High-temperature-resistant sacrificial anode material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant sacrificial anode material which is prepared from the following raw material components in percentage by mass: 3 to 4 weight percent of Zn, 0.05 to 0.06 weight percent of In, 1 to 2 weight percent of Mg, 0.07 weight percent of Ti, 0.14 to 0.15 weight percent of Si and the balance of Al. The invention further discloses a preparation method of the high-temperature-resistant sacrificial anode material. The preparation method comprises the following specific steps that 1, the raw materials are weighed according to the mass percent; step 2, heating and smelting three materials of Al, Zn and Mg; 3, a certain amount of In, Ti and Si are sequentially added into the material obtained in the step 1, then electromagnetic stirring is carried out, furnace cooling is carried out after stirring is carried out for 10 min, and a metal ingot is formed; and 4, the metal ingot is smelted again after being reversed forwards and backwards, and the uniform aluminum-based sacrificial anode material is obtained. And 5, the aluminum-based sacrificial anode material is rolled and then subjected to heat treatment, and the high-temperature-resistant sacrificial anode material is obtained. The high-temperature-resistant sacrificial anode material provided by the invention has excellent high-temperature resistance and optimized mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal corrosion protection materials, and relates to a high temperature resistant sacrificial anode material. The present invention also relates to a method for preparing the high temperature resistant sacrificial anode material. Background Art

[0002] During the exploitation of oil and gas fields, as the depth of the well increases, the wellbore will face corrosive environments such as high temperature, acidic media, and brine. Common anti-corrosion measures include the use of corrosion-resistant alloys or anti-corrosion coatings, the addition of corrosion inhibitors, and cathodic protection. Among them, the use of corrosion-resistant alloys or anti-corrosion coatings faces the problem of high costs; the use of corrosion inhibitors not only requires long-term deployment, but also requires selection for different corrosive media; cathodic protection is a method of protecting the target metal using the principle of the galvanic cell. A metal with strong reducing properties is used as a protective electrode and connected to the protected metal to form a galvanic cell. The metal with strong reducing properties will be sacrificed as the negative electrode to undergo redox reactions, and the protected metal will be used as the positive electrode to avoid corrosion. This method consumes and sacrifices the metal as the anode, that is, the negative electrode of the galvanic cell, and protects the cathode metal, that is, the positive electrode of the galvanic cell. As long as electrochemistry occurs, the sacrificial anode method can protect the target material.

[0003] However, at high temperatures, the anode material may undergo polarity reversal, that is, the closed-circuit potential of the sacrificial anode becomes more positive than the potential of the cathode. The potential of the anode is more positive than the protective potential of the steel pipe, and it loses its protective effect. Summary of the invention

[0004] The purpose of the present invention is to provide a high temperature resistant sacrificial anode material, which solves the problem of high temperature resistance difference of anode materials in existing marine oil and gas field equipment.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned high temperature resistant sacrificial anode material.

[0006] Another object of the present invention is to provide application of the above-mentioned high temperature resistant sacrificial anode material.

[0007] The technical solution adopted by the present invention is that the high temperature resistant sacrificial anode material is composed of the following raw material components in terms of mass percentage: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance.

[0008] Another technical solution adopted by the present invention is a method for preparing a high temperature resistant sacrificial anode material, and the specific steps are as follows: Step 1: Weigh the following raw materials by mass percentage: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance; Step 2: heating and melting the three materials of Al, Zn and Mg; Step 3: Add a certain amount of In, Ti, and Si to the material obtained in step 1 in sequence, and then perform electromagnetic stirring. After stirring for 10 minutes, cool with the furnace to form a metal ingot; Step 4: Turn the metal ingot upside down and re-smelt it to obtain a uniform aluminum-based sacrificial anode material; Step 5: The aluminum-based sacrificial anode material is rolled and then heat-treated to obtain a high-temperature resistant sacrificial anode material.

[0009] Another technical solution of the present invention is also characterized in that: The specific process of step 2: The three materials of Al, Zn and Mg weighed in step 1 are placed in a vacuum furnace for smelting, with a vacuum degree of ≤1*10-3Pa and a smelting temperature of ≥600°C, until they are melted.

[0010] The specific process of step 3: Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in sequence, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the above three elements are added, start electromagnetic stirring. After stirring for 10 minutes, turn off the power of the vacuum furnace and cool it with the furnace to form a metal ingot.

[0011] The specific process of step 4: The metal ingot is taken out, turned upside down and put back into the vacuum furnace for re-smelting. The process is repeated 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

[0012] The specific process of step 5: Step 5.1: synchronously rolling the aluminum-based sacrificial anode material obtained in step 4, with a total pressing amount of 40-60%, and a pressing amount of 5% required for each rolling; Step 5.2: The synchronously rolled material is subjected to stress relief at 150°C for 24 hours; then subjected to aging treatment, first at 250°C for 1-2 hours, and then at 200°C for 10-20 hours, to finally obtain a high temperature resistant sacrificial anode material.

[0013] Another technical solution adopted by the present invention is the application of high-performance carbon dioxide corrosion inhibitor for surface corrosion inhibition of metal equipment in oil and gas fields.

[0014] The beneficial effects of the present invention are: The high temperature resistant sacrificial anode material provided by the present invention has, first, excellent high temperature resistance: through the precise ratio in the material formula, especially the addition of Mg, Zn and Si elements, the material of the present invention generates two precipitation phases of MgZn2 and Mg2Si under high temperature environment. These precipitation phases can effectively stabilize the structure of the anode material at high temperature and prevent the occurrence of polarity reversal, thereby ensuring that the anode can still provide effective cathodic protection in a high temperature environment. Second, it has optimized mechanical properties: the presence of MgZn2 and Mg2Si precipitation phases not only improves the high temperature resistance and corrosion resistance, but also improves the mechanical properties of the material. This makes the anode material have higher stability and durability in high temperature and high pressure environments, avoiding the failure of the material due to the decline of mechanical properties. Third, it has a wide range of industrial applications: the comprehensive performance of the material of the present invention makes it have a wide range of application prospects in marine oil and gas field equipment and other high temperature corrosion environments. Its preparation method is simple and efficient, suitable for large-scale industrial production, and has significant economic value and application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The open circuit potential test results of the high temperature resistant sacrificial anode material of the present invention and the zinc anode and the aluminum anode are shown in FIG. Figure 2 The corrosion morphology of the high temperature resistant sacrificial anode material of the present invention and the zinc anode and the aluminum anode before rust removal is shown. DETAILED DESCRIPTION

[0016] The present invention is described in detail below in conjunction with specific implementation modes.

[0017] The high temperature resistant sacrificial anode material is composed of the following raw material components in terms of mass percentage: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance.

[0018] The preparation method of high temperature resistant sacrificial anode material comprises the following specific steps: Step 1: Weigh the following raw materials by mass percentage: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance; Step 2: Place the three materials of Al, Zn and Mg weighed in step 1 in a vacuum furnace for smelting, with a vacuum degree of ≤1*10-3Pa and a smelting temperature of ≥600°C, until they melt.

[0019] Step 3: Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in sequence, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the addition of the above three elements is completed, start electromagnetic stirring, stir for 10 minutes, turn off the power of the vacuum furnace and cool with the furnace to form a metal ingot.

[0020] Step 4: Take out the metal ingot, turn it upside down and put it back into the vacuum furnace for re-smelting. Repeat this process 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

[0021] Step 5: Step 5.1: The aluminum-based sacrificial anode material obtained in step 4 is synchronously rolled, with a total pressing amount of 40-60%, and the pressing amount required for each rolling is 5%; Step 5.2: The synchronously rolled material is subjected to stress relief at 150°C for 24 hours; then subjected to aging treatment, first at 250°C for 1-2 hours, and then at 200°C for 10-20 hours, to finally obtain a high temperature resistant sacrificial anode material.

[0022] The application of high temperature resistant sacrificial anode materials is used for surface corrosion inhibition of offshore oil and gas production equipment.

[0023] Example 1 The preparation method of high temperature resistant sacrificial anode material comprises the following specific steps: Step 1: Weigh the following raw materials according to mass percentage: 3wt% Zn, 0.05wt% In, 1wt% Mg, 0.07wt% Ti, 0.14wt% Si, and Al as the balance.

[0024] Step 2: Heat and melt the three materials Al, Zn and Mg; Place the three materials Al, Zn and Mg weighed in step 1 in a vacuum furnace for melting, and the vacuum degree is ≤1*10 -3 Pa, melting temperature ≥ 600℃, until melted.

[0025] Step 3: Add In, Ti and Si in sequence to the material obtained in step 1, and then perform electromagnetic stirring. After stirring for 10 minutes, cool with the furnace to form a metal ingot; Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in sequence, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the addition of the above three elements is completed, start electromagnetic stirring. After stirring for 10 minutes, turn off the power of the vacuum furnace and cool with the furnace to form a metal ingot.

[0026] Step 4: Turn the metal ingot upside down and re-smelt it to obtain a uniform aluminum-based sacrificial anode material; take out the metal ingot, turn it upside down and put it back into the vacuum furnace for re-smelting, repeat this process 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

[0027] Step 5: After rolling, heat-treat the aluminum-based sacrificial anode material to obtain a high-temperature resistant sacrificial anode material. Step 5.1: Synchronously roll the aluminum-based sacrificial anode material obtained in step 4, with a total downward pressure of 40%, and a downward pressure of 5% required for each rolling; Step 5.2: Stress relief of the synchronously rolled material at 150°C for 24 hours; then perform aging treatment, first at 250°C for 1 hour, and then at 200°C for 10 hours, to finally obtain a high-temperature resistant sacrificial anode material.

[0028] Example 2 The preparation method of high temperature resistant sacrificial anode material comprises the following specific steps: Step 1: Weigh the following raw materials according to mass percentage: 4wt% Zn, 0.06wt% In, 2wt% Mg, 0.07wt% Ti, 0.15wt% Si, and Al as the balance.

[0029] Step 2: Heat and melt the three materials Al, Zn and Mg; Place the three materials Al, Zn and Mg weighed in step 1 in a vacuum furnace for melting, and the vacuum degree is ≤1*10 -3 Pa, melting temperature ≥ 600℃, until melted.

[0030] Step 3: Add In, Ti and Si to the material obtained in step 1 in turn, and then perform electromagnetic stirring. After stirring for 10 minutes, cool with the furnace to form a metal ingot; Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in turn, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the addition of the above three elements is completed, start electromagnetic stirring. After stirring for 10 minutes, turn off the power of the vacuum furnace and cool with the furnace to form a metal ingot.

[0031] Step 4: Turn the metal ingot upside down and re-smelt it to obtain a uniform aluminum-based sacrificial anode material; take out the metal ingot, turn it upside down and put it back into the vacuum furnace for re-smelting, repeat this process 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

[0032] Step 5: After rolling, heat-treat the aluminum-based sacrificial anode material to obtain a high-temperature resistant sacrificial anode material. Step 5.1: Synchronously roll the aluminum-based sacrificial anode material obtained in step 4, with a total pressing amount of 60%, and a pressing amount of 5% required for each rolling; Step 5.2: Stress relief of the synchronously rolled material at 150°C for 24 hours; then perform aging treatment, first at 250°C for 2 hours, and then at 200°C for 20 hours, to finally obtain a high-temperature resistant sacrificial anode material.

[0033] Example 3 The preparation method of high temperature resistant sacrificial anode material comprises the following specific steps: Step 1: Weigh the following raw materials by mass percentage: 3.5wt% Zn, 0.055wt% In, 1.5wt% Mg, 0.07wt% Ti, 0.145wt% Si, and Al as the balance.

[0034] Step 2: Heat and melt the three materials Al, Zn and Mg; Place the three materials Al, Zn and Mg weighed in step 1 in a vacuum furnace for melting, and the vacuum degree is ≤1*10 -3 Pa, melting temperature ≥ 600℃, until melted.

[0035] Step 3: Add In, Ti and Si in sequence to the material obtained in step 1, and then perform electromagnetic stirring. After stirring for 10 minutes, cool with the furnace to form a metal ingot; Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in sequence, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the addition of the above three elements is completed, start electromagnetic stirring. After stirring for 10 minutes, turn off the power of the vacuum furnace and cool with the furnace to form a metal ingot.

[0036] Step 4: Turn the metal ingot upside down and re-smelt it to obtain a uniform aluminum-based sacrificial anode material; take out the metal ingot, turn it upside down and put it back into the vacuum furnace for re-smelting, repeat this process 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

[0037] Step 5: After rolling, heat-treat the aluminum-based sacrificial anode material to obtain a high-temperature resistant sacrificial anode material. Step 5.1: Synchronously roll the aluminum-based sacrificial anode material obtained in step 4, with a total pressing amount of 50%, and a pressing amount of 5% required for each rolling; Step 5.2: Stress relief of the synchronously rolled material at 150°C for 24 hours; then perform aging treatment, first at 250°C for 1.5 hours, and then at 200°C for 15 hours, to finally obtain a high-temperature resistant sacrificial anode material.

[0038] The application of high temperature resistant sacrificial anode materials is used for surface corrosion inhibition of offshore oil and gas production equipment.

[0039] Embodiment 4: The chemical composition is 3.5wt% Zn, 0.06wt% In, 1.5wt% Mg, 0.07wt% Ti, 0.15wt% Si, and the balance Al. After smelting, the alloy is first aged at 250°C for 1.5 hours and then aged at 200°C for 15 hours. The high temperature resistant sacrificial anode material disclosed in this patent is obtained.

[0040] Embodiment 5: The chemical composition is 4wt% Zn, 0.06wt% In, 2wt% Mg, 0.07wt% Ti, 0.15wt% Si, and the balance Al. After smelting, the alloy is first aged at 250°C for 2 hours and then aged at 200°C for 20 hours. The high temperature resistant sacrificial anode material disclosed in this patent is obtained.

[0041] Embodiment 6: The chemical composition is 3wt% Zn, 0.05wt% In, 1wt% Mg, 0.07wt% Ti, 0.14wt% Si, and the balance Al. Smelting is performed, and after smelting evenly, aging is first performed at 250°C for 2 hours, and then aging is performed at 200°C for 10 hours. The high temperature resistant sacrificial anode material disclosed in this patent is obtained.

[0042] Comparative Example The high temperature resistant sacrificial anode material of the present invention is installed side by side with a zinc anode and an aluminum anode of the same volume on the same offshore oil and gas field equipment for testing.

[0043] like Figure 1 As shown, anode A is the high temperature resistant sacrificial anode material of the present invention, anode B is zinc anode, and anode C is aluminum anode. The figure is a graph of the open circuit potential test results of the above three anode materials; it can be seen intuitively from the figure that at any time, the voltage of anode A, i.e. the high temperature resistant sacrificial anode material of the present invention, in the open circuit potential test is higher than that of anodes B and C, indicating that the protection effect is better.

[0044] like Figure 2 As shown, at the same time, the corrosion morphology of each anode material before rust removal, from left to right, are respectively high temperature resistant sacrificial anode material, zinc anode and aluminum anode. It can be seen intuitively from the figure that the corrosion of anode A, i.e., the high temperature resistant sacrificial anode material of the present invention, is the most uniform, while the corrosion of anode B and anode C is uneven, indicating that the corrosion effect of anode A, i.e., the high temperature resistant sacrificial anode material of the present invention, is the best.

[0045] Table 1 Electrochemical performance results of various anodes in the target marine environment

[0046] It can be seen from the above table that the loss rate of A anode, i.e., the high temperature resistant sacrificial anode material of the present invention, is significantly lower than that of the zinc anode and the aluminum anode, indicating that the high temperature resistant sacrificial anode material of the present invention has a longer protection time and a better effect.

Claims

1. High temperature resistant sacrificial anode material, characterized in that: In terms of mass percentage, it is composed of the following raw material components: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance.

2. A method for preparing a high temperature resistant sacrificial anode material, characterized in that: The specific steps are as follows: Step 1: Weigh the following raw materials by mass percentage: 3-4wt% Zn, 0.05-0.06wt% In, 1-2wt% Mg, 0.07wt% Ti, 0.14-0.15wt% Si, and Al as the balance; Step 2: heating and melting the three materials of Al, Zn and Mg; Step 3: Add a certain amount of In, Ti, and Si to the material obtained in step 1 in sequence, and then perform electromagnetic stirring. After stirring for 10 minutes, cool with the furnace to form a metal ingot; Step 4: Turn the metal ingot upside down and re-smelt it to obtain a uniform aluminum-based sacrificial anode material; Step 5: The aluminum-based sacrificial anode material is rolled and then heat-treated to obtain a high-temperature resistant sacrificial anode material.

3. The method for preparing a high temperature resistant sacrificial anode material according to claim 2, characterized in that: The specific process of step 2 is as follows: Place the three materials of Al, Zn and Mg weighed in step 1 in a vacuum furnace for smelting, and the vacuum degree is ≤1*10 -3 Pa, melting temperature ≥ 600℃, until melted.

4. The method for preparing a high temperature resistant sacrificial anode material according to claim 3, characterized in that: The specific process of step 3 is as follows: Step 3.1: Add the In, Ti and Si weighed in step 1 to the molten material obtained in step 1 in sequence, and wait for 10 minutes after adding one element each time before adding the next element; Step 3.2: After the above three elements are added, start electromagnetic stirring. After stirring for 10 minutes, turn off the power of the vacuum furnace and cool it with the furnace to form a metal ingot.

5. The method for preparing a high temperature resistant sacrificial anode material according to claim 4, characterized in that: The specific process of step 4 is as follows: The metal ingot is taken out, turned upside down and put back into the vacuum furnace for re-smelting. The process is repeated 3-5 times to obtain a uniform aluminum-based sacrificial anode material.

6. The method for preparing a high temperature resistant sacrificial anode material according to claim 5, characterized in that: The specific process of step 5 is as follows: Step 5.1: synchronously rolling the aluminum-based sacrificial anode material obtained in step 4, with a total pressing amount of 40-60%, and a pressing amount of 5% required for each rolling; Step 5.2: The synchronously rolled material is subjected to stress relief at 150°C for 24 hours; then subjected to aging treatment, first at 250°C for 1-2 hours, and then at 200°C for 10-20 hours, to finally obtain a high temperature resistant sacrificial anode material.

7. The use of the high temperature resistant sacrificial anode material according to claim 1, characterized in that: Used for surface corrosion inhibition of offshore oil and gas production equipment.

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