CN110923600A

CN110923600A - Steel plate with zinc-manganese-magnesium-silicon alloy hot-dip coating and production method thereof

Info

Publication number: CN110923600A
Application number: CN201911250663.8A
Authority: CN
Inventors: 黄鸿途; 黄谊桢; 黄谊轩
Original assignee: JINJIANG ANNENG BUILDING MATERIALS MANUFACTURING Co Ltd
Current assignee: JINJIANG ANNENG BUILDING MATERIALS MANUFACTURING Co Ltd
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2020-03-27
Anticipated expiration: 2039-12-09
Also published as: CN110923600B

Abstract

The invention discloses a steel plate with a zinc-manganese-magnesium-silicon alloy hot-dip coating and a production method thereof, wherein the steel plate with the zinc-manganese-magnesium-silicon alloy hot-dip coating comprises a steel plate body and the zinc-manganese-magnesium-silicon alloy hot-dip coating; the zinc-manganese-magnesium-silicon alloy hot-dip coating covers the surface of the steel plate body; the zinc-manganese-magnesium-silicon alloy hot dip coating comprises the following components in parts by weight based on 100 parts of the whole coating: 90 to 96 parts of zinc, 1.0 to 5.0 parts of manganese, 0.5 to 1.2 parts of magnesium, 0.1 to 0.6 part of silicon, 0.025 to 0.145 part of vanadium and 0.008 to 0.105 part of ruthenium, and the balance of unavoidable impurities. The coating of the steel plate with the zinc-manganese-magnesium-silicon alloy hot-dip coating has the advantages that under the condition of the same coating thickness, the corrosion resistance of the traditional pure zinc coating is greatly improved, the corrosion resistance is improved by multiple times, the heavy corrosion resistance requirement can be met, the requirement on bridge steel wires in a marine corrosion atmosphere environment is met, and the market prospect is wide. In addition, the obtained plating layer has a flat and smooth surface.

Description

Steel plate with zinc-manganese-magnesium-silicon alloy hot-dip coating and production method thereof

Technical Field

The invention relates to the field of steel plates, in particular to a steel plate with a zinc-manganese-magnesium-silicon alloy hot-dip coating and a production method thereof.

Background

Any type of metal component made of ferrous material, more particularly of steel, generally has applications requiring it to receive effective protection against corrosion. In this respect, it is known practice to protect steel-based components from corrosion by galvanization (zinc coating). In galvanization, steel has a generally thin zinc coating to protect the steel from corrosion. There are various galvanizing processes available for galvanizing steel parts, in other words, coating them with a metallic covering of zinc, including in particular hot dip galvanizing, zinc metal spraying (wire flame spraying), diffusion galvanizing (galvannealing), electrogalvanizing (electrolytic galvanizing), electroless galvanizing by means of zinc foil coating, and mechanical galvanizing.

The most important method for corrosion protection of steel by means of metallic zinc coatings is probably hot dip galvanization. In this process, the steel is immersed continuously (e.g., coil and wire) or one by one (e.g., part) in a heating bath containing liquid zinc at a temperature of about 450 ℃ to 600 ℃ (the melting point of zinc is 419.5 ℃), so that a resistant alloy layer of iron and zinc is formed on the steel surface, and a very strongly adherent pure zinc layer is formed thereon.

Hot dip galvanization provides both active and passive corrosion protection. Passive protection is through the barrier effect of the zinc coating. Active corrosion protection is based on the cathodic activity of the zinc coating. Zinc acts as a sacrificial anode to protect the underlying iron from corrosion relative to the more noble metal (e.g., iron) in the electrochemical voltage series until the zinc itself is completely corroded.

According to DINENISO1461, individual galvanization is used for the hot dip galvanization of generally relatively large steel components and structures. Thus, the steel base blank or finished workpiece (part) is pretreated and subsequently immersed in a zinc melt bath. In particular, immersion allows easy access to interior surfaces, welds, and inaccessible locations on a part or workpiece for galvanizing.

Conventional hot dip galvanization is based in particular on dipping iron and/or steel components into a zinc melt to form a zinc coating or zinc covering on the surface of the component. In order to ensure the adhesion, impermeability and uniformity of the zinc coating, it is generally necessary to carry out in advance a thorough surface treatment of the part to be galvanized, generally comprising degreasing and subsequent rinsing operations, subsequent acid pickling and downstream rinsing operations, and finally flux treatment (i.e. so-called fluxing) and subsequent drying operations.

A typical process sequence for conventional galvanization by hot dip galvanization generally takes the form: in the case of galvanising identical or similar components one by one (for example, large-scale/high-volume or mass-production of automotive components), they are usually organized or grouped for the entire process for reasons of process economy and economy (in particular by means of a common goods carrier (article carrier), for example configured as a cross-beam or rack, or a common mounting or connecting device for a plurality of these identical or similar components). For this purpose, a plurality of components are connected to the goods carrier by means of holding devices (e.g. latching devices, binding wires, etc.). The grouped state components are then provided to subsequent processing steps or stages by the cargo carrier.

First, the surfaces of the grouped components are degreased to remove grease and oil residues, using a degreaser in the form of an alkaline or acidic degreaser, usually aqueous. Cleaning in a degreasing bath is usually followed by a rinsing operation, usually by immersion in a water bath, to prevent the degreasing agent from entraining the galvanized material into the subsequent pickling operation, which is particularly important in the case of the transition from alkaline degreasing to pickling.

The next step is an acid cleaning treatment (pickling), which is used in particular to remove homologous impurities (such as rust and scale) from the steel surface. Pickling is usually done in dilute hydrochloric acid, and the duration of the pickling procedure depends on factors including the contamination status (e.g. degree of rusting) of the galvanized material and the acid concentration and temperature of the pickling bath. In order to prevent or minimize the entrainment of the galvanized material by the residual acid and/or residual salt, a rinsing operation (rinsing step) is usually performed after the pickling treatment.

This is followed by so-called fluxing (treatment with flux), in which the previously degreased and pickled steel surface has a so-called flux therein, usually an aqueous solution containing inorganic chlorides, most commonly a mixture of zinc chloride (ZnCl) and ammonium chloride (NHCl). On the one hand, the flux is used for the final intensive fine cleaning of the steel surface before it reacts with the molten zinc, dissolving the scale on the zinc surface and preventing the steel surface from re-oxidation before the galvanization process. On the other hand, the flux improves the wetting ability between the steel surface and the molten zinc. A drying operation is usually carried out after the flux treatment to produce a solid film of flux on the steel surface and to remove adhering water, thereby avoiding subsequent unwanted reactions (especially the formation of steam) in the liquid zinc impregnation bath.

The parts pretreated in the manner described above are then dipped into a liquid zinc melt for hot dip galvanising. In the case of hot dip galvanization using pure zinc, the zinc content of the melt is at least 98.0 wt.% according to DIN EN ISO 1461. After the galvanized material is immersed in the molten zinc, it is left in the zinc melt bath for a sufficiently long time, in particular until the galvanized material has been at its temperature and coated with a zinc layer. Before the galvanized material is extracted again from the zinc melt, the surface of the zinc melt is generally cleaned to remove, inter alia, oxides, zinc dust, flux residues, etc. The hot dip galvanized component in this way is subsequently cooled (for example in air or in a water bath). Finally, the holding means for the component, such as the latching means, the binding or the like, are removed. After the galvanizing operation, a rework or post-treatment operation (which may be involved in some cases) is typically performed. In this operation, the excess zinc residues, in particular called the zinc droplet stream that solidifies on the edges, and the oxides or ashes that adhere to the parts, are removed as far as possible.

One criterion for the quality of hot dip galvanization is the thickness of the zinc coating in μm (micrometers). The DIN EN ISO1461 standard specifies the minimum value of the required coating thickness which is provided in terms of material thickness when galvanising one by one. In practice, the coating thickness is much higher than the minimum coating thickness specified in DINEN ISO 1461. Generally, the thickness of the zinc coating produced by the one-by-one galvanizing is 2-200 um micrometers or even more.

However, the hot-dip coated steel sheet currently used has the following problems:

1. the corrosion resistance is general, and the requirements of heavy corrosion resistance cannot be met;

2. the bonding strength of the plating layer and the substrate is low;

3. the combination properties such as appearance, strength and the like are poor.

Disclosure of Invention

In view of the above, it is an object of the present invention to provide a steel sheet having a hot-dip coating layer of a zinc-manganese-magnesium-silicon alloy and a method for producing the same, which can effectively solve the above problems.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a steel plate with a zinc-manganese-magnesium-silicon alloy hot dip coating comprises a steel plate body and the zinc-manganese-magnesium-silicon alloy hot dip coating; the zinc-manganese-magnesium-silicon alloy hot-dip coating covers the surface of the steel plate body; the zinc-manganese-magnesium-silicon alloy hot dip coating comprises the following components in parts by weight based on 100 parts of the whole coating:

90 to 96 parts of zinc, 1.0 to 5.0 parts of manganese, 0.5 to 1.2 parts of magnesium, 0.1 to 0.6 part of silicon, 0.025 to 0.145 part of vanadium and 0.008 to 0.105 part of ruthenium, and the balance of unavoidable impurities.

Preferably, the hot dip coating of the zinc-manganese-magnesium-silicon alloy comprises the following components in parts by weight based on 100 parts by weight of the whole coating:

91.5 to 95 parts of zinc, 2.3 to 4.2 parts of manganese, 0.7 to 1.1 parts of magnesium, 0.25 to 0.55 part of silicon, 0.075 to 0.125 part of vanadium and 0.065 to 0.100 part of ruthenium, and the balance of unavoidable impurities.

92.5 parts of zinc, 3.6 parts of manganese, 0.88 part of magnesium, 0.47 part of silicon, 0.114 part of vanadium and 0.093 part of ruthenium, and the balance of the alloy comprises inevitable impurities.

Preferably, the steel plate body is made of carbon steel.

Preferably, the hot dip coating of the zinc-manganese-magnesium-silicon alloy further comprises the following components in parts by weight based on 100 parts by weight of the whole coating:

0.003 to 0.125 part of cerium.

0.018-0.104 part of titanium.

The invention also provides a production method of the steel plate with the zinc-manganese-magnesium-silicon alloy hot dip coating, which comprises the following steps:

A. carrying out oil removal and rust removal treatment on the surface of the steel plate body;

B. hot dip coating the zinc-manganese-magnesium-silicon alloy hot dip coating at 515-535 ℃;

C. cooling the steel plate to 200 ℃ at an average cooling speed of 0.6-0.9 ℃/s after the hot dip coating is finished;

D. and annealing at 380-400 ℃ for 50-80 s to obtain the steel plate with the zinc-manganese-magnesium-silicon alloy hot dip coating.

Preferably, in the step B, the hot dip coating of the zinc-manganese-magnesium-silicon alloy is carried out at the temperature of 525 ℃.

Preferably, the thickness of the zinc-manganese-magnesium-silicon alloy hot-dip coating is 2-120 um.

Compared with the prior art, the invention has the following advantages and beneficial effects:

according to the steel plate with the zinc-manganese-magnesium-silicon alloy hot-dip coating, the raw material composition of the coating (the zinc-manganese-magnesium-silicon alloy hot-dip coating) is selected, the content of each raw material is optimized, and zinc, manganese, magnesium, silicon, vanadium, ruthenium and the like in proper proportion are selected, so that the advantages of the steel plate are fully exerted, the zinc, manganese, magnesium, silicon, vanadium, ruthenium and the like are supplemented with one another, the mutual promotion is realized, and the quality stability of products is improved. In addition, the obtained plating layer has a flat and smooth surface.

Manganese, magnesium, silicon, vanadium and ruthenium in proper proportion are added to the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy, the manganese, the magnesium, the silicon, the vanadium and the ruthenium are supplemented with one another, the mutual promotion is realized, the manganese, the silicon, the vanadium and the ruthenium are matched with other components, and a good synergistic effect is achieved, so that the corrosion resistance of the coating (the hot dip coating of the zinc-manganese-magnesium-silicon alloy) of the prepared steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy is greatly improved; particularly, manganese (can greatly improve the corrosion resistance of the hot dip coating of the zinc-manganese-magnesium-silicon alloy) and ruthenium (can obviously improve the long-term corrosion resistance of the hot dip coating of the zinc-manganese-magnesium-silicon alloy). In addition, the hot dip coating of the zinc-manganese-magnesium-silicon alloy is high in bonding strength and bonding tightness with a substrate.

Magnesium is added into the steel plate with the zinc-manganese-magnesium-silicon alloy hot dip coating in a proper proportion and is matched with other components, so that a good synergistic effect is achieved, and intergranular corrosion can be reduced; the alloy structure is refined, so that the strength of the alloy is increased; the wear resistance of the alloy is improved.

Cerium, titanium and the like in a proper proportion in the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy are matched with other components to play a good synergistic effect, so that the corrosion resistance of the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy (the hot dip coating of the zinc-manganese-magnesium-silicon alloy) is further improved; and the surface size accuracy can be improved, and the surface smoothness and smoothness of the coating can be improved.

The production method has simple process and simple and convenient operation, and saves manpower and equipment cost.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in connection with specific examples, which should not be construed as limiting the present patent.

The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials, unless otherwise indicated, are conventionally obtained commercially or prepared by conventional methods.

Example 1:

Preferably, the steel plate body is made of carbon steel.

0.003 to 0.125 part of cerium.

0.018-0.104 part of titanium.

The embodiment also provides a production method of the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy, which comprises the following steps:

Example 2:

91.5 parts of zinc, 2.3 parts of manganese, 0.7 part of magnesium, 0.25 part of silicon, 0.075 part of vanadium and 0.065 part of ruthenium, wherein the balance comprises inevitable impurities.

In this embodiment, the steel plate body is made of carbon steel and has a thickness of 1 cm.

In this embodiment, the hot dip coating of the zn-mn-mg-si alloy further includes, based on 100 parts by weight of the whole composition:

0.003 part of cerium.

0.018 parts of titanium.

B. hot dip coating the zinc-manganese-magnesium-silicon alloy hot dip coating at 515 ℃;

C. cooling the steel plate to 200 ℃ at an average cooling speed of 0.9 ℃/s after the hot dip plating is finished;

D. and then annealing at 380 ℃ for 80s to obtain the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy.

In the embodiment, in the step B, the hot dip coating of the zinc-manganese-magnesium-silicon alloy is carried out at the temperature of 525 ℃.

In this embodiment, the thickness of the zinc-manganese-magnesium-silicon alloy hot-dip coating is 80 um.

Example 3:

95 parts of zinc, 4.2 parts of manganese, 1.1 parts of magnesium, 0.55 part of silicon, 0.125 part of vanadium and 0.100 part of ruthenium, and the balance of the components comprises inevitable impurities.

0.125 part of cerium.

0.104 part of titanium.

B. hot dip coating the zinc-manganese-magnesium-silicon alloy hot dip coating at 535 ℃;

C. cooling the steel plate to 200 ℃ at an average cooling speed of 0.6 ℃/s after the hot dip plating is finished;

D. and then annealing at 400 ℃ for 50s to obtain the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy.

Example 4:

0.108 part of cerium.

0.086 part of titanium.

B. hot dip coating the zinc-manganese-magnesium-silicon alloy hot dip coating at 525 ℃;

C. cooling the steel plate to 200 ℃ at an average cooling speed of 0.7 ℃/s after the hot dip plating is finished;

D. and then annealing at 390 ℃ for 70s to obtain the steel plate with the hot dip coating of the zinc-manganese-magnesium-silicon alloy.

Comparative example 1:

a hot-dip coated steel sheet comprises a steel sheet body and a hot-dip coating; the hot dip coating covers on the steel plate body surface, and the hot dip coating is pure zinc coating, and thickness is 80 um.

The hot dip coating production method thereof refers to the method of example 4.

Comparative example 2:

the difference from example 4 is that there is no silicon (replacement with manganese), and the rest is the same as example 4.

Comparative example 3:

the difference from example 4 is that there is no magnesium (instead of zinc), and the rest is the same as example 4.

Comparative example 4:

the difference from example 4 is that there is no silicon (zinc is substituted), and the other is the same as example 4.

Comparative example 5:

the difference from example 4 is that there is no vanadium (replaced by zinc), and the rest is the same as example 4.

Comparative example 6:

the difference from example 4 is that there is no ruthenium (replacing with zinc), and the rest is the same as example 4.

The steel sheets having a hot dip coating of a zn-mn-mg-si alloy obtained in examples 2 to 4 of the present invention and the hot dip coated steel sheet of comparative example 1 were subjected to performance tests, the test results being shown in table 1:

1. corrosion resistance:

the saline was sprayed on the test board for 120 hours or 240 hours based on the saline spray test method (JIS-Z-2371). Subsequently, the white rust-formed area was visually inspected, and evaluation was made based on the following evaluation criteria. Note that: in this corrosion resistance evaluation, the indication result of "3" or more for 120 hours means that the corrosion resistance reaches the level of the temporary rust inhibitive application requiring higher corrosion resistance; in the corrosion resistance evaluation, the indication result of "3" or more for 240 hours means that the corrosion resistance reaches a level of heavy corrosion resistance.

4: the percentage of white rust-forming areas is less than 3%;

3: the percentage of white rust formation areas is 3% or more and less than 10%;

2: the percentage of white rust formation areas is 10% or more and less than 30%; and

1: the percentage of white rust formation area is 30% or more.

TABLE 1

	Corrosion resistance of 120 hours	Corrosion resistance at 240 hours
			Example 2	4	4
Example 3	4	4
			Example 4	4	4
Comparative example 1	2	1
			Comparative example 2	3	2
Comparative example 3	4	3
			Comparative example 4	4	3
Comparative example 5	3	2
			Comparative example 6	3	1

As can be seen from the above table, the steel sheet having the hot dip coating of zn-mn-mg-si alloy according to the present invention has the following advantages: the coating (the zinc-manganese-magnesium-silicon alloy hot-dip coating) of the steel plate with the zinc-manganese-magnesium-silicon alloy hot-dip coating has the advantages that under the condition of the same coating thickness, the corrosion resistance of the traditional pure zinc coating is greatly improved, and the corrosion resistance is improved by times; in addition, the obtained plating layer has a flat and smooth surface.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.

Claims

1. The steel plate with the zinc-manganese-magnesium-silicon alloy hot dip coating is characterized by comprising a steel plate body and the zinc-manganese-magnesium-silicon alloy hot dip coating; the zinc-manganese-magnesium-silicon alloy hot-dip coating covers the surface of the steel plate body; the zinc-manganese-magnesium-silicon alloy hot dip coating comprises the following components in parts by weight based on 100 parts of the whole coating:

2. The steel sheet having a hot dip coating layer of zn-mn-mg-si alloy as claimed in claim 1, wherein the composition of the hot dip coating layer of zn-mn-mg-si alloy contains, based on 100 parts by weight in total:

3. The steel sheet having a hot dip coating layer of zn-mn-mg-si alloy as claimed in claim 1, wherein the composition of the hot dip coating layer of zn-mn-mg-si alloy contains, based on 100 parts by weight in total:

4. The steel sheet having the hot dip coating of zn-mn-mg-si alloy as claimed in claim 1, wherein the steel sheet body is of a carbon steel material.

5. The steel sheet having a hot dip coating layer of zn-mn-mg-si alloy as claimed in claim 1, wherein the composition of the hot dip coating layer of zn-mn-mg-si alloy further contains, based on 100 parts by weight in total:

0.003 to 0.125 part of cerium.

6. The steel sheet having a hot dip coating layer of zn-mn-mg-si alloy as claimed in claim 1 or 5, wherein the composition of the hot dip coating layer of zn-mn-mg-si alloy further contains, based on 100 parts by weight in total:

0.018-0.104 part of titanium.

7. A method of producing a steel sheet having a hot dip coating layer of Zn-Mn-Mg-Si alloy as defined in any one of claims 1 to 5, comprising the steps of:

8. The method for producing a steel sheet having a hot dip coating layer of zinc-manganese-magnesium-silicon alloy as set forth in claim 7, wherein in the step B, the hot dip coating layer of zinc-manganese-magnesium-silicon alloy is hot dip coated at 525 ℃.

9. The method for producing a steel sheet having a hot-dip coating layer of Zn-Mn-Mg-Si alloy as claimed in claim 7, wherein the thickness of the hot-dip coating layer of Zn-Mn-Mg-Si alloy is 2 to 120 μm.

10. A method for producing a steel sheet having a hot dip coating layer of zn-mn-mg-si alloy as set forth in claim 6, comprising the steps of:

E. carrying out oil removal and rust removal treatment on the surface of the steel plate body;

F. hot dip coating the zinc-manganese-magnesium-silicon alloy hot dip coating at 515-535 ℃;

G. cooling the steel plate to 200 ℃ at an average cooling speed of 0.6-0.9 ℃/s after the hot dip coating is finished;

and annealing at 380-400 ℃ for 50-80 s to obtain the steel plate with the zinc-manganese-magnesium-silicon alloy hot dip coating.