CN106834806A - A kind of anti-corrosion kirsite and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of manufacturing nonferrous metal materials, and in particular relates to a corrosion-resistant zinc alloy containing beryllium and a preparation method thereof. The corrosion-resistant alloy of the present invention includes, in terms of mass percentages: 0.50-0.75% copper, 0.50-0.75% nickel, 0.05-0.10% titanium, 0.01-0.02% beryllium, 0.003-0.006% lanthanum, 0.006-0.01% cerium, impurities Content ≤ 0.05%; the balance is zinc. The corrosion-resistant zinc alloy is added with alloy elements by means of electrolytic copper, beryllium bronze, Zn-Ni-Ti intermediate alloy, and zinc foil-coated rare earth elements; die casting is adopted, and the alloy is then subjected to a heat treatment to obtain a corrosion-resistant zinc alloy. The corrosion potential of the corrosion-resistant zinc alloy is relatively positive, and corrosion is not easy to occur; even if corrosion occurs, the corrosion rate is very small, which greatly slows down the aging rate of the material. The invention has reasonable component design, simple and easy-to-control preparation process, and is convenient for large-scale industrial application.

Description

A kind of corrosion-resistant zinc alloy and preparation method thereof

technical field

The invention belongs to the technical field of nonferrous metal materials, and in particular relates to a corrosion-resistant zinc alloy and a preparation method thereof.

Background technique

Zinc alloy has low melting point, good mechanical properties, low processing energy consumption, and cheap and easy-to-obtain raw materials, which can effectively save materials and production costs. At present, zinc alloys have been widely used in daily hardware, mechanical parts, building materials decoration, electronic components, instruments and meters, commemorative coins, etc. At the same time, zinc alloys also have potential application prospects in many aspects.

Among zinc alloys, deformed zinc-copper-titanium alloys are widely used as structural materials. The commonly used wrought zinc-copper-titanium alloy has a copper content of 0.5% to 1.5% and a titanium content of 0.1% to 0.5%. The joint action of Cu and Ti in zinc-copper-titanium alloy makes it have excellent physical and mechanical properties, mainly as follows: high creep resistance, the time required for creep deformation to reach 1% is nearly 500 times that of pure zinc; The thermal expansion coefficient is about 30% lower than that of pure zinc; the tensile strength is comparable to that of α-brass annealed state, which is more than 50% higher than that of pure zinc; the forming and machining properties are excellent. However, in the actual use of zinc-copper-titanium alloy products, especially in hardware, bathroom, decoration and other humid environments containing Cl ^- , this alloy is prone to intergranular corrosion, pitting corrosion, etc., resulting in a decrease in surface quality and size. Unstable, anti-aging performance is reduced, which seriously limits its application range. Although the zinc alloy can be protected by plating to improve its corrosion resistance, there are always some factors in the process of processing and use that may cause the damage and fall off of the plating layer, exposing the zinc substrate to the corrosive medium and forming localized corrosion. . Therefore, improving the corrosion resistance of zinc alloy itself is the key to promoting the application of zinc alloy, and it has always been an important technical issue that the industry has paid close attention to.

Relevant studies have shown that adding different alloying elements to the zinc matrix and adjusting their addition range can improve the corrosion resistance of zinc alloys. Commonly added elements in the industry include aluminum, copper, magnesium, titanium, nickel, manganese, chromium and rare earth elements. However, corrosion-resistant zinc alloys containing Be have not been recorded in the prior art.

Contents of the invention

The invention mainly aims to solve the problem that deformed zinc-copper-titanium alloy has low corrosion resistance in a humid environment containing ^Cl- , and provides a corrosion-resistant zinc alloy composition and a melting preparation method thereof. The corrosion-resistant zinc alloy is composed of zinc, copper, nickel, titanium, beryllium, rare earth and unavoidable impurities, by adjusting and optimizing the coordination between Zn and Cu, Ti, Ni, Be, La, Ce and other alloy elements Ratio, while ensuring the mechanical properties of the multi-element zinc alloy, its corrosion resistance is also improved.

The invention relates to a corrosion-resistant zinc alloy, which contains beryllium.

The invention relates to a corrosion-resistant zinc alloy, which is characterized in that: in the corrosion-resistant zinc alloy, the mass percentage of beryllium is 0.01-0.05%.

A corrosion-resistant zinc alloy of the present invention is characterized in that: the corrosion-resistant zinc alloy contains Ni, and the mass percentage of Ni in the corrosion-resistant zinc alloy is 0.50-1.00%.

The invention relates to a corrosion-resistant zinc alloy, which contains copper, nickel, titanium, beryllium, rare earth elements and zinc.

As a preferred version, a corrosion-resistant zinc alloy of the present invention comprises the following components in terms of mass percentage:

Copper 0.50～1.00%,

Nickel 0.50～1.00%,

Titanium 0.05～0.20%,

Beryllium 0.01～0.05%,

Lanthanum 0.001～0.01%,

Ce 0.002～0.01%,

Impurity content≤0.05%;

The balance is the zinc.

As a further preferred solution, a corrosion-resistant zinc alloy of the present invention comprises the following components in terms of mass percentage:

Copper 0.50～0.75%, such as 0.50%, 0.52%, 0.55%, 0.58%, 0.6%, 0.62%, 0.64%, 0.68%, 0.71%, 0.73%, 0.75% can be used as a further preferred scheme;

Nickel 0.50～0.75%, such as 0.50%, 0.53%, 0.58%, 0.61%, 0.62%, 0.64%, 0.66%, 0.68%, 0.71%, 0.73%, 0.75% can be used as a further preferred scheme;

Titanium 0.05-0.10%, such as 0.05%, 0.06%, 0.07%, 0.082%, 0.091%, 0.1% can be used as a further preferred solution;

Beryllium 0.01～0.02%, such as 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02% can be used as a further preferred solution;

Lanthanum 0.003-0.006%, such as 0.003%, 0.004%, 0.005%, 0.006% can be used as a further preferred solution;

Ce 0.005-0.01%, such as 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01% can be used as a further preferred solution;

Impurity content≤0.05%;

The balance is the zinc.

A kind of preparation method of corrosion-resistant zinc alloy of the present invention comprises the following steps:

step one

Allocation and selection of copper source, nickel source, titanium source, beryllium source, rare earth source and zinc source according to the design group;

step two

Put the prepared copper source, nickel source, titanium source, beryllium source, rare earth source, and zinc source into the smelting furnace for melting, and cast to obtain ingots;

step three

Heat the ingot obtained in step 2 at 320-390° C., and after heat preservation, take it out of the furnace and air-cool to obtain a corrosion-resistant zinc alloy.

A kind of preparation method of corrosion-resistant zinc alloy of the present invention,

The copper source in step 1 is electrolytic copper and beryllium bronze, and the beryllium source is beryllium copper. The electrolytic copper is more preferably electrolytic copper with a purity above 99.9%; the beryllium copper is more preferably QBe2 beryllium copper.

The nickel source and titanium source described in step 1 are Zn-Ni-Ti ternary master alloy, preferably Zn-10Ni-2Ti ternary master alloy; more preferably Zn-10Ni-2Ti ternary master alloy prepared by vacuum melting .

The zinc source described in step 1 is pure zinc and Zn-Ni-Ti ternary master alloy, and the Zn-Ni-Ti ternary master alloy is preferably Zn-10Ni-2Ti ternary master alloy; more preferably, vacuum melting Prepared Zn-10Ni-2Ti ternary master alloy.

The rare earth source in step one is mixed rare earths of lanthanum and cerium. Preferably, in the mixed rare earth of lanthanum and cerium, Ce is 65wt.%, La is 34wt.%, and the balance is other rare earth elements. For industrial production, the lanthanum and cerium mixed rare earths are commercially available Ce+La mixed rare earths.

A method for preparing a corrosion-resistant zinc alloy of the present invention, when the copper source is electrolytic copper and beryllium bronze, the beryllium source is beryllium bronze, and the nickel source and titanium source are Zn-Ni-Ti ternary master alloy, The zinc source is pure zinc and Zn-Ni-Ti ternary master alloy, and when the rare earth source is mixed rare earth of lanthanum and cerium, the electrolytic copper, beryllium bronze and Zn-Ni-Ti ternary master alloy Place it at the bottom of a high-purity graphite crucible, and then place the prepared pure zinc on electrolytic copper, beryllium copper, and Zn-Ni-Ti ternary intermediate alloy, then put the graphite crucible into an intermediate frequency induction furnace, and first heat it up to pure zinc Melt, then raise the temperature to 900-1000°C, stir evenly after the electrolytic copper, beryllium bronze, and Zn-Ni-Ti ternary master alloy are completely melted, cool down to 800-850°C, and then use the lanthanum and cerium mixed rare earth Wrap it in zinc foil, put it into a melting furnace, melt it, let it stand still, and cast it into a steel mold after the temperature of the melt drops to 680-720°C to obtain an ingot. The zinc foil is made of pure zinc. The pure zinc is industrial pure zinc.

A method for preparing a corrosion-resistant zinc alloy of the present invention, in step 3, the ingot obtained in step 2 is put into a heating furnace, and kept at 320-390°C, preferably 350°C, for 2-3 hours, preferably 2.5 hours, After heat preservation, it is taken out of the furnace and air-cooled to obtain a corrosion-resistant zinc alloy.

The invention relates to a method for preparing a corrosion-resistant zinc alloy, the smelting method of which is non-vacuum smelting.

Principles and advantages

The corrosion-resistant zinc alloy involved in the present invention is a zinc alloy with good corrosion resistance formed by adding an appropriate amount of copper, nickel, titanium, beryllium and rare earth elements on the basis of industrially pure Zn. The alloy product can be used for hardware, In sanitary, decoration and other humid environments containing Cl ^- . The wrought zinc alloy materials used in hardware not only require excellent forming and machining properties, but also require good corrosion resistance in humid environments.

The present invention adds a proper amount of Be to the zinc alloy, which can reduce slag, improve purity, and improve fluidity during smelting; after the alloy is obtained, the added Be can form a dense protective oxide film on the surface of the alloy, which can reduce Surface oxidation and corrosion of Zn alloy at room temperature. At the same time, Be in the alloy can also change the morphology of the intermetallic compound of brittle impurity Fe, thereby improving the strength and plasticity of the alloy.

The present invention chooses to add an appropriate amount of Ni element, and through the synergistic effect of Ni and Be, the cathodic reaction of electrochemical corrosion can be inhibited, the corrosion product can be changed, and a dense film of alkaline chloride product is formed. The film has poor conductivity, thereby blocking zinc further corrosion of the alloy.

In the present invention, the addition of an appropriate amount of rare earth elements can refine the matrix structure, reduce the number of dendrites and the distance between dendrites; the rare earth can also interact with impurities segregated at grain boundaries to reduce segregation. Rare earth Ce can obviously refine the as-cast structure, improve the mechanical properties and local corrosion resistance of the alloy; La can refine the primary phase α phase of the zinc alloy, improve the morphology and distribution of the phase, and improve the plasticity and strength of the alloy. Heat treatment of the alloy at 350°C/2.5h can reduce the segregation of the alloy composition and make the structure more stable, so the corrosion resistance can be improved.

Compared with the existing zinc-copper-titanium alloy, the present invention has the following advantages and effects:

(1) The preparation process is simple: beryllium bronze and Zn-Ni-Ti ternary master alloy are added to pure zinc, and rare earth elements are covered with zinc foil, and graded mixing and melting are carried out. The operation is convenient and the composition can be uniform and stable.

(2) Excellent corrosion resistance: the addition of Ni and Be can form a dense film, which can hinder the contact between the corrosive medium and the material surface, and inhibit the further development of corrosion. Electrochemical experiments were carried out in tap water and 3.5wt.% NaCl solution respectively, and the corrosion potential of the alloy of the present invention became positive, and the corrosion current density decreased significantly, which means that the corrosion rate was greatly reduced.

(3) Good overall performance: by adding an appropriate amount of rare earth elements, the alloy structure is refined. Therefore, the alloy has good mechanical properties while significantly improving its corrosion resistance. The test results show that the alloy of the present invention has a tensile strength of more than 120MPa and an elongation of more than 8% after homogenization heat treatment at 350°C/2.5h in the as-cast state; After /6h annealing treatment, the tensile strength can reach more than 220MPa, and the elongation can reach more than 35%.

detailed description

The technical solutions of the present invention are further specifically described below through examples. It should be noted that the following examples and comparative examples are only used to explain the present invention, and should not be regarded as limiting the scope of the claims of the present invention.

Examples and comparative examples

In the present invention, the prepared electrolytic copper, beryllium bronze and Zn-Ni-Ti ternary master alloy are placed on the bottom of the high-purity graphite crucible, and then the prepared pure zinc is placed on the electrolytic copper, beryllium bronze, Zn-Ni-Ti Put the graphite crucible on top of the ternary master alloy, then put the graphite crucible into the medium frequency induction furnace, first raise the temperature until the pure zinc melts, then raise the temperature to 900-1000°C, and wait until the electrolytic copper, beryllium bronze and Zn-Ni-Ti ternary master alloy are completely melted Afterwards, stir evenly, lower the temperature to 800-850°C, then wrap the prepared lanthanum and cerium mixed rare earth with zinc foil, put it into the melting furnace, melt it, let it stand, and cast it after the melt temperature drops to 680-720°C In a steel mould, an ingot is obtained. Then the alloy is subjected to 350°C/2.5h homogenization heat treatment. Finally, the alloy was sampled for electrochemical corrosion experiments.

The alloy compositions of each embodiment and comparative example are shown in Table 1, and the experimental data of electrochemical corrosion are shown in Table 2.

Table 1 each embodiment and the alloy composition (wt.%) of comparative example

The electrochemical corrosion performance parameters of the products of each embodiment and comparative examples in table 2

It can be seen from the data in Table 2 that with the optimized alloying ratio of the present invention, Examples 1, 2, and 3 all achieved better corrosion resistance. Comparative example 1 lacks Ni because of alloy proportioning, and its corrosion potential is negative to embodiment 1 and embodiment 2, is more susceptible to corrosion; After corrosion begins, corrosion current density increases greatly, and the corrosion rate of comparative example 1 in tap water is about 8.9 times that of Example 1, and the corrosion rate in 3.5wt.% NaCl solution is 6.8 times. From the above comparison, it can be seen that the addition of Ni element can improve the corrosion resistance of zinc alloy, because Ni element inhibits the electrochemical cathodic reaction, promotes the formation of basic zinc chloride film, and further hinders the corrosion of zinc alloy.

The alloy ratio of Comparative Example 2 lacks Be, and the corrosion potential becomes negative. The corrosion rate in tap water is about 7.8 times that of Example 1, and the corrosion rate in 3.5wt.% NaCl solution is 5.9 times. From the above comparison, it can be seen that the addition of Be element can improve the corrosion resistance of zinc alloy, because Be can form a dense protective oxide film on the alloy surface, which can reduce the surface oxidation and corrosion of Zn alloy at room temperature.

The alloy ratio of Comparative Example 3 lacks rare earth elements, and the corrosion potential becomes negative. The corrosion rate in tap water is about 3.7 times that of Example 1, and the corrosion rate in 3.5wt.% NaCl solution is 4.1 times. Rare earth elements mainly play the role of refining grains and purifying melt in zinc alloy.

The alloy proportion of Comparative Example 4 lacks Ni and Be, and the corrosion potential becomes negative, and its corrosion rate in tap water is about 8.9 times that of Example 1, and the corrosion rate in 3.5wt.% NaCl solution is 7.6 times, From Example 1 and Comparative Examples 1, 2, and 4, it mainly shows that there may be a synergistic effect between Ni and Be.

Through the comparison of Example 1 and Examples 2 and 3, it is found that after the components are optimized, the corrosion resistance of the product obtained in Example 1 is better than that of Example 2 and Example 3.

It can be seen that the corrosion potential of the corrosion-resistant zinc alloy of the present invention is relatively positive, and corrosion is not easy to occur. After corrosion occurs, its corrosion rate is small, which greatly slows down the aging process of materials due to corrosion, thereby providing an effective technology for new product development. way.

Claims (10)

1. a kind of anti-corrosion kirsite, it is characterised in that：Contain beryllium in the anti-corrosion kirsite.

2. a kind of anti-corrosion kirsite according to claim 1, it is characterised in that：In the anti-corrosion kirsite, the quality of beryllium Percentage composition is 0.01~0.05%.

3. a kind of anti-corrosion kirsite according to claim 2, it is characterised in that：Contain Ni in the anti-corrosion kirsite, institute State in anti-corrosion kirsite, the weight/mass percentage composition of Ni is 0.50~1.00%.

4. a kind of anti-corrosion kirsite according to claim 3, it is characterised in that：In the anti-corrosion kirsite containing copper, nickel, Titanium, beryllium, rare earth element and zinc.

5. a kind of anti-corrosion kirsite according to claim 4, it is characterised in that：The anti-corrosion kirsite is with mass percent Meter includes following components：

Copper 0.50~1.00%,

Nickel 0.50~1.00%,

Titanium 0.05~0.20%,

Beryllium 0.01~0.05%,

Lanthanum 0.001~0.01%,

Cerium 0.002~0.01%,

Impurity content≤0.05%；

The balance of zinc.

6. a kind of anti-corrosion kirsite according to claim 5, it is characterised in that：The anti-corrosion kirsite is with mass percent Meter includes following components：

Copper 0.50~0.75%,

Nickel 0.50~0.75%,

Titanium 0.05~0.10%,

Beryllium 0.01~0.02%,

Lanthanum 0.003~0.006%,

Cerium 0.005~0.01%,

Impurity content≤0.05%；

The balance of zinc.

7. a kind of method for preparing the anti-corrosion kirsite as described in claim 1~6 any one, it is characterised in that including following steps Suddenly：

Step one

Match somebody with somebody by design component and take copper source, nickel source, titanium source, beryllium source, rare earth source, zinc source；

Step 2

Melting in smelting furnace, casting will be added to obtain ingot casting with the copper source, nickel source, titanium source, beryllium source, rare earth source, zinc source that take；

Step 3

Step 2 gained ingot casting is incubated in 320~390 DEG C, after insulation, air cooling of coming out of the stove obtains anti-corrosion kirsite.

8. the preparation method of a kind of anti-corrosion kirsite according to claim 7, it is characterised in that：

Copper source is cathode copper and beryllium-bronze；

The beryllium source is beryllium-bronze；

The nickel source, titanium source are Zn-Ni-Ti ternary intermediate alloys；

The zinc source is pure zinc and Zn-Ni-Ti ternary intermediate alloys；

The rare earth source is lanthanum, cerium mischmetal.

9. the preparation method of a kind of anti-corrosion kirsite according to claim 8, it is characterised in that：

When copper source is cathode copper and beryllium-bronze, the beryllium source is beryllium-bronze, and the nickel source, titanium source are in Zn-Ni-Ti ternarys Between alloy, the zinc source be pure zinc and Zn-Ni-Ti ternary intermediate alloys, the rare earth source be lanthanum, cerium mischmetal when, first will High purity graphite crucible bottom is placed in the cathode copper, beryllium-bronze, Zn-Ni-Ti ternary intermediate alloys for taking, then by with the pure zinc for taking It is placed on beryllium-bronze, Zn-Ni-Ti ternary intermediate alloys, graphite crucible is then put into intermediate frequency furnace, is first warming up to pure zinc Fusing, then it is warming up to 900~1000 DEG C, stirring is equal after copper to be electrolysed, beryllium-bronze, Zn-Ni-Ti ternary intermediate alloys are completely melt It is even, 800~850 DEG C are cooled to, then will be wrapped with the lanthanum, cerium mischmetal zinc paper tinsel that take, it is put into smelting furnace, melting, stand, In casting in steel mould after melt temperature is down to 680~720 DEG C, ingot casting is obtained.

10. the preparation method of a kind of anti-corrosion kirsite according to claim 7, it is characterised in that：

In step 3, step 2 gained ingot casting is put into chamber type electric resistance furnace, is incubated 2~3 hours in 320~390 DEG C, insulation Afterwards, come out of the stove air cooling, obtain anti-corrosion kirsite.