Preparation process of a corrosion-resistant cold-rolled steel

Abstract

The present invention relates to a preparation process of corrosion-resistant cold-rolled steel, belonging to the technical field of steel processing. The steps included in the preparation process of the corrosion-resistant cold-rolled steel disclosed by the present invention are as follows: The steel is first pickled, impregnated with a corrosion inhibitor, annealed multiple times and rolled multiple times, and finally impregnated with a corrosion inhibitor again. Through the impregnation of the corrosion inhibitor, a protective layer is formed on the surface of the steel, avoiding contamination and oxidation. Moreover, the corrosion inhibitor has high temperature resistance and thermal stability and is not easily damaged during annealing. The corrosion inhibitor impregnation is used both during the cold rolling process and after the cold rolling is completed, thus playing a dual role in protecting the steel. Therefore, the steel obtained through the above steps has excellent corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel processing and relates to a preparation process of corrosion-resistant cold-rolled steel. Background Art

[0002] Cold-rolled steel has good properties. That is, through cold rolling, cold-rolled strip steel and steel plates with thinner thickness and higher precision can be obtained, with high flatness, high surface finish, the surface of the cold-rolled plate is clean and bright, easy to be coated and plated, and is mainly applied to industries such as automobiles, printed iron drums, construction, building materials, bicycles, etc. At the same time, it is also the best material for producing organic coated steel plates. At present, there are still defects in the implementation of the anti-corrosion process of cold-rolled steel strips. When improving the anti-corrosion performance of cold-rolled steel strips, it is mostly by electroplating corrosion-resistant alloy materials or directly brushing anti-corrosion coatings on the cold-rolled steel strips. However, the anti-corrosion coatings are extremely easy to fall off due to external friction. In addition, when electroplating corrosion-resistant alloy materials on cold-rolled steel strips, it is difficult for the alloy materials to stably combine with the cold-rolled steel strips. Therefore, it will also affect the anti-corrosion performance of cold-rolled steel strips. Summary of the Invention

[0003] The present invention relates to a preparation process of corrosion-resistant cold-rolled steel, belonging to the technical field of steel processing. The preparation process of the corrosion-resistant cold-rolled steel disclosed by the present invention includes the following steps: The steel is first pickled, impregnated with a corrosion inhibitor, annealed multiple times and rolled multiple times, and finally impregnated with a corrosion inhibitor again. Through the impregnation of the corrosion inhibitor, a protective layer is formed on the surface of the steel to avoid being contaminated and oxidized, and the corrosion inhibitor has high temperature resistance and thermal stability and is not easily damaged during annealing. The corrosion inhibitor is impregnated during the cold rolling process and after the cold rolling is completed, thereby playing a dual role in protecting the steel. Therefore, the steel obtained through the above steps has excellent corrosion resistance.

[0004] The object of the present invention can be achieved through the following technical solutions:

[0005] A preparation process of corrosion-resistant cold-rolled steel, the preparation process of the corrosion-resistant cold-rolled steel includes the following steps:

[0006] (1) The steel is washed with an acidic solution, rinsed with water, and then put into a corrosion inhibitor for impregnation, and dried to obtain pre-treated steel.

[0007] (2) The pre-treated steel is put into an annealing furnace, nitrogen is introduced at the same time, heated and then kept warm, and then cooled and kept warm, and taken out of the furnace after cooling.

[0008] (3) Then it is rolled, and then the annealing step and rolling in step (2) are alternately repeated twice. Finally, after the rolling is completed, it is impregnated with a corrosion inhibitor again.

[0009] Further, the preparation method of the corrosion inhibitor is as follows:

[0010] A1: Mix 4-aminophenol derivatives with dimethylformamide, heat and stir, then add fatty acid, continue to heat and stir, separate the generated water by reflux, then cool down, and use a rotary evaporator to remove dimethylformamide under reduced pressure to obtain liquid a;

[0011] A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide and stir to obtain the corrosion inhibitor.

[0012] Further, in step A1, the 4-aminophenol derivatives are composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 1:1, and the temperature and time of the heating and stirring are 50 - 60 °C and 2 - 3 h respectively.

[0013] Further, in step A1, the mass ratio of the 4-aminophenol derivatives, dimethylformamide and fatty acid is 1:2:1 - 1.2, and the fatty acid is arachidic acid.

[0014] Further, in step A1, the temperature and time of the continued heating and stirring are 80 - 90 °C and 1 - 2 h respectively, the temperature of the reflux is 130 - 150 °C, and the cooling means cooling down to 80 - 90 °C.

[0015] Further, in step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1 - 1.2, the temperature and time of the heat preservation are 70 - 80 °C and 2 - 3 h respectively, and the addition amount of the solid potassium hydroxide accounts for 3 - 5% wt of the total mass of liquid a and concentrated sulfuric acid.

[0016] Further, in step (1), the steel is SK85 steel, the acidic solution refers to a hydrochloric acid solution with a mass fraction of 20 - 30%, and the impregnation time is 5 - 10 s.

[0017] Further, in step (2), the flow rate of nitrogen is 8 - 10 m 3 / s, and the temperature and time of the heat preservation are 700 - 750 °C and 13 - 15 h respectively.

[0018] Further, in step (2), the temperature and time of the cooling and heat preservation are 500 - 550 °C and 8 - 10 h respectively, and the cooling temperature is 70 - 80 °C.

[0019] Further, in step (3), the rolling thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm in sequence, and the rolling pressure and temperature are 550 MPa and 500 °C respectively.

[0020] Further, in step (3), after the final rolling is completed, impregnate with the corrosion inhibitor again for 2 - 10 s.

[0021] Advantages of the present invention:

[0022] Through the impregnation of the corrosion inhibitor, a protective layer is formed on the surface of the steel, preventing it from being contaminated and oxidized. Moreover, the corrosion inhibitor has high temperature resistance and thermal stability and is not easily damaged during annealing. The corrosion inhibitor is used for impregnation both during the cold rolling process and after the cold rolling is completed, thus playing a dual role in protecting the steel. Therefore, the steel obtained through the above steps has excellent corrosion resistance. Detailed implementation manners

[0023] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with embodiments, details the specific implementation manners, structures, features, and their effects of the present invention as follows.

[0024] The arachidic acid involved in the present invention was purchased from Jiangsu Pulesi Biotechnology Co., Ltd., CAS No.: 506 - 30 - 9.

[0025] Embodiment 1

[0026] A preparation process of corrosion - resistant cold - rolled steel, the preparation process of the corrosion - resistant cold - rolled steel includes the following steps:

[0027] (1) The steel is washed with an acidic solution, rinsed with water, and then immersed in a corrosion inhibitor and dried to obtain pretreated steel.

[0028] (2) The pretreated steel is placed in an annealing furnace, nitrogen is introduced simultaneously, heated and then kept warm, and then cooled and kept warm, and finally taken out of the furnace after cooling.

[0029] (3) Then rolling is carried out, and then the annealing step and rolling in step (2) are alternately repeated twice. Finally, after the rolling is completed, it is immersed in the corrosion inhibitor again for 3 s.

[0030] The preparation method of the corrosion inhibitor is as follows:

[0031] A1: 4 - aminophenol derivatives are mixed with dimethylformamide, heated and stirred, then fatty acid is added, and heating and stirring are continued. The generated water is separated by reflux, and then the temperature is lowered, and dimethylformamide is removed by reduced pressure using a rotary evaporator to obtain liquid a.

[0032] A2: Concentrated sulfuric acid is added to liquid a, the temperature is raised and kept warm, and then potassium hydroxide solid is added. After stirring for 15 min, the corrosion inhibitor is obtained.

[0033] In step A1, the 4 - aminophenol derivatives are composed of 4 - aminobenzoic acid and 4 - aminobenzamide with a mass ratio of 1:1, and the temperature and time of the heating and stirring are 50°C and 2 h respectively.

[0034] In step A1, the mass ratio of 4-aminophenol derivative, dimethylformamide and fatty acid is 1:2:1, and the fatty acid is arachidic acid.

[0035] In step A1, the temperature and time for continuous heating and stirring are 80 °C and 1 h respectively, the reflux temperature is 130 °C, and the temperature reduction means reducing the temperature to 80 °C.

[0036] In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1, the temperature and time for heat preservation are 70 °C and 2 h respectively, the addition amount of potassium hydroxide solid accounts for 3% wt of the total mass of liquid a and concentrated sulfuric acid, and the concentration of concentrated sulfuric acid is 18.4 mol / L.

[0037] In step (1), the steel is SK85 steel, the acidic solution refers to a hydrochloric acid solution with a mass fraction of 20%, and the impregnation time is 5 s.

[0038] In step (2), the flow rate of nitrogen is 8 m 3 / s, the heating rate for temperature increase is 5 °C / min, and the temperature and time for heat preservation are 700 °C and 13 h respectively.

[0039] In step (2), the temperature and time for temperature reduction and heat preservation are 500 °C and 8 h respectively, the temperature reduction rate is 5 °C / min, and the cooling temperature is 70 °C.

[0040] In step (3), the rolling thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, and 1.2 mm in sequence, and the rolling pressure and temperature are 550 MPa and 500 °C respectively.

[0041] Example 2

[0042] A preparation process of corrosion-resistant cold-rolled steel, the preparation process of the corrosion-resistant cold-rolled steel includes the following steps:

[0043] (1) The steel is washed with an acidic solution, rinsed with water, then impregnated in an inhibitor, and dried to obtain pretreated steel.

[0044] (2) The pretreated steel is put into an annealing furnace, nitrogen is introduced simultaneously, heated and then heat-preserved, then cooled and heat-preserved, and taken out of the furnace after cooling.

[0045] (3) Then roll, and then alternately repeat the annealing step and rolling in step (2) twice. Finally, after rolling is completed, it is impregnated in the inhibitor again for 3 s.

[0046] The preparation method of the inhibitor is as follows:

[0047] A1: Mix 4-aminophenol derivatives with dimethylformamide, heat and stir, then add fatty acid, continue to heat and stir, reflux to separate out the generated water, then cool down, and use a rotary evaporator to reduce pressure to separate and remove dimethylformamide to obtain liquid a;

[0048] A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide, and stir for 15 min to obtain the corrosion inhibitor.

[0049] In step A1, the 4-aminophenol derivatives are composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 1:1, and the temperature and time of the heating and stirring are 55 °C and 2.5 h respectively.

[0050] In step A1, the mass ratio of the 4-aminophenol derivatives, dimethylformamide and fatty acid is 1:2:1.1, and the fatty acid is arachidic acid.

[0051] In step A1, the temperature and time of the continued heating and stirring are 85 °C and 1.5 h respectively, the temperature of the reflux is 140 °C, and the cooling refers to cooling down to 85 °C.

[0052] In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1.1, the temperature and time of the heat preservation are 75 °C and 2.5 h respectively, the addition amount of the solid potassium hydroxide accounts for 4% wt of the total mass of liquid a and concentrated sulfuric acid, and the concentration of the concentrated sulfuric acid is 18.4 mol / L.

[0053] In step (1), the steel is SK85 steel, the acidic solution refers to a hydrochloric acid solution with a mass fraction of 25%, and the impregnation time is 7 s.

[0054] In step (2), the flow rate of nitrogen is 9 m 3 / s, the heating rate for temperature increase is 5 °C / min, and the temperature and time of the heat preservation are 725 °C and 14 h respectively.

[0055] In step (2), the temperature and time of the cooling and heat preservation are 525 °C and 9 h respectively, the cooling rate is 5 °C / min, and the cooling temperature is 75 °C.

[0056] In step (3), the rolling thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm in sequence, and the rolling pressure and temperature are 550 MPa and 500 °C respectively.

[0057] Example 3

[0058] A preparation process of corrosion-resistant cold-rolled steel, the preparation process of the corrosion-resistant cold-rolled steel includes the following steps:

[0059] (1) The steel is washed with an acidic solution, rinsed with water, and then immersed in an inhibitor and dried to obtain pretreated steel.

[0060] (2) The pretreated steel is placed in an annealing furnace, and nitrogen is introduced simultaneously. After heating, it is kept at a constant temperature, then cooled while maintaining a certain temperature, and finally taken out of the furnace after cooling.

[0061] (3) Then it is rolled. Subsequently, the annealing step and rolling in step (2) are alternately repeated twice. Finally, after rolling is completed, it is immersed in the inhibitor again for 3 s.

[0062] The preparation method of the inhibitor is as follows:

[0063] A1: 4-aminophenol derivatives are mixed with dimethylformamide, heated and stirred, then fatty acid is added, and heating and stirring are continued. The generated water is separated by reflux. Subsequently, the temperature is lowered, and dimethylformamide is removed under reduced pressure using a rotary evaporator to obtain liquid a.

[0064] A2: Concentrated sulfuric acid is added to liquid a, the temperature is raised and kept constant, then potassium hydroxide solid is added, and after stirring for 15 min, the inhibitor is obtained.

[0065] In step A1, the 4-aminophenol derivatives are composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 1:1. The temperature and time of the heating and stirring are 60 °C and 3 h respectively.

[0066] In step A1, the mass ratio of the 4-aminophenol derivatives, dimethylformamide, and fatty acid is 1:2:1.2, and the fatty acid is arachidic acid.

[0067] In step A1, the temperature and time of the continued heating and stirring are 90 °C and 2 h respectively. The temperature of the reflux is 150 °C, and the temperature reduction refers to reducing the temperature to 90 °C.

[0068] In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1.2. The temperature and time of the constant temperature are 80 °C and 3 h respectively. The addition amount of the potassium hydroxide solid accounts for 5% wt of the total mass of liquid a and concentrated sulfuric acid.

[0069] In step (1), the steel is SK85 steel, the acidic solution is a hydrochloric acid solution with a mass fraction of 30%, the immersion time is 10 s, and the concentration of the concentrated sulfuric acid is 18.4 mol / L.

[0070] In step (2), the flow rate of nitrogen is 10 m 3 / s, the heating rate for temperature increase is 5 °C / min, and the temperature and time of the constant temperature are 750 °C and 15 h respectively.

[0071] In step (2), the temperature and time for cooling and heat preservation are 550 °C and 10 h respectively, the cooling rate is 5 °C / min, and the cooling temperature is 80 °C.

[0072] In step (3), the calendering thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, and 1.2 mm in sequence, and the calendering pressure and temperature are 550 MPa and 500 °C respectively.

[0073] Comparative Example 1

[0074] The difference from Example 2 is that 4-aminobenzoic acid in the preparation process of the corrosion inhibitor is replaced with 4-aminobenzamide of equal mass, and other conditions are the same as those in Example 2.

[0075] Comparative Example 2

[0076] The difference from Example 2 is that 4-aminobenzamide in the preparation process of the corrosion inhibitor is replaced with 4-aminobenzoic acid of equal mass, and other conditions are the same as those in Example 2.

[0077] Comparative Example 3

[0078] The difference from Example 2 is that the 4-aminophenol derivative is composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 2:1, and other conditions are the same as those in Example 2.

[0079] Comparative Example 4

[0080] The difference from Example 2 is that the 4-aminophenol derivative is composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 0.5:1, and other conditions are the same as those in Example 2.

[0081] Comparative Example 5

[0082] The difference from Example 2 is that arachidic acid in the preparation process of the corrosion inhibitor is replaced with stearic acid of equal mass, and other conditions are the same as those in Example 2.

[0083] Comparative Example 6

[0084] Based on Example 2, a preparation process of corrosion-resistant cold-rolled steel, the preparation process of the corrosion-resistant cold-rolled steel includes the following steps:

[0085] (1) The steel is washed with an acidic solution, rinsed with water, and dried to obtain pretreated steel.

[0086] (2) The pretreated steel is put into an annealing furnace, nitrogen is introduced simultaneously, heated and then heat-preserved, then cooled and heat-preserved, and taken out of the furnace after cooling.

[0087] (3) Then perform calendering, and subsequently repeat the annealing step and calendering in step (2) alternately twice. Finally, complete the whole step by calendering.

[0088] In step (1), the steel is SK85 steel, the acidic solution refers to a hydrochloric acid solution with a mass fraction of 25%, and the impregnation time is 7 s.

[0089] In step (2), the flow rate of nitrogen is 9 m 3 / s, the heating rate for temperature increase is 5 °C / min, and the insulation temperature and time are 725 °C and 14 h respectively.

[0090] In step (2), the temperature and time for cooling and insulation are 525 °C and 9 h respectively, the cooling rate is 5 °C / min, and the cooling temperature is 75 °C.

[0091] In step (3), the calendered thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, and 1.2 mm in sequence, and the calendering pressure and temperature are 550 MPa and 500 °C respectively.

[0092] Comparative Example 7

[0093] Based on Example 2, a preparation process of corrosion-resistant cold-rolled steel, the preparation process of the corrosion-resistant cold-rolled steel includes the following steps:

[0094] (1) Wash the steel with an acidic solution, wash it with water, then put it into an inhibitor for impregnation, and dry it to obtain pretreated steel.

[0095] (2) Put the pretreated steel into an annealing furnace, simultaneously introduce nitrogen, heat it and then keep it warm, then cool it and keep it warm, and take it out of the furnace after cooling.

[0096] (3) Then perform calendering, and subsequently repeat the annealing step and calendering in step (2) alternately twice. Finally, complete the whole step by calendering.

[0097] The preparation method of the inhibitor is as follows:

[0098] A1: Mix 4-aminophenol derivative and dimethylformamide, heat and stir, then add fatty acid, continue to heat and stir, separate out the generated water by reflux, then cool down, and use a rotary evaporator to remove dimethylformamide under reduced pressure to obtain liquid a.

[0099] A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide, and stir for 15 min to obtain the inhibitor.

[0100] In step A1, the 4-aminophenol derivative is composed of 4-aminobenzoic acid and 4-aminobenzamide with a mass ratio of 1:1. The temperature and time of the heating and stirring are 55°C and 2.5 h, respectively.

[0101] In step A1, the mass ratio of the 4-aminophenol derivative, dimethylformamide and fatty acid is 1:2:1.1, and the fatty acid is arachidic acid.

[0102] In step A1, the temperature and time of the continued heating and stirring are 85°C and 1.5 h, respectively. The reflux temperature is 140°C, and the temperature reduction refers to reducing the temperature to 85°C.

[0103] In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1.1. The temperature and time of the heat preservation are 75°C and 2.5 h, respectively. The addition amount of solid potassium hydroxide accounts for 4% wt of the total mass of liquid a and concentrated sulfuric acid.

[0104] In step (1), the steel is SK85 steel, the acidic solution refers to a hydrochloric acid solution with a mass fraction of 25%, and the impregnation time is 7 s.

[0105] In step (2), the flow rate of nitrogen is 9 m 3 / s, and the heating rate for temperature increase is 5°C / min. The temperature and time of the heat preservation are 725°C and 14 h, respectively.

[0106] In step (2), the temperature and time of the temperature reduction and heat preservation are 525°C and 9 h, respectively. The temperature reduction rate is 5°C / min, and the cooling temperature is 75°C.

[0107] In step (3), the rolling thicknesses are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, and 1.2 mm in sequence. The rolling pressure and temperature are 550 MPa and 500°C, respectively.

[0108] Performance Test

[0109] Anticorrosion Test: The corrosion-resistant cold-rolled steels prepared in Examples 1-3 and Comparative Examples 1-7 are made into specimens with the same specifications. The pH = 4 copper sulfate dropping solution is used on the surface of the specimens. The longer the time it takes for the color to change from blue to black completely, the better the corrosion resistance of the prepared film layer. After the specimens are electrochemically treated, the corrosion current density shifts towards the negative direction of the ordinate, indicating that the conversion film has a good corrosion protection effect on the steel plate. The corrosion current density data is obtained by fitting the polarization curve. The test results are shown in Table 1.

[0110] Table 1 Test Results

[0111] Specimen Blackening duration s <![CDATA[Corrosion current density A / cm 2 > Example 1 62 <![CDATA[9.612×10 -8 > Example 2 65 <![CDATA[9.142×10 -8 > Example 3 60 <![CDATA[9.342×10 -8 > Comparative Example 1 47 <![CDATA[5.317×10 -7 > Comparative Example 2 45 <![CDATA[5.267×10 -7 > Comparative Example 3 52 <![CDATA[5.038×10 -7 > Comparative Example 4 53 <![CDATA[5.028×10 -7 > Comparative Example 5 45 <![CDATA[5.269×10 -7 > Comparative Example 6 28 <![CDATA[2.379×10 -6 > Comparative Example 7 34 <![CDATA[9.582×10 -7 >

[0112] It can be obtained from the data analysis in Table 1 that the blackening duration of Examples 1-3 is longer than that of Comparative Examples 1-7. Among them, the blackening duration of Comparative Example 6 is the shortest, and that of Example 2 is the longest. The corrosion current density of Examples 1-3 is less than that of Comparative Examples 1-7. Among them, the corrosion current density of Example 2 is the smallest. Removing 4-aminobenzoic acid or 4-aminobenzamide in Comparative Examples 1-2 reduces the stability of the corrosion inhibitor; the ratio of 4-aminobenzoic acid to 4-aminobenzamide in Comparative Examples 3-4 exceeds the range of the examples, and its anti-corrosion effect decreases; stearic acid is used as the fatty acid in Comparative Example 5, and its chain length is shorter than that of arachidic acid, and its heat resistance is slightly worse than that of the examples; no corrosion inhibitor is used in Comparative Example 6, and its anti-corrosion effect drops sharply; the steel strip is not impregnated with the corrosion inhibitor after cold rolling in Comparative Example 7, resulting in a decrease in the anti-corrosion effect.

[0113] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the technical content disclosed above within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation process of corrosion-resistant cold-rolled steel, characterized in that, The preparation process of the corrosion-resistant cold-rolled steel comprises the following steps: (1) The steel is washed with an acid solution, washed with water, then immersed in a corrosion inhibitor, and dried to obtain pretreated steel; (2) The pretreated steel is placed in an annealing furnace, nitrogen is introduced at the same time, and the steel is heated and then kept warm, then cooled and kept warm, and then taken out of the furnace after cooling; (3) then rolling, followed by alternating the annealing step and rolling in step (2) twice, and finally impregnating with a corrosion inhibitor again after the rolling is completed; The preparation method of the corrosion inhibitor is as follows: A1: 4-aminophenol derivative and dimethylformamide are mixed, heated and stirred, and then fatty acid is added, and the heating and stirring are continued. The generated water is separated by reflux, and then the temperature is lowered, and the dimethylformamide is separated and removed by a rotary evaporator under reduced pressure to obtain liquid a; A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide and stir to obtain a corrosion inhibitor; In step A1, the 4-aminophenol derivative is composed of 4-aminobenzoic acid and 4-aminobenzamide in a mass ratio of 1:1, and the temperature and time of heating and stirring are 50-60° C. and 2-3 h respectively; In the step A1, the mass ratio of the 4-aminophenol derivative, dimethylformamide and fatty acid is 1:2:1-1.2, wherein the fatty acid is arachidic acid.

2. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, The temperature and time for continued heating and stirring in step A1 are 80-90°C and 1-2h respectively, the reflux temperature is 130-150°C, and the cooling refers to cooling to 80-90°C.

3. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1-1.2, the insulation temperature and time are 70-80° C. and 2-3 h, respectively, and the added amount of potassium hydroxide solid accounts for 3-5%wt of the total mass of liquid a and concentrated sulfuric acid.

4. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, In the step (1), the steel material is SK85 steel, the acidic solution is a hydrochloric acid solution with a mass fraction of 20-30%, and the immersion time is 5-10s.

5. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, The flow rate of nitrogen in step (2) is 8-10 m 3 / s, and the temperature and time for heat preservation are 700-750 °C and 13-15 h respectively.

6. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, The temperature and time of cooling and heat preservation in the step (2) are 500-550°C and 8-10h respectively, and the cooling temperature is 70-80°C.

7. The preparation process of a corrosion-resistant cold-rolled steel according to claim 1, characterized in that, The calendering thicknesses in the step (3) are 2.2 mm, 2 mm, 1.8 mm, 1.6 mm, 1.4 mm, and 1.2 mm, respectively, and the calendering pressure and temperature are 550 MPa and 500° C., respectively.