Preparation process of corrosion-resistant cold-rolled steel

Abstract

The invention relates to a preparation process of corrosion-resistant cold-rolled steel, and belongs to the technical field of steel processing. The preparation technology of the corrosion-resistant cold-rolled steel comprises the steps that steel is subjected to acid pickling, corrosion inhibitor dipping, multiple times of annealing and multiple times of calendaring, and finally the steel is dipped with a corrosion inhibitor. A protection layer is formed on the surface of the steel through dipping of the corrosion inhibitor, pollution and oxidation are avoided, the corrosion inhibitor has high temperature resistance and thermal stability and is not prone to damage in the annealing process, the corrosion inhibitor is used for dipping in the cold rolling process and after cold rolling is completed, and therefore the effect of dual protection of the steel is achieved. The steel prepared through the steps has excellent corrosion resistance.

Description

Technical Field

[0001] The 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, thinner and higher precision cold-rolled strips and steel plates can be obtained, with high straightness, high surface finish, clean and bright surface of cold-rolled plates, and easy coating and plating processing. It is mainly used in automobiles, printed iron drums, construction, building materials, bicycles and other industries. It is also the best material for producing organic coated steel plates. The anti-corrosion process of cold-rolled steel strips on the market is still defective in implementation. When improving the anti-corrosion performance of cold-rolled steel strips, most of them are electroplated with corrosion-resistant alloy materials or directly brushed with anti-corrosion coatings on the cold-rolled steel strips. The anti-corrosion coatings are very easy to fall off due to external friction. In addition, when the cold-rolled steel strips are electroplated with corrosion-resistant alloy materials, the alloy materials are difficult to combine stably with the cold-rolled steel strips, therefore, the anti-corrosion performance of the cold-rolled steel strips will also be affected. Summary of the invention

[0003] The present invention relates to a preparation process of corrosion-resistant cold-rolled steel, and belongs to the technical field of steel processing. The preparation process of corrosion-resistant cold-rolled steel disclosed in the present invention includes the following steps: the steel is first pickled, impregnated with a corrosion inhibitor, annealed and rolled multiple times, and finally impregnated with a corrosion inhibitor. Through the impregnation of the corrosion inhibitor, a protective layer is formed on the surface of the steel to avoid contamination and oxidation, and the corrosion inhibitor has high temperature resistance and thermal stability, and is not easily destroyed 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 purpose 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 corrosion-resistant cold-rolled steel comprising the following steps:

[0006] (1) The steel is washed with an acid solution, washed with water, then immersed in a corrosion inhibitor, and dried to obtain pretreated steel;

[0007] (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;

[0008] (3) Then rolling, followed by alternating the annealing step and rolling in step (2) twice, and finally impregnating the corrosion inhibitor again after the rolling is completed.

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

[0010] 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;

[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 a corrosion inhibitor.

[0012] Furthermore, in the 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 the heating and stirring are 50-60° C. and 2-3 h, respectively.

[0013] Furthermore, in 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.

[0014] Furthermore, in the step A1, the temperature and time for continuing heating and stirring 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.

[0015] Furthermore, 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 addition amount of potassium hydroxide solid accounts for 3-5%wt of the total mass of liquid a and concentrated sulfuric acid.

[0016] Furthermore, 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.

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

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

[0019] Furthermore, the calendering thicknesses in 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.

[0020] Furthermore, in the step (3), after the final rolling is completed, the corrosion inhibitor is immersed again for 2-10 seconds.

[0021] Beneficial effects of the present invention:

[0022] Through the impregnation of corrosion inhibitors, a protective layer is formed on the surface of the steel to prevent contamination and oxidation. The corrosion inhibitor is resistant to high temperatures and has thermal stability, and is not easily destroyed during annealing. The corrosion inhibitor is used for impregnation during the cold rolling process and after the cold rolling is completed, thereby playing a double role in protecting the steel. Therefore, the steel produced through the above steps has excellent corrosion resistance. DETAILED DESCRIPTION

[0023] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with embodiments.

[0024] The eicosanoid involved in the present invention is purchased from Jiangsu Pules Biotechnology Co., Ltd., CAS No.: 506-30-9.

[0025] Example 1

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

[0027] (1) The steel is washed with an acid solution, washed with water, 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 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;

[0029] (3) Then rolling, followed by alternating the annealing step and rolling in step (2) twice, and finally, after the rolling is completed, the corrosion inhibitor is immersed again for 3 seconds.

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

[0031] 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;

[0032] A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide, and stir for 15 minutes to obtain the corrosion inhibitor.

[0033] In the 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 the heating and stirring are 50° C. and 2 h, respectively.

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

[0035] The temperature and time for continued heating and stirring in step A1 are 80° C. and 1 h respectively, the reflux temperature is 130° C., and the cooling refers to cooling to 80° C.

[0036] In step A2, the mass ratio of liquid a to concentrated sulfuric acid is 1:1, the insulation temperature and time are 70° C. and 2 h respectively, the added 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 the step (1), the steel material is SK85 steel, the acidic solution is a hydrochloric acid solution with a mass fraction of 20%, and the immersion time is 5 seconds.

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

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

[0040] 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.

[0041] Example 2

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

[0043] (1) The steel is washed with an acid solution, washed with water, then immersed in a corrosion inhibitor, and dried to obtain pretreated steel;

[0044] (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;

[0045] (3) Then rolling, followed by alternating the annealing step and rolling in step (2) twice, and finally, after the rolling is completed, the corrosion inhibitor is immersed again for 3 seconds.

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

[0047] 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;

[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 minutes to obtain the corrosion inhibitor.

[0049] In the 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 55° C. and 2.5 h, respectively.

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

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

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

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

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

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

[0056] 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.

[0057] Example 3

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

[0059] (1) The steel is washed with an acid solution, washed with water, then immersed in a corrosion inhibitor, and dried to obtain pretreated steel;

[0060] (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;

[0061] (3) Then rolling, followed by alternating the annealing step and rolling in step (2) twice, and finally, after the rolling is completed, the corrosion inhibitor is immersed again for 3 seconds.

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

[0063] 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;

[0064] A2: Add concentrated sulfuric acid to liquid a, raise the temperature and keep it warm, then add solid potassium hydroxide, and stir for 15 minutes to obtain the corrosion inhibitor.

[0065] In the 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 the heating and stirring are 60° C. and 3 h, respectively.

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

[0067] The temperature and time for continued heating and stirring in step A1 are 90° C. and 2 h respectively, the reflux temperature is 150° C., and the cooling refers to cooling to 90° C.

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

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

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

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

[0072] 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.

[0073] Comparative Example 1

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

[0075] Comparative Example 2

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

[0077] Comparative Example 3

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

[0079] Comparative Example 4

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

[0081] Comparative Example 5

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

[0083] Comparative Example 6

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

[0085] (1) The steel is washed with an acid solution, washed with water, and dried to obtain pre-treated steel;

[0086] (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;

[0087] (3) Then calendering is performed, and then the annealing step and calendering in step (2) are repeated twice alternately, and finally the whole step is completed by calendering.

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

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

[0090] The temperature and time of cooling and heat preservation in step (2) are 525° C. and 9 h respectively, the cooling rate is 5° C. / min, and the cooling temperature is 75° C.

[0091] 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.

[0092] Comparative Example 7

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

[0094] (1) The steel is washed with an acid solution, washed with water, then immersed in a corrosion inhibitor, and dried to obtain pretreated steel;

[0095] (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;

[0096] (3) Then calendering is performed, and then the annealing step and calendering in step (2) are repeated twice alternately, and finally the whole step is completed by calendering.

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

[0098] 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;

[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 minutes to obtain the corrosion inhibitor.

[0100] In the 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 55° C. and 2.5 h, respectively.

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

[0102] The temperature and time for continued heating and stirring in step A1 are 85° C. and 1.5 h respectively, the reflux temperature is 140° C., and the cooling refers to cooling to 85° C.

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

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

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

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

[0107] 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.

[0108] Performance Testing

[0109] Anticorrosion test: The corrosion-resistant cold-rolled steel prepared in Examples 1-3 and Comparative Examples 1-7 was made into samples of the same specifications. The longer the time for the copper sulfate dripping liquid with pH = 4 to completely change from blue to black lasted, the better the corrosion resistance of the prepared film layer; after the sample was electrochemically treated, the corrosion current density shifted to the negative direction of the ordinate, indicating that the conversion film had a good corrosion protection effect on the steel plate, and the data of the corrosion current density were obtained by fitting the polarization curve. The test results are shown in Table 1.

[0110] Table 1 Test results

[0111] Sample Blackening duration <![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] From the data analysis of Table 1, it can be seen that the blackening time of Examples 1-3 is longer than that of Comparative Examples 1-7, among which Comparative Example 6 has the shortest blackening time, and Example 2 has the longest blackening time. The corrosion current density of Examples 1-3 is less than that of Comparative Examples 1-7, among which Example 2 has the smallest corrosion current density. In Comparative Example 1-2, 4-aminobenzoic acid or 4-aminobenzoic acid amide is removed, which reduces the stability of the corrosion inhibitor; the ratio of 4-aminobenzoic acid to 4-aminobenzoic acid amide in Comparative Example 3-4 exceeds the range of the embodiment, and its anticorrosion effect decreases; in Comparative Example 5, stearic acid is used as a fatty acid, and its chain length is shorter than that of arachidic acid, and its heat resistance is slightly worse than that of the embodiment; in Comparative Example 6, no corrosion inhibitor is used, and its anticorrosion effect decreases sharply; in Comparative Example 7, no corrosion inhibitor is impregnated after cold rolling, resulting in a decrease in the anticorrosion effect.

[0113] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A process for preparing 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 the corrosion inhibitor again after the rolling is completed.

2. A process for preparing corrosion-resistant cold-rolled steel according to claim 1, characterized in that: 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.

3. The process for preparing corrosion-resistant cold-rolled steel according to claim 2, characterized in that: In the 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.

4. The process for preparing corrosion-resistant cold-rolled steel according to claim 2, characterized in that: 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.

5. The process for preparing corrosion-resistant cold-rolled steel according to claim 2, 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.

6. The process for preparing corrosion-resistant cold-rolled steel according to claim 2, 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 addition amount of potassium hydroxide solid accounts for 3-5%wt of the total mass of liquid a and concentrated sulfuric acid.

7. The process for preparing 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.

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

9. The process for preparing 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.

10. The process for preparing 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.