Tin-plated steel plate having chromium-free surface and manufacturing method therefor

Abstract

Disclosed in the present invention is a tin-plated steel plate having a chromium-free surface, comprising a substrate and a tin coating plated on the surface of the substrate. The surface of the tin coating is provided with a passivation film. The passivation film contains the following effective elements: Ti in an amount of 0.4-6 mg / m2, Zr in an amount of 0.3-4 mg / m2, at least one of Mn, Zn, and Mo in a total amount of 1-8 mg / m2, and P in an amount of 0.5-5 mg / m2. Further disclosed in the present invention is a method for manufacturing the steel plate, comprising the following steps: electroplating tin on the surface of a substrate; subjecting the tin-plated steel plate to tin coating reflow alloying treatment; immersing the tin-plated steel plate in a cathode treatment solution for cathode treatment; and performing passivation treatment on the tin coating. A chromium-free passivation solution comprises a water-soluble salt of titanium, a water-soluble salt of zirconium, at least one of water-soluble salts of manganese, zinc and molybdenum, and a first inorganic phosphate salt.

Description

Surface chromium-free tin-plated steel sheet and method for manufacturing the same TECHNICAL FIELD

[0001] The present invention relates to a steel sheet and a method for manufacturing the same, and more particularly, to a tin-plated steel sheet and a method for manufacturing the same. BACKGROUND

[0002] The tin-plated steel sheet is widely used as a metal can packaging material in the fields of food, beverage, and chemical industry. The tin-plated steel sheet has good formability, strong corrosion resistance, and is easy to print and coat, and a metal can manufactured using the tin-plated steel sheet has the advantages of a beautiful appearance, high can body strength, and a long shelf life of a can content, and has been widely used for a long time.

[0003] The tin-plated steel sheet is a steel sheet on which a pure tin layer is plated on a surface of a thin steel sheet by an electroplating method, and then a tin-iron alloy layer is formed between the pure tin layer and a steel substrate through a tin layer reflowing (alloying) process. Also, in order to secure good use properties of the tin-plated steel sheet for packaging, a passivation process is required to be performed on the surface of the tin-plated steel sheet.

[0004] A conventional passivation method of the tin-plated steel sheet is a chromate passivation process, and generally, the tin-plated steel sheet is subjected to an electrolytic treatment as a cathode in a dichromate or chromic anhydride solution, and hexavalent chromium in the solution is reduced to trivalent chromium oxide or metallic chromium and deposited on the surface of the tin-plated steel sheet. Although the tin-plated steel sheet itself does not contain hexavalent chromium, the production process uses a highly toxic hexavalent chromate, and thus the environmental friendliness of the production process is poor. In order to realize green environmental protection in the production of the tin-plated steel sheet, the prior art:

[0005] Chinese patent literature with the publication number CN101010452A and the publication date of August 1, 2007, entitled "Surface-treated metal material, method for surface treatment thereof, and metal material coated with resin, can, and can lid" discloses a surface-treated metal material and a method for surface treatment thereof, which forms an inorganic treatment film layer containing at least one of Ti, Zr, and Al, and further containing O and F on a metal surface by a cathodic electrolysis technique, and then coats a silane coupling agent or a water-soluble organic compound containing a phenol on the surface of the inorganic film layer to form a composite surface treatment layer.

[0006] Chinese patent literature with the publication number CN103429795A and the publication date of December 4, 2013, entitled "Multi-stage pretreatment of tinplate before coating with paint" discloses a two-step method for the corrosion prevention pretreatment of tinplate, which includes anodically polarizing the tin-plated steel sheet in a solution containing at least one inert water-soluble salt, and then contacting the tin-plated steel sheet with a water-soluble inorganic salt containing Zr, Ti, Hf, and / or Si and an organic polymer. SUMMARY

[0007] It is an object of the present application to provide a surface-chromium-free tin-plated steel sheet which ensures good surface properties without chromium on the surface.

[0008] To achieve the above object, the present application provides a surface-chromium-free tin-plated steel sheet comprising a base plate and a tin-plated layer plated on the surface of the base plate, the surface of the tin-plated layer having a passivation film; the passivation film containing the following effective elements:

[0009] Ti at a content of 0.4 to 6 mg / m 2 ;

[0010] Zr at a content of 0.3 to 4 mg / m 2 ;

[0011] at least one of Mn, Zn, and Mo at a total content of 1 to 8 mg / m 2 ;

[0012] P at a content of 0.5 to 5 mg / m 2 .

[0013] Further, in the surface-chromium-free tin-plated steel sheet according to the present application, the contents of the effective elements in the passivation film are further:

[0014] Ti: 0.8 to 4 mg / m 2 ;

[0015] Zr: 0.5 to 3 mg / m 2 ;

[0016] at least one of Mn, Zn, and Mo at a total content of 3 to 6 mg / m 2 ;

[0017] P: 1 to 3 mg / m 2 .

[0018] Further, in the surface-chromium-free tin-plated steel sheet according to the present application, the total content of the effective elements in the passivation film is 3 to 16 mg / m 2 .

[0019] Further, in the surface-chromium-free tin-plated steel sheet according to the present application, the total content of the effective elements in the passivation film is 6 to 12 mg / m 2 .

[0020] In some embodiments, the content of Ti in the passivation film is 0.8 to 2 mg / m 2 or 5 to 6 mg / m 2 .

[0021] In some embodiments, the content of Zr in the passivation film is 1.1 to 1.6 mg / m2 or 0.3-0.5mg / m 2 .

[0022] In some embodiments, the content of P in the passivation film is 2.6-3.5mg / m 2 .

[0023] In some embodiments, the total content of Mn, Zn and Mo in the passivation film is 2-3.5mg / m 2 or 2.6-3.1mg / m 2 .

[0024] In some embodiments, the surface of the chromium-free surface tin-plated steel plate of the present application has a surface wetting tension of 35-40mN / m, for example, 35-38mN / m or 38-40mN / m. In this context, the testing method of the surface wetting tension of the chromium-free surface tin-plated steel plate is the testing method of the surface tension of the testing material (dynes method) in the standard GB / T 14216-2008 "Determination of Wetting Tension of Plastic Film and Sheet".

[0025] In some embodiments, the chromium-free surface tin-plated steel plate of the present application has an adhesion of grade 1 or grade 2. In this context, the adhesion test adopts the paint film adhesion test method specified in QB / T 2673-2006 "Coated Tin (or Chromium) Plated Steel Sheet".

[0026] In some embodiments, the chromium-free surface tin-plated steel plate of the present application has a corrosion resistance of grade 1 or grade 2. In this context, the corrosion resistance test adopts the corrosion resistance test method specified in QB / T 2673-2006 "Coated Tin (or Chromium) Plated Steel Sheet".

[0027] Another object of the present application is to provide a manufacturing method of a chromium-free surface tin-plated steel plate, which does not use the environment-harmful hexavalent chromium in the manufacturing process, and still obtains a tin-plated steel plate with excellent comprehensive surface performance and food contact safety.

[0028] In order to achieve the above-mentioned objects, the present application provides a manufacturing method of a chromium-free surface tin-plated steel plate, which comprises the steps of:

[0029] electroplating tin on the surface of the substrate;

[0030] performing tin-plated layer reflow alloying treatment on the tin-plated steel plate;

[0031] immersing the tin-plated steel plate into a cathode treatment liquid to perform cathode treatment;

[0032] Passivation treatment: uniformly coating a chromium-free passivation solution to the surface of the tin-plated steel sheet by means of immersion and / or spraying; then drying; wherein the chromium-free passivation solution contains: a water-soluble salt of titanium, a water-soluble salt of zirconium, at least one of a water-soluble salt of manganese, zinc and molybdenum, a first inorganic phosphate.

[0033] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet, the concentration of the water-soluble salt of titanium in the chromium-free passivation solution is 0.3-3 g / L in terms of Ti element content; the concentration of the water-soluble salt of zirconium is 0.2-2.5 g / L in terms of Zr element content; the total concentration of the water-soluble salts of manganese, zinc and molybdenum is 1-5 g / L in terms of total content of Mn, Zn and Mo elements; and the concentration of the first inorganic phosphate is 0.3-3 g / L in terms of P element content.

[0034] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet, the concentration of the water-soluble salt of titanium in the chromium-free passivation solution is 0.6-2 g / L in terms of Ti element content; the concentration of the water-soluble salt of zirconium is 0.5-1.5 g / L in terms of Zr element content; the total concentration of the water-soluble salts of manganese, zinc and molybdenum is 2-4 g / L in terms of total content of Mn, Zn and Mo elements; and the concentration of the first inorganic phosphate is 1-2 g / L in terms of P element content.

[0035] In some embodiments, the concentration of the water-soluble salt of titanium in the chromium-free passivation solution is 0.6-1.2 g / L or 2.5-3 g / L in terms of Ti element content. In some embodiments, the concentration of the water-soluble salt of zirconium in the chromium-free passivation solution is 0.8-1.2 g / L or 0.2-0.3 g / L in terms of Zr element content. In some embodiments, the total concentration of the water-soluble salts of manganese, zinc and molybdenum in the chromium-free passivation solution is 2-5 g / L or 1.5-2 g / L in terms of total content of Mn, Zn and Mo elements. In some embodiments, the concentration of the first inorganic phosphate in the chromium-free passivation solution is 0.3-3 g / L or 0.3-1.5 g / L in terms of P element content.

[0036] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the water-soluble salt of titanium is at least one selected from the group consisting of potassium fluotitanate, ammonium fluotitanate, potassium titanyl oxalate, and titanyl oxysulfate; the water-soluble salt of zirconium is at least one selected from the group consisting of potassium fluozirconate, ammonium fluozirconate, zirconium sulfate, and zirconium nitrate; the first inorganic phosphate is at least one selected from the group consisting of potassium dihydrogen phosphate, sodium dihydrogen phosphate, sodium hypophosphite, and sodium pyrophosphate; the water-soluble salt of manganese, when contained, is at least one selected from the group consisting of manganese dihydrogen phosphate, potassium permanganate, and manganese nitrate; the water-soluble salt of zinc, when contained, is at least one selected from the group consisting of zinc dihydrogen phosphate, zinc sulfate, and zinc nitrate; and the water-soluble salt of molybdenum, when contained, is at least one selected from the group consisting of potassium molybdate, sodium molybdate, and ammonium molybdate. In some embodiments, the water-soluble salt of titanium is at least one selected from the group consisting of potassium fluotitanate, ammonium fluotitanate, potassium titanyl oxalate, and titanyl oxysulfate; or ammonium fluotitanate, potassium titanyl oxalate, and titanyl oxysulfate. In some embodiments, the water-soluble salt of zirconium is at least one selected from the group consisting of ammonium fluozirconate and zirconium sulfate; or potassium fluozirconate and zirconium sulfate. In some embodiments, the first inorganic phosphate is at least one selected from the group consisting of sodium dihydrogen phosphate and sodium hypophosphite; or sodium dihydrogen phosphate and sodium pyrophosphate. In some embodiments, the water-soluble salt of manganese, when contained, is at least one selected from the group consisting of manganese nitrate and potassium permanganate; or manganese dihydrogen phosphate and potassium permanganate. In some embodiments, the water-soluble salt of zinc, when contained, is at least one selected from the group consisting of zinc dihydrogen phosphate; or zinc dihydrogen phosphate and zinc sulfate. In some embodiments, the water-soluble salt of molybdenum, when contained, is at least one selected from the group consisting of potassium molybdate and ammonium molybdate.

[0037] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the chromium-free passivation solution further contains a surface wetting agent. The surface wetting agent can be a polyhydric alcohol such as polyethylene glycol and / or propylene glycol.

[0038] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the total content of the surface wetting agent such as polyethylene glycol and / or propylene glycol is 0.5 to 5 g / L.

[0039] In some embodiments, the total content of the surface wetting agent such as polyethylene glycol and / or propylene glycol can be further controlled to be 2 to 4 g / L, such as 1 to 1.5 g / L or 1 to 2.5 g / L.

[0040] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the solvent of the chromium-free passivation solution is water.

[0041] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the pH of the chromium-free passivation solution is 2 to 6.

[0042] In some embodiments, the pH of the chromium-free passivation solution can be further controlled to be 3 to 4.5, 3.5 to 6, or 2 to 3.5.

[0043] In some more specific embodiments, phosphoric acid and sodium phosphate can be used to adjust the pH of the chromium-free passivation solution.

[0044] Further, in the method of manufacturing the surface chromium-free tin plated steel sheet according to the present application, the temperature of the chromium-free passivation solution is 20-50°C.

[0045] In some embodiments, the temperature of the chromium-free passivation solution can be further controlled to be 30-40°C, 25-50°C, 40-50°C, or 35-40°C.

[0046] Further, in the method of manufacturing the surface chromium-free tin plated steel sheet according to the present application, the time of the passivation treatment (i.e. the time of coating + drying) is controlled to be 0.5-10s.

[0047] In some embodiments, the time of the passivation treatment can be further controlled to be 2-6s, 0.5-2s, or 2-3s.

[0048] Further, in the method of manufacturing the surface chromium-free tin plated steel sheet according to the present application, the cathode treatment solution uses a second inorganic phosphate solution, such as sodium hydrogen phosphate solution, with a concentration of 5-30g / L. Herein, the cathode treatment solution is an aqueous solution of the second inorganic phosphate. Herein, the second inorganic phosphate is an alkali metal phosphate. In some embodiments, the alkali metal is selected from one or both of sodium and potassium. In some embodiments, the second inorganic phosphate is selected from one or both of sodium dihydrogen phosphate and sodium hydrogen phosphate. Herein, sodium hydrogen phosphate refers to sodium monohydrogen phosphate.

[0049] In some embodiments, the cathode treatment solution can further use a second inorganic phosphate solution, such as sodium hydrogen phosphate solution, with a concentration of 10-20g / L or 20-30g / L.

[0050] Further, in the method of manufacturing the surface chromium-free tin plated steel sheet according to the present application, the electric quantity of the cathode treatment is 0.5-5C / dm 2 , such as 3-5C / dm 2 , or 4-5C / dm 2 .

[0051] In some embodiments, the electric quantity of the cathode treatment can be further controlled to be 1-3C / dm 2 .

[0052] Further, in the method of manufacturing the surface chromium-free tin plated steel sheet according to the present application, the temperature of the cathode treatment solution is 25-55°C.

[0053] In some embodiments, the temperature of the cathode treatment solution can be further controlled to be 35-45°C, 25-35°C, or 25-30°C.

[0054] In some embodiments, the time for the cathodic treatment can be 0.1-2 seconds.

[0055] In some embodiments, the tin-plated steel sheet is immersed in the cathodic treatment solution to perform the cathodic treatment (the tin-plated steel sheet serves as a cathode). In some embodiments, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, when performing the drying, the combined drying is performed using one of the following: hot air blowing, additional induction heating, and radiation heating. In some embodiments, the hot air is dry hot air, and the temperature of the hot air is preferably 100-160°C.

[0056] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the tin plating on the surface of the substrate can be performed using a method commonly used in the art, such as an acid sulfate type tin plating process or an acid sulfonic acid salt type tin plating process. In some embodiments, the plating solution of the acid sulfate type tin plating process includes stannous sulfate. In some embodiments, the plating solution of the acid sulfonic acid salt type tin plating process includes one or more of methyl sulfonic acid tin and phenol sulfonic acid tin.

[0057] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the amount of tin plated on the surface of the substrate is 0.3-16 g / m 2 , further 0.3-2.8 g / m 2 , 2.8-16 g / m 2 , 2-4 g / m 2 , or 2-2.8 g / m 2 , or 2.8-4 g / m 2 . In some embodiments, the substrate is plated with tin on both sides.

[0058] Further, in the method for manufacturing the surface-chromium-free tin-plated steel sheet according to the present application, the tin plated layer of the tin-plated steel sheet can be subjected to a soft alloying treatment using a method commonly used in the art.

[0059] In some embodiments, in the soft alloying treatment, the tin-plated steel sheet is heated to 240-310°C. Further, the tin-plated steel sheet can be heated by resistance heating or induction heating.

[0060] In some embodiments, the time for the soft alloying treatment is 0.5-3 seconds.

[0061] Compared to the prior art, the surface-chromium-free tin-plated steel sheet and the method for manufacturing the same according to the present application have the following advantages and beneficial effects:

[0062] The surface-chromium-free tin-plated steel sheet according to the present application has good surface properties without chromium on the surface, and has good paint wettability while ensuring excellent paint adhesion.

[0063] The manufacturing method of the surface chromium-free tin-plated steel plate provided by the present application does not use the environment-harmful hexavalent chromium in the process, the surface treatment process is green and environmentally friendly, and the chromium-containing passivation solution can be replaced to realize green production of the tin-plated steel plate. DETAILED DESCRIPTION

[0064] The surface chromium-free tin-plated steel plate provided by the present application will be further explained and described below in combination with specific examples, however, the explanation and description do not constitute undue limitation on the technical solutions of the present application.

[0065] Examples 1-8 and Comparative Examples 1-2

[0066] The surface chromium-free tin-plated steel plates of Examples 1-8 provided by the present application are all prepared by the following steps:

[0067] (1) tin plating on the surface of the substrate: the tin plating is performed in a stannous sulfate, methyl sulfonic acid tin plating solution or phenol sulfonic acid tin plating solution, the steel plate is plated on both sides, and the weight of the single-side tin layer can be controlled to be between 0.3-16 g / m 2 .

[0068] In some specific embodiments, the single-side tin plating amount of Examples 1-8 is all 2.8 g / m 2 .

[0069] (2) softening and alloying treatment of the tin-plated steel plate: the strip steel is rapidly heated to between 240-310℃ (the melting point temperature of metallic tin is 232℃) by resistance heating or induction heating. By completely melting the metallic tin layer in a short time of 0.5-3 s, the tin and iron can be diffused and mutually dissolved to form a tin-iron alloy layer.

[0070] (3) cathodic treatment of the tin-plated steel plate by immersing the tin-plated steel plate into a cathodic treatment solution (the tin-plated steel plate as cathode), the cathodic treatment solution can use a sodium hydrogen phosphate solution with a concentration of 5-30 g / L, the cathodic treatment solution can be controlled to be between 25-55℃, the cathodic treatment electric quantity can be 0.5-5 C / dm 2 , and the cathodic treatment time is 0.1-2 s.

[0071] (4) passivation treatment: the temperature of the chromium-free passivation solution is controlled to be between 20-50℃, and the chromium-free passivation solution is uniformly coated on the surface of the tin-plated steel plate by immersion or spraying or a combination of immersion and spraying, then the excess passivation solution is removed by a pair of squeezing rollers, and then the coated chromium-free passivation solution is rapidly dried into a film by blowing hot air with a temperature of 100-160℃, combined with one of induction heating and radiation heating, and the passivation treatment time is 0.5-10 s. The composition of the chromium-free passivation solution is shown in Table 1-1 and Table 1-2.

[0072] Table 1-1 and Table 1-2 list the ingredient contents of the chromium-free passivation solution of Examples 1-8 described in the present application.

[0073] Table 1-1 (the balance is deionized water)

[0074] Table 1-2 (the balance is deionized water)

[0075] Table 2 lists the specific process parameters of the surface treatment process of Examples 1-8 of the present application.

[0076] Table 2.

[0077] Table 3 lists the effective element contents of the chromium-free surface of the tin-plated steel sheets of Examples 1-8 prepared by the above method.

[0078] Table 3.

[0079] Note: The effective element contents in the above Table 3 are measured by dissolving the chromium-free passivation film on the surface of a certain area of tin-plated sheet, and then determining the element contents in the solution obtained by dissolving the chromium-free passivation film composition by inductively coupled plasma emission spectroscopy (ICP) and converting them into the element contents on the surface of the tin-plated sheet.

[0080] In order to verify the surface performance of the chromium-free surface of the tin-plated steel sheets of Examples 1-8 described in the present application, samples of the chromium-free surface of the tin-plated steel sheets of Examples 1-8 and the comparative tin-plated steel sheets of Comparative Examples 1-2 were taken, and their surface performance was detected, and the detection results are listed in Table 5. It should be noted that the tin-plated steel sheets of Comparative Example 1 and Comparative Example 2 in the present application are passivated by conventional cathode electrolytic chromate (specifically sodium dichromate), and the tin-plating amount on one side is 2.8 g / m 2 . Among them, the chromium passivation amount of Comparative Example 1 is 3 mg / m 2 , and the chromium passivation amount of Comparative Example 2 is 5 mg / m 2 .

[0081] Surface wetting performance: The surface wetting tension of the chromium-free surface treated tin-plated steel sheet was tested by the method (dynes method) for testing the surface tension of the test material in GB / T 14216-2008 "Determination of Wetting Tension of Plastic Film and Sheet", and the higher the value, the better the wetting performance of the tin-plated steel sheet.

[0082] Paint film adhesion performance: The paint film adhesion performance of the chromium-free surface treated tin-plated steel sheet was evaluated by the paint film adhesion test method specified in QB / T 2673-2006 "Coated Tin (or Chromium) Plated Steel Sheet". The test sample is a painted tin-plated steel sheet, and the type of paint used is epoxy phenolic paint, and the dry weight of the paint film is 6-7 g / m2 .

[0083] Corrosion resistance performance: The test sample is a painted tinplate, and the test method for corrosion resistance is in accordance with QB / T 2673-2006 "Coated Tinplate (or Chromium) Steel Sheet". The corrosion resistance of the tinplate with chromium-free surface treatment is evaluated. The test sample is a painted tinplate, and the type of paint used is epoxy phenolic paint, and the dry weight of the paint film is 6-7 g / m 2 .

[0084] Table 4 lists the surface performance test results of the tinplate with chromium-free surface of examples 1-8 and the comparative steel of comparative examples 1-2.

[0085] Table 4.

[0086] As can be seen from the above table 4, the tinplate with chromium-free surface of examples 1-8 prepared by the manufacturing method of the present application has good surface performance, and the paint film adhesion performance and corrosion resistance performance are not obviously different from those of the conventional cathode electrolytic chromium-containing passivated tinplate, and the paint film adhesion is good; and the surface wetting tension is more excellent than that of the conventional cathode electrolytic chromium-containing passivated tinplate.

[0087] It should be noted that the above listed examples are only specific embodiments of the present application. Obviously, the present application is not limited to the above examples, and similar changes or modifications made in accordance with the disclosure of the present application are directly derived or easily thought of by those skilled in the art, and should all belong to the protection scope of the present application.

Claims

1. A chromium-free tin-plated steel sheet, comprising a substrate and a tin-plated layer coated on the surface of the substrate, wherein the surface of the tin-plated layer has a passivation film; characterized in that, The passivation film contains the following effective elements: Content is 0.4-6 mg / m³ 2 Ti; The content is 0.3-4 mg / m³. 2 Zr; Total content is 1-8 mg / m³ 2 At least one of Mn, Zn, and Mo; Content is 0.5-5 mg / m³ 2 P.

2. The chromium-free tin-plated steel sheet as described in claim 1, characterized in that, The content of each effective element in the passivation film is further as follows: Ti: 0.8-4mg / m 2 ; Zr:0.5-3mg / m 2 ; Total content is 3-6 mg / m³ 2 At least one of Mn, Zn, and Mo; P:1-3mg / m 2 .

3. The chromium-free tin-plated steel sheet as described in claim 1, characterized in that, The total content of the effective elements in the passivation film is 3-16 mg / m³. 2 Preferably 6-12 mg / m³ 2 .

4. The chromium-free tin-plated steel sheet as described in claim 1, characterized in that, The surface wetting tension of the chromium-free tin-plated steel sheet is 35-40 mN / m; and / or, the adhesion of the chromium-free tin-plated steel sheet is grade 1 or 2; and / or, the corrosion resistance of the chromium-free tin-plated steel sheet is grade 1 or 2.

5. The method for manufacturing a chromium-free tin-plated steel sheet as described in any one of claims 1-4, characterized in that... Including the following steps: Tin plating is performed on the substrate surface; The tin-plated steel sheet is subjected to a softening alloying treatment for the tin plating layer. The tin-plated steel sheet is immersed in a cathodic treatment solution for cathodic treatment. Passivation treatment: A chromium-free passivation solution is uniformly coated onto the surface of a tin-plated steel sheet by immersion and / or spraying; then dried; wherein the chromium-free passivation solution contains: at least one of a water-soluble salt of titanium, a water-soluble salt of zirconium, a water-soluble salt of manganese, zinc and molybdenum, and a first inorganic phosphate.

6. The manufacturing method as described in claim 5, characterized in that, In the chromium-free passivation solution, the concentration of the water-soluble salt of titanium, based on the Ti element content, is 0.3-3 g / L; the concentration of the water-soluble salt of zirconium, based on the Zr element content, is 0.2-2.5 g / L; the total concentration of the water-soluble salts of manganese, zinc, and molybdenum, based on the total Mn, Zn, and Mo element content, is 1-5 g / L; and the concentration of the first inorganic phosphate, based on the P element content, is 0.3-3 g / L. Preferably, the concentration of the water-soluble salt of titanium is 0.6-2 g / L; the concentration of the water-soluble salt of zirconium is 0.5-1.5 g / L; the concentration of the water-soluble salts of manganese, zinc, and molybdenum is 2-4 g / L; and the concentration of the first inorganic phosphate is 1-2 g / L.

7. The manufacturing method as described in claim 5, characterized in that, The water-soluble salt of titanium is selected from at least one of potassium fluorotitanate, ammonium fluorotitanate, potassium titanium oxalate, and titanium oxysulfate; the water-soluble salt of zirconium is selected from at least one of potassium fluorozirconate, ammonium fluorozirconate, zirconium sulfate, and zirconium nitrate; the first inorganic phosphate is selected from at least one of potassium dihydrogen phosphate, sodium dihydrogen phosphate, sodium hypophosphite, and sodium pyrophosphate; the water-soluble salt of manganese is selected from at least one of manganese dihydrogen phosphate, potassium permanganate, and manganese nitrate; the water-soluble salt of zinc is selected from at least one of zinc dihydrogen phosphate, zinc sulfate, and zinc nitrate; and the water-soluble salt of molybdenum is selected from at least one of potassium molybdate, sodium molybdate, and ammonium molybdate.

8. The manufacturing method as described in claim 5, characterized in that, The chromium-free passivation solution also contains a surface wetting agent, preferably polyethylene glycol and / or propylene glycol; preferably, the total content of the surface wetting agent, such as polyethylene glycol and / or propylene glycol, is 0.5-5 g / L.

9. The manufacturing method as described in claim 5, characterized in that, The pH value of the chromium-free passivation solution is 2-6; and / or the temperature of the chromium-free passivation solution is 20-50℃.

10. The manufacturing method as described in claim 5, characterized in that, The passivation treatment time is 0.5-10s.

11. The manufacturing method as described in claim 5, characterized in that, The cathode treatment solution before passivation uses a second inorganic phosphate solution with a concentration of 5-30 g / L, preferably a sodium hydrogen phosphate solution.

12. The manufacturing method as described in claim 5, characterized in that, The charge for cathode treatment is 0.5-5 C / dm. 2 ; and / or, the temperature of the cathode treatment solution is 25-55°C.

13. The manufacturing method as described in claim 5, characterized in that, During the drying process, a combination of hot air blowing and induction heating or radiation heating is used for drying.

14. A chromium-free passivation solution comprising: (1) a water-soluble salt of titanium, (2) a water-soluble salt of zirconium, (3) at least one of water-soluble salts of manganese, zinc, and molybdenum, (4) a first inorganic phosphate, and (5) an optional surface wetting agent such as polyethylene glycol and / or propylene glycol; preferably, the concentration of the water-soluble salt of titanium in the chromium-free passivation solution, based on the elemental content of Ti, is 0.3-3 g / L; and the concentration of the water-soluble salt of zirconium, based on the elemental content of Zr, is 0.2-2.5 g / L. L; the total concentration of the water-soluble salts of manganese, zinc and molybdenum, calculated based on the total content of Mn, Zn and Mo, is 1-5 g / L; the concentration of the first inorganic phosphate, calculated based on the content of P, is 0.3-3 g / L; preferably, the concentration of the water-soluble salt of titanium is 0.6-2 g / L; the concentration of the water-soluble salt of zirconium is 0.5-1.5 g / L; the concentration of the water-soluble salts of manganese, zinc and molybdenum is 2-4 g / L; and the concentration of the first inorganic phosphate is 1-2 g / L.

15. The chromium-free passivation solution as described in claim 14, characterized in that, The water-soluble salt of titanium is selected from at least one of potassium fluorotitanate, ammonium fluorotitanate, potassium titanium oxalate, and titanium oxysulfate; the water-soluble salt of zirconium is selected from at least one of potassium fluorozirconate, ammonium fluorozirconate, zirconium sulfate, and zirconium nitrate; the first inorganic phosphate is selected from at least one of potassium dihydrogen phosphate, sodium dihydrogen phosphate, sodium hypophosphite, and sodium pyrophosphate; the water-soluble salt of manganese is selected from at least one of manganese dihydrogen phosphate, potassium permanganate, and manganese nitrate; the water-soluble salt of zinc is selected from at least one of zinc dihydrogen phosphate, zinc sulfate, and zinc nitrate; the water-soluble salt of molybdenum is selected from at least one of potassium molybdate, sodium molybdate, and ammonium molybdate; and / or, the pH of the chromium-free passivation solution is 2-6. 。

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