KR20240116478A - Zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, Mn and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La and Mn and a method for manufacturing the same, and belongs to the field of steel metallurgy production technology. The present invention provides a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn, and the chemical composition of the plating layer is 0.5% to 5% aluminum, 0.5% to 3.0% magnesium, and 0.05% vanadium depending on mass percentage. %~1%, cerium 0.01%~0.50%, lanthanum 0.01%~0.30%, Mn 0.025%~1.0%, the rest is zinc and inevitable impurities, of which Al/Mg is 1.0~1.5, vanadium + cerium + lanthanum The total amount is 0.03% to 1.0%. The zinc-aluminum-magnesium alloy plating layer steel material provided in the present invention not only met users' requirements for high corrosion resistance for steel materials, but also satisfied users' demands for excellent stamping formability or high-strength steel materials, especially in the home appliance and automobile fields. It is suitable and has excellent prospects for popularization and application.

Description

Zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, Mn and manufacturing method thereof

The present invention relates to a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La and Mn and a method for manufacturing the same, and belongs to the field of steel metallurgy production technology.

Zn-Al-Mg alloy plating layer attracted widespread attention overseas in the 1980s and became the research focus in the specialized field of hot-dip galvanized zinc and zinc alloy plating layer. According to domestic and foreign research results, under the same level of Zn and Al content in the plating layer, hot-dip galvanized Zn-Al-Mg alloy plating layer steel sheet with Mg added has better corrosion resistance and processing application performance (formability, weldability and paintability) of the material. It is excellent and can replace the current corresponding hot-dip galvanized zinc or zinc alloy galvanized steel sheets, and the market demand prospects are very broad.

Hot-dip galvanized Zn-Al-Mg alloy coated steel sheets were industrialized production and application by steel companies such as nippon steel, nisshin steel, and Thyssenkrupp in the early 21st century. Currently, the main application field is the construction industry, and it is gradually expanding to industries such as home appliances and automobile manufacturing. It is spreading. In China, the research on Zn-Al-Mg alloy plating layer is relatively late, and at present, only Boshan Steel, Shugang, Guqian Steel, Panzhihua Steel and other enterprises have launched hot-dip galvanized Zn-Al-Mg alloy plating layer steel sheets.

Conventional hot-dip galvanized Zn-Al-Mg alloy plated steel sheets are classified into “low aluminum” (WAl<5%), “medium aluminum” (5%≤WAl<13%), and “high aluminum” (47%≤WAl≤57%) ) can be divided into three types: Depending on the type of Zn-Al-Mg alloy plated steel sheet, the Al and Mg content in the plated layer is different, and the structure and quality performance of the plated layer are different, so the application fields are also different. Patent document CN105063532A discloses a highly corrosion-resistant single-plated zinc-aluminum-magnesium rare earth protective plating layer and manufacturing process for obtaining a zinc-aluminum-magnesium alloy plating layer on a metal surface using a single hot-dip plating method. The plating layer and the metal matrix each maintain their original performance, but have a metallurgical bonding interface of more than 99.9%, and at the same time, the structure of the plating layer is dense, the composition is stable, there is no leakage, and the corrosion resistance is excellent, and the salt spray corrosion reaches 2060h. . The alloy plating layer has better corrosion resistance than a regular hot-dip plating pure zinc layer, improving lifespan. This single plating process can be reused and industrially produced, and overcomes the difficulties of plating metal and zinc-aluminum-magnesium alloy solutions, the difficulty of forming an excellent bonding interface between the two, and the tendency for skip plating to occur. It can be widely applied to metal surfaces to prepare a zinc-aluminum-magnesium alloy plating solution with 5%-12% Al and 1%-6% Mg content, and the produced co-precipitation layer is Zn/Al/MgZn ₂ three-dimensional It forms co-crystals and various types of two-dimensional co-crystals, which is the main reason why the co-precipitation layer has high corrosion resistance. The high corrosion resistance single plating type zinc-aluminum-magnesium rare earth protective plating layer mentioned above used a heavy aluminum component system.

Patent document CN109402547A provides a hot-dip galvanized steel sheet with excellent corrosion resistance, including a substrate and an Al-Zn-Si-Mg plating layer plated on the substrate, and a method for manufacturing the same, and the chemical composition mass percentage of the plating layer is Al: 45% to 65. %, Si: 0.1% to 3%, Mg: 0.2% to 5%, Mn: 0.001% to 0.15%, Cr: 0.001% to 0.5%, the remainder is Zn and inevitable impurities. The manufacturing method includes (1) a steel sheet pretreatment step, (2) heat immersing the steel sheet in a plating tank with a temperature of 560 to 595°C, and (3) removing the steel sheet from the plating solution and cooling it step by step. The galvanized steel sheet has excellent corrosion resistance, has an excellent suppressing effect on the occurrence of white rust and the development of red rust, and is effective in preventing failure and spread of the treated film originating from the incision. The above-mentioned hot-dip galvanized steel sheet with excellent corrosion resistance was plated using a high aluminum component system.

It can be seen that the high corrosion resistance zinc-aluminum-magnesium steel sheet is mainly a zinc-aluminum-magnesium steel sheet of medium/high aluminum content. As the content of Al and Mg increases, the corrosion resistance of the plating layer increases, but at the same time, the forming performance and welding performance deteriorate. In home appliance and automotive applications, Zn-Al-Mg alloy plated steel sheets must have excellent formability to meet the stamping forming needs of users. Currently, Zn-Al-Mg alloy plated steel sheets with medium/high aluminum composition systems are not yet available to users. cannot meet the requirements. In the case of automobile plates, the higher the strength of high-strength steel, the more alloying elements are contained in the steel base, and the wettability of the plating solution and the steel base is poor, which seriously affects the use of zinc, aluminum, and magnesium in high-strength steel. Therefore, it is important to provide a Zn-Al-Mg alloy plated steel sheet that has both high formability and corrosion resistance.

The technical problem to be solved by the present invention is to provide a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn, which has both high formability and corrosion resistance, and a method for manufacturing the same.

The technical solution for achieving the purpose of the present invention is as follows.

One aspect of the present invention is to provide a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn, and the chemical composition of the plating layer is 0.5% to 5% aluminum and 0.5% magnesium depending on mass percentage. ~3.0%, vanadium 0.05~1.0%, cerium 0.01%~0.50%, lanthanum 0.01%~0.30%, manganese 0.025%~1.0%, other trace alloy elements ≤0.3%, the remainder is zinc and inevitable impurities, among which Al/Mg is 1.0 to 1.5, and the total amount of vanadium + cerium + lanthanum is 0.3 to 1.0%.

In addition, the chemical composition of the plating layer is 0.8% to 3.2% aluminum, 0.8% to 2.5% magnesium, 0.05% to 0.40% vanadium, 0.03% to 0.30% cerium, 0.02% to 0.20% lanthanum, and 0.10% to 1.0% manganese. Containing %; Al/Mg is 1 to 1.2; The total amount of vanadium + cerium + lanthanum is 0.10% to 0.35%; It is desirable to satisfy at least one of the following.

In addition, it is preferable that the total of the above inevitable impurities is ≤0.010%, of which lead ≤0.002%, antimony ≤0.002%, tin ≤0.002%, arsenic ≤0.002%, tellurium ≤0.002%, and cadmium ≤0.002%.

In addition, the weight of the plating layer is 30 to 400 g/m ² and is calculated according to both sides. Preferably, the weight of the plating layer is 150 to 320 g/m ² and is preferably calculated according to both sides.

In addition, the steel base of the steel material is preferably selected from at least one of IF steel, low carbon aluminum quenching steel, bake hardening steel, QP steel, DP steel, TRIP steel, and TWIP steel.

Another aspect of the present invention is to provide a method for manufacturing the zinc-aluminum-magnesium alloy plating layer steel, which includes the steps of degreasing and cleaning the steel base, continuous annealing, heat dipping, and air knife purge.

In addition, the continuous annealing process is calculated as a volume percentage and controlled to ≥3.5% hydrogen in the oven. Preferably, the continuous annealing process is calculated as a volume percentage and controlled to control the hydrogen in the oven to 4.0% to 8.0%.

In addition, the steel-based zinc pot entry temperature is controlled to 420℃~520℃, the plating solution temperature during the heat dipping process is controlled to 410℃~520℃, and the temperature difference between the zinc pot entry temperature and the plating solution temperature is controlled to ±10℃. It is desirable to do so.

In addition, by rapid cooling after plating, the temperature at which the steel strip reaches the upper steering roller is controlled to ≤260℃. Preferably, by rapid cooling after plating, the temperature at which the steel strip reaches the upper steering roller is controlled to 200℃~260℃. Control is desirable.

The zinc-aluminum-magnesium alloy plated layer steel material provided by the present invention uses a low aluminum component system, and can produce a Zn-Al-Mg alloy plated layer steel sheet with both high corrosion resistance and formability through control of the plated layer components. According to the inspection results, the zinc-aluminum-magnesium alloy plated layer steel material of the present invention has a time for red rust to occur over 600h and even 3200h under neutral salt spray test conditions, and no clear cracks are visible upon visual observation after bending at 0T. The time for red rust to occur under neutral salt spray test conditions is 500h or even 3000h or more, and the adhesion of the sprayed coating layer after spraying is excellent. The zinc-aluminum-magnesium alloy plating layer steel is particularly suitable for home appliances and automobile fields and has excellent prospects for popularization and application.

The present invention provides a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn, and the chemical composition of the plating layer is 0% to 5% aluminum, 0.5% to 3.0% magnesium, and 0.05% vanadium depending on mass percentage. %~1%, cerium 0.01%~0.50%, lanthanum 0.01%~0.30%, manganese 0.025%~1.0%, other trace alloy elements ≤0.3%, the rest are zinc and inevitable impurities; Among them, Al/Mg is 1.0 to 1.5, the total amount of vanadium + cerium + lanthanum is 0.3 to 1.0%, and the other trace alloy elements are boron, silicon, titanium, calcium, manganese, molybdenum, chromium, niobium, yttrium and bismuth. is selected from at least one of

In order to secure the corrosion resistance of Zn-Al-Mg alloy plating layer steel, the current field mainly uses a medium/high aluminum component system. However, as the Al and Mg content increases, the forming and welding performance of the steel significantly deteriorates, making it suitable for home appliances, It is difficult to meet stamping forming performance requirements in fields such as automobiles. In response to the above problem, the present invention optimizes the addition of Mg, Al content (content ratio) and other alloy elements in the plating layer to provide core points where V is heterogeneous during the plating layer formation process and refines and reduces the grain size of the plating layer to improve the plating layer's density. Under the condition of improved ductility, the corrosion resistance of the plating layer was improved, Ce and La increased the fluidity of the plating solution, reduced the surface tension of the plating solution, increased the permeability of the plating solution to the steel base, and improved the bonding effect between the plating layer and the steel base. improved. Mn strengthens the bonding action of the plating layer and the steel base (especially Mn-containing high-strength steel) to form a Mn-rich intermetallic compound, so that the plating layer obtains excellent plastic toughness and easy subsequent processing, providing users with high corrosion resistance and high formability. can meet the requirements. However, excessive contents of V, Ce, La, and Mn form an oxide shell on the surface of the alloy plating solution, increasing zinc slag and affecting the surface quality of the plating layer.

During the plating layer preparation process, process restrictions are necessary to ensure excellent surface quality and performance of the plating layer. The thickness of the plating layer must be controlled within a certain range considering the ability of the air knife and the fluidity of the plating solution. If the weight of the plating layer is too large and the pressure of the air knife is low, it is not easy to control the surface quality and thickness of the plating layer. If the flow rate of the air knife is limited and the fluidity of the plating solution is constant, the thickness of the plating layer cannot be controlled to be too thin. Since the wettability of the plating solution varies depending on the surface of the steel sheet, a plating layer with good adhesion can be formed only on steel sheets with good wettability, and the annealing atmosphere is intended to improve the excellent reducing properties of the steel base surface. In general, the higher the H ₂ content, the better, but H ₂ The higher the content, the higher the risk of explosion. The temperature of the plating solution must be in a molten state and have good fluidity. Adding V and Mn increases the temperature range of the plating solution, but if the temperature is too high, it is easy to oxidize and zinc slag increases. To ensure complete solidification of the plating layer, the temperature of the steel sheet must be lowered below the solidification point before the first steering roller. Since zinc, aluminum, and magnesium are easily oxidized, rapid cooling can improve surface quality.

Hereinafter, the method of the present invention will be described according to examples. Those skilled in the art should understand that the following examples are used only to illustrate the invention and should not be considered as limiting the scope of the invention. If specific techniques or conditions are not indicated in the examples, they are carried out according to the techniques or conditions described in the literature in the relevant field or according to the product description. If the manufacturer is not indicated on the reagents or instruments used, they are all commercially available products.

Example 1 Preparation of zinc-aluminum-magnesium alloy plating layer steel material of the present invention

The weight of the plating layer is 50g/m ² (both sides), and the main components of the plating layer are aluminum 0.8%, magnesium 0.6%, vanadium 0.10%, lanthanum 0.05%, cerium 0.15%, manganese 0.20%, lead 0.002%, antimony 0.001%, chromium 0.001%. It contains 0.001% cadmium and 0.001% tin, the remainder is zinc, and the steel base is DP steel.

Manufacturing method: includes the steps of degreasing cleaning, continuous annealing, heat soak, air knife purge, and cooling. Among these, degreasing cleaning involves cleaning the steel base thoroughly after degreasing treatment, and continuous annealing process is calculated as a volume percentage and placed in an oven. Hydrogen is controlled to 5.0%, the temperature of the steel sheet entering the zinc pot is 450℃, the plating solution temperature during the heat dipping process is 440℃, and the temperature at which the steel strip reaches the upper steering roller is controlled to 260℃ by rapid cooling after plating. do.

Test method:

Corrosion resistance: Neutral salt spray accelerated corrosion test is used. The test conditions and method are conducted in accordance with GB/T10125 2012 “Artificial atmosphere corrosion test salt spray test”. The test device is a salt spray corrosion test box, concentration 50g/L. , NaCl deionized aqueous solution at pH 6.5 was used as the corrosion medium, the test temperature was 35±2℃, the sample size was 75mm Sealed, the sample is placed at an angle of 15° to 25° to the vertical direction. Observe the time for red rust to appear on the surface of the test sample.

Formability: Bend the sample 0T (180° bend, center radius 0) to visually observe whether there are cracks, and test the occurrence time of red rust at the bent area under neutral salt spray test conditions. Neutral salt spray test conditions and methods are as per GB/ Carry out according to T101252012 “Artificial atmosphere corrosion test salt spray test”.

Paintability: After oil coating, the coated steel sheet is degreased, painted or printed, then spray-dried. Then, the degree of bonding between the spray coating layer and the steel sheet is tested using the grid method. If the coating layer is not peeled off, the adhesion is excellent.

Test results: The zinc-aluminum-magnesium alloy plating layer steel manufactured in this example had good surface quality and excellent corrosion resistance, formability, and paintability. The time for red rust to occur under the neutral salt spray test conditions is more than 70 hours, and no clear cracks were observed with the naked eye after bending at 0T. The time for red rust to occur at the bent area under the neutral salt spray test conditions is more than 600 hours, and after spraying, the time for red rust to occur is more than 70 hours. The adhesion of the coating layer is excellent and can meet user needs.

Example 2 Preparation of zinc-aluminum-magnesium alloy plating layer steel material of the present invention

The weight of the plating layer is 150g/m ² (both sides), and the main components of the plating layer are 1.5% aluminum, 1.5% magnesium, 0.15% vanadium, 0.10% lanthanum, 0.10% cerium, 0.15% manganese, 0.001% lead, 0.002% antimony, and 0.001% chromium. It contains 0.001% cadmium and 0.001% tin, the remainder is zinc, and the steel base is TWIP steel.

Manufacturing method: includes the steps of degreasing cleaning, continuous annealing, heat soak, air knife purge, and cooling. Among these, degreasing cleaning involves cleaning the steel base thoroughly after degreasing treatment, and continuous annealing process is calculated as a volume percentage and placed in an oven. Hydrogen is controlled to 6.0%, the temperature of the steel sheet entering the zinc pot is 470℃, the plating solution temperature during the heat dipping process is 460℃, and the temperature at which the steel strip reaches the upper steering roller is controlled to 200℃ by rapid cooling after plating. do.

The test method is the same as Example 1.

Test results: The zinc-aluminum-magnesium alloy plating layer steel manufactured in this example had good surface quality and excellent corrosion resistance, formability, and paintability. The time for red rust to occur under the neutral salt spray test conditions is over 1800 hours, and no clear cracks were observed with the naked eye after 0T bending. The time for red rust to occur at the bent area under the neutral salt spray test conditions is over 1700 hours, and the coating layer after spraying It has excellent adhesion and can meet the needs of users.

Example 3 Preparation of zinc-aluminum-magnesium alloy plating layer steel material of the present invention

The weight of the plating layer is 320g/m ² (both sides), and the main components of the plating layer are 3.2% aluminum, 2.5% magnesium, 0.10% vanadium, 0.15% lanthanum, 0.20% cerium, 0.05% manganese, 0.002% lead, 0.001% antimony, and 0.001% chromium. It contains 0.002% cadmium and 0.002% tin, the remainder is zinc, and the steel base is QP steel.

Manufacturing method: includes the steps of degreasing cleaning, continuous annealing, heat soak, air knife purge, and cooling. Among these, degreasing cleaning involves cleaning the steel base thoroughly after degreasing treatment, and continuous annealing process is calculated as a volume percentage and placed in an oven. Hydrogen is controlled to 4.5%, the temperature of the steel sheet entering the zinc pot is 510℃, the plating solution temperature during the heat dipping process is 500℃, and the temperature at which the steel strip reaches the upper steering roller is controlled to 200℃ by rapid cooling after plating. do.

The test method is the same as Example 1.

Test results: The zinc-aluminum-magnesium alloy plating layer steel manufactured in this example had good surface quality and excellent corrosion resistance, formability, and paintability. The time for red rust to occur under neutral salt spray test conditions is more than 3200 hours, and no clear cracks were observed with the naked eye after bending at 0T. The time for red rust to occur at the bent area under neutral salt spray test conditions is more than 3000 hours, and the coating layer after spraying It has excellent adhesion and can meet the needs of users.

Comparative example

The coating weight is 180g/m ² (both sides), the main components of the plating layer are aluminum 1.6%, magnesium 1.6%, lead 0.001%, antimony 0.001%, chromium 0.001%, cadmium 0.001%, tin 0.001%, the rest is zinc, and the steel base is QP steel.

Manufacturing method: includes the steps of degreasing cleaning, continuous annealing, heat soak, air knife purge, and cooling. Among these, degreasing cleaning involves cleaning the steel base thoroughly after degreasing treatment, and continuous annealing process is calculated as a volume percentage and placed in an oven. Hydrogen is controlled to 3.5%, the temperature of the steel sheet entering the zinc pot is 470℃, the plating solution temperature during the heat dipping process is 470℃, and the temperature at which the steel strip reaches the upper steering roller is controlled to 300℃ by rapid cooling after plating. do.

The test method is the same as Example 1.

Test results: The zinc-aluminum-magnesium alloy plated layer steel manufactured according to this comparative example had relatively poor surface quality, had bright spot defects, and was relatively poor in corrosion resistance, formability, and paintability. The time for red rust to occur under neutral salt spray test conditions was over 1,400 hours, and slight cracks were observed with the naked eye after bending at 0T, and the time for red rust to occur at the bent portion under neutral salt spray test conditions was over 1,100 hours.

It should be noted that specific features, structures, materials or features described herein may be combined in any suitable manner in one or more embodiments. Additionally, those skilled in the art may combine and combine the various embodiments and features of the various embodiments described herein unless there is a conflict.

Claims (10)

In the zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn,
The chemical composition of the plating layer is 0.5% to 5% aluminum, 0.5% to 3.0% magnesium, 0.05% to 1.0% vanadium, 0.01% to 0.50% cerium, 0.01% to 0.30% lanthanum, and 0.025% to 1.0% manganese, depending on mass percentage. , Other trace alloy elements ≤ 0.3%, the remainder is zinc and inevitable impurities, of which Al/Mg is 1.0 to 1.5, and the total amount of vanadium + cerium + lanthanum is 0.3% to 1.0%. V, Ce Zinc-aluminum-magnesium alloy plating layer steel containing , La, and Mn. According to paragraph 1,
The chemical composition of the plating layer is 0.8% to 3.2% aluminum, 0.8% to 2.5% magnesium, 0.05% to 0.40% vanadium, 0.03% to 0.30% cerium, 0.02% to 0.20% lanthanum, and 0.10% to 1.0% manganese. including; Al/Mg is 1 to 1.2; The total amount of vanadium + cerium + lanthanum is 0.10% to 0.35%; A zinc-aluminum-magnesium alloy plating layer steel material that satisfies at least one of the following. According to paragraph 1,
Zinc-aluminum, characterized in that the total of the above inevitable impurities is ≤ 0.010%, of which lead ≤ 0.002%, antimony ≤ 0.002%, tin ≤ 0.002%, arsenic ≤ 0.002%, tellurium ≤ 0.002%, and cadmium ≤ 0.002%. -Magnesium alloy plating layer steel. According to paragraph 1,
The weight of the plating layer is 30 to 400 g/m ² and calculated according to both sides. Preferably, the weight of the plating layer is 150 to 320 g/m ² and calculated according to both sides. Zinc-aluminum-magnesium alloy Plated layer steel. According to paragraph 1,
The steel base of the steel is selected from at least one of IF steel, low carbon aluminum quenching steel, bake hardening steel, QP steel, DP steel, TRIP steel, and TWIP steel. Zinc-aluminum-magnesium alloy plating layer steel. In the method of manufacturing a zinc-aluminum-magnesium alloy plating layer steel containing V, Ce, La, and Mn according to any one of claims 1 to 5,
A manufacturing method comprising the following steps: steel base degreasing cleaning, continuous annealing, heat soaking, and air knife purge. According to clause 6,
A manufacturing method characterized in that the continuous annealing process is calculated as a volume percentage and controlled to ≥3.5% hydrogen in the oven, and preferably, the continuous annealing process is calculated as a volume percentage and the hydrogen in the oven is controlled to 4.0% to 8.0%. According to clause 6,
The steel-based zinc pot entry temperature is controlled to 420℃~520℃, the plating solution temperature during the heat dipping process is controlled to 410℃~520℃, and the temperature difference between the zinc pot entry temperature and the plating solution temperature is controlled to ±10℃. Characterized manufacturing method. According to clause 6,
The temperature at which the steel strip reaches the upper steering roller is controlled to ≤260℃ by rapid cooling after plating, and preferably the temperature at which the steel strip reaches the upper steering roller is controlled to 200℃~260℃ by rapid cooling after plating. A manufacturing method characterized by: A zinc-aluminum-magnesium alloy plating layer steel material containing V, Ce, La, and Mn obtained according to the manufacturing method according to any one of claims 6 to 9.