Copper-containing antibacterial steel and method for producing the same

Abstract

The application discloses a kind of copper-containing antibacterial steel and preparation method thereof, belong to antibacterial steel preparation technical field, solve the technical problems such as long construction period and non-environmental protection of antibacterial steel prepared by traditional aging method.The preparation method of the copper-containing antibacterial steel disclosed in the application utilizes the characteristic of copper brittleness, heats the steel plate or ingot to the melting point of copper, and then performs hot deformation such as forging or rolling, rapidly cools the surface, rapidly cools the melted copper and adheres to the surface of the material.The material prepared by this method is different from traditional antibacterial steel.The preparation of traditional antibacterial steel utilizes the means of precipitation, and the nanoscale precipitated copper is dispersedly distributed in the matrix.The copper-containing antibacterial steel prepared by this method has a layer of pure copper on its surface, and the final product is similar to the product prepared by electroplating or chemical plating, etc., and is environmentally friendly and pollution-free.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of antibacterial steel preparation, and particularly relates to a copper-containing antibacterial steel and a preparation method thereof. BACKGROUND

[0002] Antibacterial steel refers to steel material with bactericidal and anti-microbial corrosion ability, which is currently used in many microbial corrosion-prone scenarios such as pipeline transportation and offshore equipment. The principle is to dissolve some naturally bactericidal elements into steel to make the steel have the ability to resist microbial corrosion. These elements include silver, copper, titanium, etc. Considering the cost, antibacterial performance and the influence of antibacterial elements on the mechanical properties of steel, copper is the most widely used antibacterial steel additive element. However, the material obtained by simply smelting copper with steel does not have antibacterial properties and needs to be properly heat treated to have antibacterial properties. The reason is that the copper dissolved in the steel cannot be released, so it does not have bactericidal function and must be heat treated to form a copper-rich phase so that copper ions can be released, thus having bactericidal function. The antibacterial principle of antibacterial steel is shown in Figure 1 The copper atoms refer to those dissolved in the matrix, and the copper-rich phase atoms refer to those precipitated after heat treatment. For the copper-added antibacterial steel at present, copper is precipitated by aging to make it have antibacterial ability, but aging usually takes a long time, increases the process and wastes time. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a copper-containing antibacterial steel and a preparation method thereof, which solves the technical problems of long construction period and environmental pollution in the preparation of antibacterial steel by using the traditional aging method.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] The present application discloses a preparation method of a copper-containing antibacterial steel, comprising the following steps:

[0006] The copper-containing steel is placed in an oxidizing atmosphere and heated, and after heating, plastic deformation treatment is performed to obtain a copper-containing antibacterial steel with a copper layer on the surface;

[0007] The composition of the copper-containing steel includes copper, nickel, boron and other alloying elements; the mass percentage of copper is 2wt.%-4wt.%, the mass percentage ratio of nickel to copper is (1:2) to (1:3), the content of boron is 10ppm-20ppm, and the balance is other alloying elements.

[0008] Further, the heating is performed by a box-type furnace or an induction heating device.

[0009] Further, when the heating is performed by the box furnace, the temperature of the box furnace is set to 1100 DEG C to 1300 DEG C, and the heating time is set to 5 min to 8 min.

[0010] Further, when the heating is performed by the induction heating device, the heating power of the induction heating device is set to 70 Kwa, and the heating time is set to 3 s to 5 s.

[0011] Further, the oxidizing atmosphere is oxygen.

[0012] Further, the copper-containing steel material is heated in the oxidizing atmosphere until the temperature within 1 mm of the surface of the copper-containing steel material is greater than 1100 DEG C or above, and the temperature below 1 mm of the surface of the copper-containing steel material is lower than 1100 DEG C, and the heating is completed.

[0013] Further, the thickness of the copper layer on the surface of the copper-containing antibacterial steel is greater than 0 mm and less than 1 mm.

[0014] Further, the plastic deformation treatment is performed by forging or rolling.

[0015] Further, the copper-containing antibacterial steel with the surface having the copper layer is in the shape of a plate or a steel ingot.

[0016] The application further discloses the copper-containing antibacterial steel prepared by the preparation method.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] The application discloses a preparation method of copper-containing antibacterial steel, and the method utilizes the characteristic of copper brittleness, heats a steel plate or a steel ingot to the melting point of copper, and then performs hot deformation such as forging or rolling, so that the surface is rapidly cooled, and the melted copper is rapidly cooled and adhered to the surface of the material; the material prepared by the method is different from traditional antibacterial steel; the traditional antibacterial steel is prepared by using a separation means, and the nanometer copper is dispersedly distributed in the matrix; the copper-containing antibacterial steel prepared by the method has a pure copper layer on the surface, and the final product is similar to a product prepared by electroplating or chemical plating, and is environment-friendly and non-polluted.

[0019] Further, the copper-containing steel is heated to a target temperature of 1100-1300 DEG C in an oxidizing atmosphere, and the temperature of the steel within 1 mm of the surface is higher than 1100 DEG C; if the heating temperature is low, for example, 1100 DEG C, the heating can be kept for a long time; if the heating temperature is high, for example, 1300 DEG C, the heating rate and the heating temperature should be strictly controlled to ensure that the temperature of the surface below 1 mm is lower than 1100 DEG C, the liquid copper is prevented from being generated and corroding the grain boundary of the matrix, and the copper within 1 mm is prevented from being excessively separated out, so that a layer of red copper is finally produced on the surface, and the thickness of the copper is controlled to be within 1 mm. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of antibacterial stainless steel principle.

[0021] Figure 2 Schematic view of the heating by induction heating device followed by rolling; DETAILED DESCRIPTION

[0022] To enable persons skilled in the art to better understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used in the text are the usual meanings understood by those skilled in the art of the present application, and in the event of a conflict, the definition in the specification shall prevail.

[0023] Theories and mechanisms described and disclosed herein, whether correct or not, should not be considered limiting of the scope of the present application, which is limited only by the claims. The present application can be implemented in ways other than those specifically set forth herein without departing from the essential scope of the present application.

[0024] In the present text, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, amounts, contents and concentrations, are for the sake of brevity and convenience only. Therefore, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0025] In the present text, unless otherwise specified, "comprise", "include", "contain", "have" or similar words encompass the meaning of "consist of" and "consist essentially of", for example, "A comprises a" encompasses the meaning of "A comprises a and other" and "A comprises only a".

[0026] In the present text, for the sake of brevity, all possible combinations of the various technical features in the various embodiments or examples are not described. Therefore, as long as the combinations of the technical features do not contradict each other, the various technical features in the various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered as falling within the scope of the present specification.

[0027] The present application will be further described with reference to the following specific examples. It should be understood that these examples are intended to illustrate the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the present application after reading the content of the present application, and these equivalent forms also fall within the scope of the claims appended to the present application.

[0028] The following examples use apparatus and equipment that are conventional in the art. The experimental methods in the following examples, unless otherwise specified, are generally performed according to conventional conditions, or according to the conditions recommended by the manufacturer. The following examples use various raw materials, unless otherwise specified, all of which are conventional commercially available products, and the specifications thereof are conventional in the art. In the specification of the present application and in the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0029] There is an old saying in the steel industry that "copper and iron cannot be heated in the same furnace". A furnace that has been used to heat copper cannot be used to heat steel. When copper or copper oxide remains in the furnace when steel is heated, cracks similar to overburning appear on the surface of the steel. This is now known as the "copper embrittlement" phenomenon. The reason for the copper embrittlement phenomenon is that, due to the need for steel processing technology, the steel billet must be heated to above 1100°C (the melting point of copper is 1083°C) to meet the need for plastic processing of steel. At high temperatures, the copper that was originally in solid solution is exposed and becomes a liquid phase because the temperature is above its melting point. The liquid copper will erode the grain boundaries of the underlying matrix, resulting in a decrease in product performance or even scrap.

[0030] The present application takes advantage of the characteristics of copper embrittlement by heating the surface of copper-containing steel to melt the copper, then rapidly cooling it to solidify it, and controlling the depth of the "copper embrittlement layer". The steel is covered with a layer of copper during forging or rolling. The advantage is that it can avoid subsequent heat treatment process, simplify the production process, and improve production efficiency. The core idea of this technology patent is to melt the copper on the surface of copper-containing steel and form a copper plating layer on the surface of the steel after cooling, so that it has antibacterial properties.

[0031] The composition of the copper-containing steel required by the present application includes: copper content of 2wt.% to 4wt.%, Ni and Cu ratio of 1:2 to 1:3, B content of 10 to 20 ppm (mass ratio, one millionth), and the rest of the elements are determined according to the working conditions, and other alloying elements are added according to the requirements of the working conditions.

[0032] The preparation of copper-containing steel is divided into the following two ways:

[0033] 1): Buy or self-smelt steel ingot or plate containing the above-mentioned composition, characterized in that the content ratio of copper and nickel in the steel ingot or plate is (1:2) to (1:3), the content of B is 10 to 20 ppm, and there is no specific limitation on other alloying elements.

[0034] 2): Self-smelt: weigh and polish each different element to remove the oxide skin according to the pre-set alloy composition; vacuumize all alloys in the electric arc furnace to 10 -3Mpa; the alloy is smelted, all elements are melted and stirred for 5 minutes at high temperature, and then re-smelted after cooling, and the above process is repeated for more than 5 times to ensure that the alloy forms a uniform solid solution; after the last smelting, the material is poured according to the shape of the required material to form an ingot or a plate.

[0035] Example 1

[0036] A preparation method of a copper-containing antibacterial steel includes the following steps:

[0037] The copper-containing steel ingot is placed in a 1200℃ muffle furnace and heated for 5 minutes, and then the steel ingot is taken out for forging with a forging force of 200t and a rate of 5mm / s. The copper-containing antibacterial steel is obtained after the steel ingot is forged, and the surface of the copper-containing antibacterial steel is a red copper-rich antibacterial layer. The composition of the copper-containing steel ingot is: the mass percentage of copper is 3wt.%, the mass percentage of nickel is 1.5wt.%, the mass percentage of chromium is 13wt.%, the content of boron is 15ppm, and the balance is iron. The size of the copper-containing steel ingot is 100mm×100mm×50mm.

[0038] Example 2

[0039] The raw material composition is: the mass percentage of copper is 4wt.%, the mass percentage of nickel is 1.9wt.%, the mass percentage of chromium is 13wt.%, the content of boron is 20ppm, and the balance is iron alloy. After smelting, a plate with a size of 100mm×50mm×5mm is poured to obtain a copper-containing plate.

[0040] The induction heating device is placed in front of the rolling mill, and the plate is heated as shown in Figure 2 The heating power is 70KW, and the surface temperature of the plate can be raised to above 1150℃ after about 5s. The copper-containing plate is rolled, the roller speed of the rolling mill is set to be constant, and the compression amount is 0.5mm. The copper-containing antibacterial steel is obtained after rolling, and the surface of the copper-containing antibacterial steel is a red copper-rich antibacterial layer.

[0041] The copper-containing antibacterial steel prepared in the above examples is subjected to an antibacterial performance test, and the copper-containing antibacterial steel prepared by the present application has an excellent antibacterial and corrosion-resistant effect with a corrosion rate of less than 0.1mm / a in a 3.5% NaCl solution with an SRB concentration of less than 20000 / ml, a TGB concentration of less than 100000 / ml, and an FB of less than 25 / ml.

[0042] Example 3

[0043] The copper content is 2wt.%, the nickel content is 0.67wt.%, the boron content is 10ppm, the temperature of the muffle furnace is 1300℃, the heating time is 8min, and the rest is the same as in Example 1 to obtain a copper-containing antibacterial steel.

[0044] Example 4

[0045] The copper content is 3wt.%, the nickel content is 1.5wt.%, the boron content is 14ppm, the temperature of the muffle furnace is 1300℃, the heating time is 8min, and the rest is the same as in Example 1 to obtain a copper-containing antibacterial steel.

[0046] The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A method for producing a copper-containing antibacterial steel, characterized by, The method comprises the following steps: The copper-containing steel material is heated in an oxidizing atmosphere, and plastic deformation treatment is performed after the heating is completed to obtain copper-containing antibacterial steel with a copper layer on the surface; The composition of the copper-containing steel material comprises copper, nickel, boron and other alloy elements; the mass percentage of copper is 2wt.%-4wt.%, the ratio of the mass percentage of nickel to the mass percentage of copper is (1:2)-(1:3), the content of boron is 10ppm-20ppm, and the balance is other alloy elements; The heating is performed by using a box-type furnace or an induction heating device; When the box-type furnace is used for heating, the temperature of the box-type furnace is set to 1100-1300℃, and the heating time is set to 5-8min; When the induction heating device is used for heating, the heating power of the induction heating device is set to 70Kwa, and the heating time is set to 3-5s.

2. The method of producing a copper-containing antibacterial steel according to claim 1, characterized by, The oxidizing atmosphere is oxygen.

3. The method for preparing copper-containing antibacterial steel according to claim 1, characterized in that, The copper-containing steel material is heated in the oxidizing atmosphere until the temperature of the copper-containing steel material within 1mm of the surface is greater than 1100℃, and the temperature of the copper-containing steel material below 1mm of the surface is less than 1100℃, and then the heating is completed.

4. The method for preparing copper-containing antibacterial steel according to claim 1, characterized in that, The thickness of the copper layer on the surface of the copper-containing antibacterial steel is greater than 0mm and less than 1mm.

5. The method for preparing copper-containing antibacterial steel according to claim 1, characterized in that, The plastic deformation treatment is performed by forging or rolling.

6. The method for preparing copper-containing antibacterial steel according to claim 1, characterized in that, The copper-containing antibacterial steel obtained has a plate shape or a ingot shape.

7. The copper-containing antibacterial steel obtained by the method for preparing copper-containing antibacterial steel according to any one of claims 1-6.

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