cutting device 242 to form a cold-rolled product 202.

In the preferred embodiment, the cold rolled product 202 is a cold rolled steel sheet having a thickness of more than 6 mm. Of course, the cold rolled product 202 may also be a cold rolled steel coil having a relatively small thickness, and still have the same effect.

In order to verify the efficacy of the manufacturing method of the present invention, the inventors conducted experiments using the same hot-rolled steel blank 200, and the results are shown in Table 2 below. The experimental examples in Table 2 are the cleanliness using the manufacturing method of the present invention, and the comparative examples in Table 2 are the cleanliness without the manufacturing method of the present invention.

As can be seen from Table 2, the cleanliness at the completion of the cold rolling step 21 and the annealing step 22 by the manufacturing method of the present invention is indeed superior to the cleanliness without the manufacturing method of the present invention. It can be seen that the manufacturing method of the present invention can improve the cleanliness of the cold-rolled product without electrolytic cleaning, thereby making the subsequent processing process easier, and also reducing the generation of defective products to reduce the production cost.

In summary, the method for manufacturing the cold-rolled product without electrolytic cleaning of the present invention utilizes the cation concentration, pH value, specific gravity and flow rate of the cleaning agent in the cold rolling step 21, and the annealing step 22 is used to control the annealing device 220. The gas flow rate and the treatment time can improve the cleanliness of the cold-rolled product without electrolytic cleaning, thereby making the subsequent processing process easier, and also reducing the production of defective products to reduce the production cost, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

200‧‧‧ steel embryo

201‧‧‧Semi-finished products

202‧‧‧Cold rolled products

21‧‧‧ cold rolling steps

211‧‧‧ cold rolling mill

212‧‧‧Cold rolls

22‧‧‧ Annealing step

220‧‧‧ Annealing equipment

221‧‧‧ initial annealing step

222‧‧ mid-anneal step

223‧‧‧End annealing step

23‧‧‧Quenching and rolling steps

231‧‧‧Single mill

24‧‧‧ Cold Rolling Finishing Step

241‧‧‧ leveling equipment

242‧‧‧ Cutting equipment

1 is a schematic view showing a method of manufacturing a cold-rolled steel coil; FIG. 2 is a flow chart showing a preferred embodiment of a method for manufacturing a cold-rolled product of the present invention; and FIG. 3 is a schematic view figure 1.

21‧‧‧ cold rolling step

22‧‧‧ Annealing step

221‧‧‧ initial annealing step

222‧‧ mid-anneal step

223‧‧‧End annealing step

23‧‧‧Quenching and rolling steps

24‧‧‧ Cold Rolling Finishing Step

Claims (4)

A method for manufacturing a cold-rolled product without electrolysis cleaning, comprising: a cold rolling step of cold rolling a hot-rolled steel blank into a semi-finished product of a predetermined volume size by using a plurality of tandem cold rolling mills, and Spraying the cleaning agent from the last cold rolling mill towards the semi-finished product, wherein the cleaning agent has a cation concentration of between 100 ppm and 300 ppm, a pH of between 3.0 and 7.0, a specific gravity of between 1.0 and 1.2, and a cleaning agent. The flow rate is between 5,000 liters per minute and 10,000 liters per minute; in an annealing step, the semi-finished product is annealed by controlling the gas flow rate and processing time in an annealing device, including an initial annealing step and a mid-annealing step. a step, and a final annealing step, the initial annealing step is between 3 hours and 6 hours, and the gas flow rate is between 8 cubic meters per hour and 15 cubic meters per hour, and the intermediate annealing The time of the second step is between 5 hours and 10 hours, and the gas flow rate is between 14 cubic meters per hour and 20 cubic meters per hour, and the time of the final annealing step is between 3 hours and 6 hours. Between the gas flow rate is 8 cubic meters per hour to 15 cubic meters per hour; a quenching and rolling step, using a plurality of adjustment rolls to press the semi-finished product to adjust the surface roughness of the semi-finished product And a cold rolling finishing step of flattening the semi-finished product by using a flattening device, and cutting the semi-finished product according to the set size with a cutting device. Cold-rolled products without electrolysis cleaning according to item 1 of the patent application scope a manufacturing method, wherein the cold rolling mill in the cold rolling step has a plurality of cold rolling rolls correspondingly arranged to roll the hot rolled steel preform, and the hot rolled steel blank is passed through the cold rolling mill The cold rolling rolls are rolled toward the annealing apparatus, and the cold rolling rolls of the cold rolling mill closest to the annealing apparatus are chrome-plated cold rolling rolls having a thickness of between 0.5 μm and 1.5 μm. The method for producing a cold-rolled product for electroless cleaning according to claim 1 or 2, wherein the cleaning agent in the cold rolling step is replaced every month. The method for manufacturing a cold-rolled product for electroless cleaning according to claim 1, wherein the annealing step is to control a flow rate of hydrogen in the annealing device.