A zinc alloy sacrificial anode material suitable for high-temperature seawater environment

Abstract

The present invention discloses a zinc alloy sacrificial anode material suitable for high-temperature seawater environment, belonging to the field of electrochemical protection materials. By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 5.55 - 5.25%, manganese 5.51 - 5.52%, and the balance is zinc, and the impurity content meets the relevant requirements of GB / T475-2558 "Zinc Ingot". It uses zinc as the raw material, only adds magnesium and manganese elements, and is prepared by the casting method. The current efficiency of this material in the seawater environment of 55°C - 85°C is more than 95%, and the open circuit potential is negative to -1.53V SCE , and the working potential is negative to -1.55V SCE , and the capacitance is greater than 795 A·h·kg ‑1 , the corrosion morphology is uniform, the corrosion products fall off automatically, it has excellent electrochemical properties, is suitable for cathodic protection in the seawater environment of 55°C - 80°C, and has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of electrochemical protection materials, and particularly relates to a zinc alloy sacrificial anode material suitable for high-temperature seawater environment. Background Art

[0002] Disclosing the information of this background art section is only intended to increase the understanding of the overall background of the present invention, and is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] With the implementation of the marine power strategy, a large number of marine engineering equipment are applied to various real-sea environments. Some equipment or components in these engineering equipment will work in seawater at relatively high temperatures, and the environmental temperature will reach above 55°C, even 85°C. When the traditional Zn-Al-Cd anode material is used in an environment above 55°C, the current efficiency is greatly reduced, the potential shifts positively, and it cannot meet the needs of cathodic protection. Some sacrificial anode materials suitable for high-temperature environments have been developed in previous studies. Some of these materials use more alloying elements in the formula, making the smelting process more complex and increasing the production cost; some materials have a narrow applicable temperature range and cannot effectively meet the requirements of complex working conditions; some materials have high requirements for the content of impurity elements in the raw materials. Therefore, there is an urgent need to develop a new type of sacrificial anode material that is suitable for a wide range of high-temperature environments, has fewer alloying elements, a simple smelting process, and low requirements for the impurity content of raw materials. Summary of the Invention

[0004] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a zinc alloy sacrificial anode material suitable for high-temperature seawater environment. The zinc alloy sacrificial anode material provided by the present invention has high electrochemical activity, a sufficiently negative working potential, a large capacitance, a high current efficiency, and a uniform corrosion morphology in seawater at 55°C - 85°C. The corrosion products automatically fall off. It has few alloying elements, a simple production process, and low requirements for the impurity content of raw materials.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] In the first aspect of the present invention, a zinc alloy sacrificial anode material suitable for high-temperature seawater environment is provided. By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 5.55 - 5.25%, manganese 5.51 - 5.52%, and the balance is zinc. The impurity content meets the relevant requirements of GB / T475 - 2558 "Zinc Ingot".

[0007] The present invention uses an alloying method to controllably add elements magnesium and manganese to zinc, improving the electrochemical performance of the sacrificial anode material in a seawater environment at 55°C - 85°C and enhancing its dissolution effect. Adding 5.55 - 5.25% of magnesium can form a solid solution with zinc, making the alloy dissolve more uniformly and significantly increasing its capacitance. Adding 5.51 - 5.52% of manganese can effectively inhibit the adverse effects of impurity elements, further refining the grains of the anode material and preventing intergranular corrosion.

[0008] Preferably, the current efficiency of the zinc alloy sacrificial anode material in a seawater environment at 55°C - 85°C is greater than 95%, and the open circuit potential is more negative than -1.53V SCE , and the working potential is more negative than -1.55V SCE , and the capacitance is greater than 795 A·h·kg -1 .

[0009] Preferably, for the high-temperature zinc alloy sacrificial anode material, by weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 5.55%, manganese 5.51%, and the balance is zinc.

[0010] Preferably, for the high-temperature zinc alloy sacrificial anode material, by weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 5.15%, manganese 5.52%, and the balance is zinc.

[0011] Preferably, for the high-temperature zinc alloy sacrificial anode material, by weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 5.25%, manganese 5.51%, and the balance is zinc.

[0012] In the second aspect of the present invention, a method for preparing the above-mentioned zinc alloy sacrificial anode material is provided, including the following steps: using zinc as the raw material, adding magnesium and manganese elements, and using a melting and casting method to melt and prepare the zinc alloy sacrificial anode material.

[0013] Preferably, the melting and casting method is to use a muffle furnace for melting.

[0014] Preferably, the preparation method specifically includes the following steps:

[0015] Place the zinc ingot in a graphite crucible, adjust the muffle furnace to heat up for melting. After the zinc ingot is completely melted, add magnesium and manganese elements in sequence, and stir to quickly melt and evenly distribute the alloy elements;

[0016] Stop stirring, let it stand still to separate the dross and the melt, and skim off the dross; pour the melt into a preheated mold, and after natural cooling, open the mold to take out the zinc alloy sacrificial anode material, thus obtaining it.

[0017] More preferably, for the stirring, the stirring speed is 45 revolutions per minute, and the stirring time is 1 minute.

[0018] Further preferably, the conditions for the melting and casting processes are as follows: the melting temperature is 755 - 795 °C, the melting time is 13 - 25 minutes, stirring promotes the uniformity of components and the floating of inclusions, standing for 2 - 3 minutes, skimming off the dross and then casting into the mold.

[0019] Further preferably, the conditions for the melting and casting processes are as follows: the melting temperature is 725 °C, the melting time is 15 minutes, stirring at a speed of 45 revolutions per minute for 1 minute promotes the uniformity of components and the floating of inclusions, standing for 1 minute, skimming the slag, and casting into the mold.

[0020] Preferably, the preheating is to preheat to above 355 °C. The reason for preheating the mold is to improve the fluidity of the molten liquid in the mold.

[0021] The zinc alloy sacrificial anode material provided by the present invention is applicable to the seawater environment at 55 °C - 85 °C, with a sufficiently negative working potential, a large capacitance, a high current efficiency, complete activation, a uniform corrosion morphology, and automatic shedding of corrosion products, and has excellent electrochemical protection performance. Therefore, in the third aspect of the present invention, a method for metal anti-corrosion in a seawater environment at 55 °C - 85 °C is provided. The above zinc alloy sacrificial anode material is used as the protection electrode and is connected to the metal to be protected to form a primary battery. The zinc alloy sacrificial anode material acts as the negative electrode and undergoes an oxidation reaction and is consumed, while the metal to be protected acts as the positive electrode to avoid corrosion.

[0022] The beneficial effects of the present invention are as follows:

[0023] In order to improve the electrochemical performance of the sacrificial anode material in a high-temperature marine environment, the present invention adjusts the composition and content of alloying elements and optimizes the melting process, thereby improving the electrochemical performance of the zinc alloy sacrificial anode in seawater at 55 °C - 85 °C and meeting the long-term anti-corrosion requirements of marine engineering equipment in a high-temperature environment. Specifically, by adding elements magnesium and manganese, the structure of the zinc alloy sacrificial anode is improved, the grain is refined, and the zinc alloy high-temperature sacrificial anode has good electrochemical performance in a high-temperature seawater medium environment, with a uniform corrosion morphology, automatic shedding of corrosion products, and has a high current efficiency and a sufficiently negative working potential, a large capacitance, complete activation, and excellent electrochemical protection performance; in the seawater environment at 55 °C - 85 °C, the current efficiency is higher than 95%, the open-circuit potential is more negative than -1.53 V SCE , the working potential is more negative than -1.55 V SCE , the capacitance is greater than 795 A·h·kg -1 ; it is applicable to cathodic protection in the seawater environment at 55 °C - 85 °C and has broad application prospects.

[0024] The raw materials of the zinc alloy high-temperature sacrificial anode material of the present invention do not contain toxic and harmful heavy metal elements, are safe and environmentally friendly, and are prepared by the melting method, and the melting process is simple to operate. Description of the Drawings

[0025] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0026] Figure 1 Surface corrosion morphology diagram of the zinc alloy sacrificial anode material obtained in the embodiment of the present invention in seawater at 55 °C by using an accelerated test method according to the requirements of GB / T 17848-1999;

[0027] Figure 2 Surface corrosion morphology diagram of the zinc alloy sacrificial anode material obtained in the embodiment of the present invention in seawater at 85 °C by using an accelerated test method according to the requirements of GB / T 17848-1999. Detailed implementation manners

[0028] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0029] Embodiment 1

[0030] A preparation method of a zinc alloy sacrificial anode material suitable for a high-temperature seawater environment, the components of the zinc alloy sacrificial anode material are shown in Table 1, and the method includes the following steps:

[0031] (1) Weigh 1.5 kg of zinc ingots into a graphite crucible, adjust the muffle furnace to heat up to 725 °C for melting, and the melting time is 15 minutes; after the aluminum ingots are completely melted, add the weighed magnesium and manganese in sequence, and stir at a speed of 45 revolutions per minute with a graphite rod for 1 minute to quickly melt and evenly distribute the alloying elements;

[0032] (2) Let it stand for 1 minute to separate the dross and the melt, skim off the upper dross and then pour it into a preheated mold, and take out the anode after natural cooling and opening the mold.

[0033] Embodiment 2

[0034] A preparation method of a zinc alloy sacrificial anode material suitable for a high-temperature seawater environment, the components of the zinc alloy sacrificial anode material are shown in Table 1, and the preparation steps are the same as those in Embodiment 1.

[0035] Embodiment 3

[0036] A preparation method of a zinc alloy sacrificial anode material suitable for a high-temperature seawater environment, the components of the zinc alloy sacrificial anode material are shown in Table 1, and the preparation steps are the same as those in Embodiment 1.

[0037] Table 1 Composition list of zinc alloy sacrificial anode material

[0038]

[0039] Experimental Example 1

[0040] In accordance with the requirements of GB / T 17848-1999, an accelerated experiment method was adopted to study the electrochemical performance of the high-temperature sacrificial anode material of zinc alloy prepared in the examples in seawater at 55°C - 85°C. All the seawater was natural seawater from the Aoshan Bay in Jimo District, Qingdao. The electrolytic cell for the experiment was placed in a constant temperature oven at 55°C - 85°C, and the measured electrochemical parameters are shown in Table 2 below.

[0041] Table 2 Electrochemical performance of the sacrificial anode material of zinc alloy prepared in the examples in seawater at 55°C and 85°C

[0042]

[0043]

[0044] Experimental Example 2

[0045] In accordance with the requirements of GB / T 17848-1999, an accelerated experiment method was adopted to study the surface corrosion morphology of the high-temperature sacrificial anode material of zinc alloy prepared in the examples in seawater at 55°C - 85°C. All the seawater was natural seawater from the Aoshan Bay in Jimo District, Qingdao. By controlling relevant parameters in the laboratory, an environment of 55°C - 85°C was simulated: the electrolytic cell for the electrochemical experiment was placed in a constant temperature oven at 55°C - 85°C.

[0046] Figure 1 and Figure 2 are respectively the surface corrosion morphology diagrams of the sacrificial anode material of zinc alloy obtained in the examples of the present invention in seawater at 55°C and 85°C by adopting the accelerated experiment method in accordance with the requirements of GB / T17848-1999. From left to right are the sacrificial anode materials of zinc alloy obtained in Example 1, the sacrificial anode materials of zinc alloy obtained in Example 2, and the sacrificial anode materials of zinc alloy obtained in Example 3. From Figure 1 it can be seen that the corrosion morphologies of the sacrificial anode materials of zinc alloy prepared in Examples 1 - 3 of the present invention are very uniform, and the corrosion products can all fall off automatically.

[0047] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A zinc alloy sacrificial anode material suitable for high-temperature seawater environment, characterized in that, By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 0.05 - 0.25%, manganese 0.01 - 0.02%, the balance being zinc, and the impurity content meets the requirements of GB / T470 - 2008; The current efficiency of the zinc alloy sacrificial anode material is higher than 95% in the seawater environment at 80°C, and the open circuit potential is more negative than -1.03V SCE , and the working potential is more negative than -1.00V SCE , and the capacitance is greater than 790 A·h·kg -1 .

2. The zinc alloy sacrificial anode material according to claim 1, characterized in that By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 0.05%, manganese 0.01%, the balance being zinc.

3. The zinc alloy sacrificial anode material according to claim 1, characterized in that, By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 0.15%, manganese 0.02%, the balance being zinc.

4. The zinc alloy sacrificial anode material according to claim 1, characterized in that By weight percentage, the components of the zinc alloy sacrificial anode material are: magnesium 0.25%, manganese 0.01%, the balance being zinc.

5. The preparation method of the zinc alloy sacrificial anode material according to any one of claims 1-4, characterized in that, It includes the following steps: Using zinc as the raw material, adding magnesium and manganese elements, and adopting the melting and casting method to melt and prepare the zinc alloy sacrificial anode material.

6. The preparation method according to claim 5, characterized in that, The melting and casting method is to use a muffle furnace for melting.

7. The preparation method according to claim 5, characterized in that, The specific preparation method includes the following steps: Put the zinc ingot in a graphite crucible, adjust the muffle furnace to heat up for melting. After the zinc ingot is completely melted, add magnesium and manganese elements in sequence, and stir to make the alloy elements quickly melt and distribute evenly; Stop stirring, let it stand still to separate the dross and the melt, and skim off the dross; pour the melt into a preheated mold, and after natural cooling, open the mold to take out the zinc alloy sacrificial anode material, thus obtaining it.

8. The preparation method according to claim 7, characterized in that, For the stirring, the stirring speed is 40 revolutions per minute, and the stirring time is 1 minute.

9. The preparation method according to claim 7, characterized in that, The conditions for the melting and casting process are: melting temperature: 700 - 790 °C, melting time 13 - 20 minutes, stirring to promote the uniformity of components and the floating of inclusions, standing still for 2 - 3 minutes, skimming off the dross and then pouring into the mold.

10. The preparation method according to claim 7, characterized in that, The conditions for the melting and casting process are: melting temperature: 720 °C, melting time 15 minutes, stirring at a speed of 40 revolutions per minute for 1 minute to promote the uniformity of components and the floating of inclusions, standing still for 1 minute, skimming off the dross, and pouring into the mold.

11. A method for metal corrosion prevention in a seawater environment at 50°C - 80°C, characterized in that, Using the zinc alloy sacrificial anode material according to any one of claims 1 - 4 as the protection electrode, connecting it with the metal to be protected to form a primary battery, the zinc alloy sacrificial anode material acts as the negative electrode and undergoes an oxidation reaction and is consumed, while the metal to be protected acts as the positive electrode to avoid corrosion.

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