Nickel-magnesium alloy, preparation method thereof and nickel-magnesium alloy product

Abstract

The invention relates to a nickel-magnesium alloy, a preparation method thereof and a nickel-magnesium alloy product. The preparation method of the nickel-magnesium alloy comprises the following steps that metal magnesium, metal nickel and fused salt are subjected to smelting treatment under the non-vacuum condition, and then forming treatment is conducted; the molten salt is prepared from the following components in parts by mass: 100 parts of KCl, 0 to 20 parts of MgCl2, 0 to 30 parts of KF, 0 to 20 parts of NaCl, 0.5 to 5 parts of CeCl3 and 0.5 to 5 parts of LaCl3. In the smelting process, under the non-vacuum condition, the fused salt with the specific components can cover the surface of magnesium melt, so that magnesium metal is not prone to volatilization and oxidation, the oxygen content and the inclusion content in the nickel-magnesium alloy are reduced, and the quality of the nickel-magnesium alloy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal alloys, and in particular to a nickel-magnesium alloy and a preparation method thereof, and a nickel-magnesium alloy product. Background Art

[0002] Inclusions in steel are a key issue that needs to be urgently addressed in the production of high-end steel materials. To improve the level of inclusion control in steel, it is necessary to find an effective solution to reduce the hazards of inclusions. Adding Mg to molten steel is an effective way to reduce the impurity content and the number of inclusions in steel. Mg has a strong affinity for O and S; adding Mg to molten steel has the effects of reducing the mass fraction of S and O in steel, denaturing inclusions, changing the structure, composition, and morphology of inclusions, reducing the number and size of inclusions, and improving the purity of steel.

[0003] Metal Mg has active chemical properties, with a boiling point of 1090°C and a vapor pressure of 2.238MPa at 1600°C. Metal Mg is volatile at steelmaking temperatures, and it is difficult for Mg to be added to molten steel to purify and desulfurize it. In addition, the Mg content is difficult to accurately control during the steelmaking process, and excessive Mg is added to the molten steel, introducing new inclusions. Currently, one of the ways to add Mg to molten steel is to add nickel-magnesium alloy (Ni-Mg alloy) to increase the melting point and boiling point of the Ni-Mg alloy and reduce Mg evaporation.

[0004] In the current preparation process of nickel-magnesium alloy, the melting temperature is high, Mg is volatile and easily oxidized, resulting in a large number of oxidized inclusions in the nickel-magnesium alloy. Therefore, the addition of nickel-magnesium alloy to molten steel cannot effectively purify the molten steel, and additional new inclusions are introduced, reducing the quality of the steel. The use of vacuum melting Ni-Mg alloy has low production efficiency and great safety hazards. Therefore, the safe and efficient preparation of a nickel-magnesium alloy with low impurity content and low inclusions is a current industry problem. Summary of the invention

[0005] Based on this, it is necessary to provide a nickel-magnesium alloy having a low oxygen impurity element content and a low inclusion content, a preparation method thereof, and a nickel-magnesium alloy product.

[0006] In a first aspect of the present application, a method for preparing a nickel-magnesium alloy is provided, comprising the following steps:

[0007] Metal magnesium, metal nickel and molten salt are smelted under non-vacuum conditions and then subjected to molding treatment; the molten salt comprises, by mass, 100 parts of KCl, 0-20 parts of MgCl2, 0-30 parts of KF, 0-20 parts of NaCl, 0.5-5 parts of CeCl3 and 0.5-5 parts of LaCl3.

[0008] In the above preparation method, metal magnesium, metal nickel and molten salt are smelted under non-vacuum conditions to provide a nickel-magnesium alloy with low oxygen content and low inclusion content. This process is safe and efficient. Among them, the above molten salt can cover the surface of the magnesium melt when it is melted, blocking the oxygen, carbon dioxide and other components in the environment from contacting the magnesium melt, reducing the generation of magnesium oxide inclusions; at the same time, it can further reduce the volatilization of magnesium. Furthermore, by controlling the molten salt with the above specific component ratio, the melting point of the molten salt can be increased to make it less volatile, so that during the melting process of metal nickel, the molten salt can be well covered on the surface of the magnesium melt, so that the magnesium melt and the nickel melt can be fully mixed.

[0009] In some embodiments, the molten salt covers the metallic magnesium during the smelting process.

[0010] In some embodiments, during the smelting process, the coverage thickness of the molten salt is ≥ 1 cm.

[0011] In some embodiments, the metallic magnesium accounts for 1 wt % to 30 wt % of the total mass of the metallic magnesium and the metallic nickel.

[0012] In some embodiments, the smelting is performed in a crucible; when the crucible is used for the smelting for the first time, before the smelting process is performed, the step of placing the molten salt melt in the crucible for pretreatment is also included.

[0013] In some embodiments, the crucible is a graphite crucible, a magnesia crucible, or a silicon carbide crucible.

[0014] In some embodiments, the smelting process is performed using a non-vacuum induction furnace.

[0015] In some embodiments, the molding process comprises the following steps:

[0016] In some embodiments, when the temperature of the mixed melt obtained after the smelting treatment is 1100° C. to 1200° C., the mixed melt is introduced into a mold for casting.

[0017] A second aspect of the present application provides a nickel-magnesium alloy, which is prepared by the preparation method described in the first aspect.

[0018] A second aspect of the present application provides a nickel-magnesium alloy product, comprising the nickel-magnesium alloy described in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application, and ordinary technicians in this field can obtain other drawings based on the disclosed drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the layered laying of metal nickel, metal magnesium and molten salt before smelting in an example of the present application.

[0021] Figure 2 This is the microstructure diagram of the nickel-magnesium alloy prepared in Example 1.

[0022] Figure 3 This is the microstructure diagram of the nickel-magnesium alloy prepared in Comparative Example 1.

[0023] Description of reference numerals:

[0024] 1. Metal nickel, 2. Metal magnesium, 3. Molten salt, 4. Crucible. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present invention, the present invention is described more comprehensively below. And preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] The weight of the relevant components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also indicate the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the description of the embodiments of the present invention, it is within the scope disclosed in the description of the embodiments of the present invention. Specifically, the weight described in the description of the embodiments of the present invention may be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0029] In one embodiment of the present application, a method for preparing a nickel-magnesium alloy is provided, comprising the following steps:

[0030] Metal magnesium, metal nickel and molten salt are smelted under non-vacuum conditions and then subjected to molding treatment; the molten salt comprises, by mass, 100 parts of KCl, 0-20 parts of MgCl2, 0-30 parts of KF, 0-20 parts of NaCl, 0.5-5 parts of CeCl3 and 0.5-5 parts of LaCl3.

[0031] In the above preparation method, metal magnesium, metal nickel and molten salt are smelted under non-vacuum conditions to provide a nickel-magnesium alloy with low oxygen content and low inclusion content. This process is safe and efficient. Among them, the above molten salt can cover the surface of the magnesium melt when it is melted, blocking the oxygen, carbon dioxide and other components in the environment from contacting the magnesium melt, reducing the generation of magnesium oxide inclusions; at the same time, it can further reduce the volatilization of magnesium. Furthermore, by controlling the molten salt with the above specific component ratio, the melting point of the molten salt can be increased to make it less volatile, so that during the melting process of metal nickel, the molten salt can be well covered on the surface of the magnesium melt, so that the magnesium melt and the nickel melt can be fully mixed.

[0032] As an example, in the molten salt, the mass fraction of MgCl2 can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. Further, in the molten salt, the mass fraction of MgCl2 can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass fraction of MgCl2 is 10 to 20.

[0033] As an example, in the molten salt, the mass fraction of KF can be 0, 1, 3, 5, 6, 8, 10, 12, 13, 14, 15, 16, 18, 20, 22, 25, 26, 28 or 30. Further, in the molten salt, the mass fraction of KF can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass fraction of KF is 10 to 20.

[0034] As an example, in the molten salt, the mass fraction of NaCl can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. Further, in the molten salt, the mass fraction of NaCl can be a range value consisting of any two of the above point values ​​as end values. Preferably, the mass fraction of NaCl is 10 to 20.

[0035] As an example, in the molten salt, the mass fraction of CeCl3 can be 0.5, 1, 2, 3, 4 or 5. Further, in the molten salt, the mass fraction of CeCl3 can be a range value consisting of any two of the above point values ​​as end values.

[0036] As an example, in the molten salt, the mass fraction of LaCl3 can be 0.5, 1, 2, 3, 4 or 5. Further, in the molten salt, the mass fraction of LaCl3 can be a range value consisting of any two of the above point values ​​as end values.

[0037] In some embodiments, the molten salt covers the magnesium melt during the smelting process. It is understood that since the density of the molten salt is lower than that of the magnesium melt, the molten salt covers the surface of the magnesium melt during the smelting process, thereby blocking the contact between magnesium and components such as oxygen, and reducing the volatilization and oxidative combustion of magnesium.

[0038] In some embodiments, the above preparation method further includes: before the smelting process, laying molten salt on the upper surface of the magnesium metal.

[0039] In some embodiments, the preparation method further includes: before the smelting process, first placing metal magnesium and metal nickel at the bottom, and then laying molten salt on the upper surface of the metal magnesium and metal nickel. The metal magnesium and metal nickel can be placed at the bottom as a mixture; or they can be placed at the bottom in layers, that is, the metal magnesium can be laid at the bottom first, then the metal nickel can be laid on the upper surface of the metal magnesium, and finally the molten salt can be laid on the upper surface of the metal nickel. Alternatively, the metal nickel can be laid at the bottom first, then the metal magnesium can be laid on the upper surface of the metal nickel, and finally the molten salt can be laid on the upper surface of the metal magnesium.

[0040] like Figure 1 As shown, in a specific example, metal nickel 1 is first placed at the bottom of a crucible 4 , and then metal magnesium 2 is laid on the upper surface of the metal nickel 1 , and then molten salt 3 is laid on the upper surface of the metal magnesium 2 .

[0041] In some embodiments, during the smelting process, the coverage thickness of the molten salt is ≥ 1 cm. As an example, the coverage thickness of the molten salt can be 1 cm, 1.5 cm, 2 cm, 2.5 cm or 3 cm; or any other thickness value within the above range. Further, on the basis of improving the coverage performance, in order to reduce the cost, the coverage thickness of the molten salt is 1 cm to 3 cm.

[0042] In some embodiments, the metallic magnesium accounts for 1 wt % to 30 wt % of the total mass of the metallic magnesium and the metallic nickel.

[0043] In some embodiments, the smelting is performed in a crucible.

[0044] In some embodiments, the crucible is a graphite crucible, a magnesia crucible or a silicon carbide crucible, preferably a graphite crucible.

[0045] In some embodiments, when the crucible is used for smelting for the first time, before the smelting process, the process further includes placing the molten salt melt in the crucible for pretreatment.

[0046] In some embodiments, the pretreatment temperature is 900°C to 1200°C.

[0047] In some embodiments, the pretreatment time is 2 hours to 5 hours. Placing the molten salt melt in the crucible for 2 hours to 5 hours can allow the molten salt components to exchange substances with the crucible, and the molten salt components enter the crucible, so that the components in the crucible are saturated, reducing crucible loss; reducing the pollution of impurities brought by the crucible to the alloy, and improving the quality of the alloy product.

[0048] In some embodiments, the mass ratio of magnesium metal to molten salt is 1:(0.2-1). The mass ratio of magnesium metal to molten salt can be 1:0.2, 1:0.3, 1:0.5, 1:0.8 or 1:1; or any other ratio within the above range.

[0049] In some embodiments, the crucible is a graphite crucible, a magnesia crucible or a silicon carbide crucible, preferably a graphite crucible.

[0050] In some embodiments, the crucible is placed in a non-vacuum induction furnace to perform the above melting step.

[0051] In some embodiments, the smelting step includes: first adding metal magnesium and molten salt into a crucible for a first smelting; then adding metal nickel for a second smelting. Further, first placing metal magnesium at the bottom of the crucible, and then laying molten salt on the upper surface of the metal magnesium.

[0052] In some embodiments, the temperature control method of the first smelting includes: heating under the conditions that the power of the non-vacuum induction furnace is set to 50kW~60kW and the induction frequency is set to 1000Hz~1300H, and the temperature is raised from room temperature to 650℃~750℃; then, heating is continued for 5min~15min under the conditions that the power of the non-vacuum induction furnace is set to 50kW~75kW and the induction frequency is set to 1100Hz~1500H.

[0053] In some embodiments, the temperature control method of the second smelting includes: continuing heating under the conditions that the power of the non-vacuum induction furnace is set to 45kW~60kW and the induction frequency is 1100Hz~1300Hz, so that the temperature rises to 1100℃~1300℃; then continuing heating for 10min~20min under the conditions that the power of the non-vacuum induction furnace is set to 65kW~80kW and the induction frequency is 1300Hz~1500Hz.

[0054] In some embodiments, the smelting step includes: adding metal magnesium, metal nickel and molten salt into a crucible to perform a third smelting.

[0055] In some embodiments, the temperature control method of the third smelting includes: heating under the conditions of a non-vacuum induction furnace power of 50kW~60kW and an induction frequency of 800Hz~1100H to raise the temperature from room temperature to 1100℃~1300℃; and then continuing heating for 15min~25min under the conditions of a non-vacuum induction furnace power of 70kW~80kW and an induction frequency of 1200Hz~1500H.

[0056] In some embodiments, the molding process includes the following steps:

[0057] When the temperature of the mixed melt obtained after the smelting treatment is 1100-1200°C, the mixed melt is introduced into a mold for casting.

[0058] In some embodiments, the following steps are further included before casting:

[0059] The mixed melt is subjected to slag removal treatment, which can remove excess molten salt and other impurity components on the surface and improve the purity of the nickel-magnesium alloy.

[0060] It is understandable that slag removal may not be performed during the preparation of the nickel-magnesium alloy, because after the subsequent casting step, the molten salt components will float on the surface and will not enter the content of the casting body, and the molten salt impurity components can be easily removed.

[0061] In another embodiment of the present application, a nickel-magnesium alloy obtained by the above preparation method is provided.

[0062] In some embodiments, the nickel-magnesium alloy includes the following elemental components by weight percentage:

[0063] Mg 7.5wt%~30wt%, Ni 70wt%~98wt% and O 0~0.05wt%.

[0064] In some embodiments, in the nickel-magnesium-nickel-magnesium-gold, the mass percentage of O is 0.0025wt% to 0.0047wt%. The lower the oxygen content in the nickel-magnesium alloy, the more conducive it is for the Mg element to remove O and S from the molten steel, thereby improving the performance of the steel material.

[0065] In some embodiments, the nickel-magnesium alloy further comprises, by weight percentage, 0.003wt% to 0.01wt% of C. Furthermore, in the nickel-magnesium alloy, the mass fraction of C is 0.003wt% to 0.0071%.

[0066] In some embodiments, the nickel-magnesium alloy further comprises 0.002 wt % to 0.07 wt % of Mn, calculated by mass percentage.

[0067] In some embodiments, the nickel-magnesium alloy further comprises 0.004wt% to 0.001wt% Si, by weight percentage. Preferably, the mass fraction of Si in the nickel-magnesium alloy is 0.0045wt% to 0.0083wt%.

[0068] In nickel-magnesium alloys, the above-mentioned C, Mn, Si and O are harmful elements. Excessive content will affect the desulfurization effect of nickel-magnesium alloys when used as desulfurizers, thereby reducing the quality of steel.

[0069] In some embodiments, the nickel-magnesium alloy contains inclusions with an area ratio of less than or equal to 3%. Controlling the inclusion content in the nickel-magnesium alloy can inhibit the nickel-magnesium alloy desulfurizer from bringing new impurities to the steel and reducing the performance of the steel.

[0070] Furthermore, the proportion of inclusions in the above-mentioned nickel-magnesium alloy is 0.5%~2.5%.

[0071] In another embodiment of the present application, a nickel-magnesium alloy product is provided, and the nickel-magnesium alloy product includes the above-mentioned nickel-magnesium alloy.

[0072] In some embodiments, the nickel-magnesium alloy article may be a desulfurization agent.

[0073] In order to make the purpose, technical solutions and advantages of the present invention more concise and clear, the present invention is described with the following specific embodiments, but the present invention is by no means limited to these embodiments. The embodiments described below are only preferred embodiments of the present invention, which can be used to describe the present invention and cannot be understood as limiting the scope of the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0074] In order to better illustrate the present invention, the present invention is further described below in conjunction with the embodiments. The following are specific embodiments.

[0075] The metal magnesium used in each embodiment and comparative example of the present application is a commercially available industrial magnesium ingot, and the metal nickel is a commercially available industrial nickel ingot.

[0076] Example 1

[0077] This embodiment uses a non-vacuum induction furnace for smelting. Among them, the graphite crucible in the non-vacuum induction furnace is used for the first smelting of metal magnesium, metal nickel and molten salt. The preparation method of nickel-magnesium alloy is as follows:

[0078] Graphite crucible pretreatment:

[0079] Add molten salt to a graphite crucible to cover 3 / 4 of the crucible. The molten salt is 100 parts of KCl, 10 parts of MgCl2, 5 parts of CeCl3 and 5 parts of LaCl3. The melting temperature is 900°C and the time is 2 hours.

[0080] Melting steps:

[0081] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 15wt% and a nickel content of 85wt%; and molten salt, which is 100 parts of KCl, 10 parts of MgCl2, 0.5 parts of CeCl3 and 0.5 parts of LaCl3 by mass. The mass ratio of the magnesium ingot to the molten salt is 1:1.

[0082] (2) First place the magnesium ingot at the bottom of the crucible, then spread the molten salt on the upper surface of the magnesium ingot. The crucible is then placed in a non-vacuum induction furnace.

[0083] (3) Melting magnesium ingot: Set the power of the non-vacuum induction furnace to 40kW, the frequency of the medium frequency furnace to 900Hz, and start heating; during the heating process, the metal magnesium gradually melts. When the temperature reaches 670℃, continue heating and smelting for 5min; the metal magnesium is completely melted; the thickness of the molten salt covering the metal magnesium melt is 3cm.

[0084] (4) Add nickel ingot: Add nickel metal to the graphite crucible; set the non-vacuum induction furnace power to 45kW, the induction frequency to 1100Hz, and continue heating. When the temperature rises to 1200℃, increase the non-vacuum induction furnace power to 65kW and the induction frequency to 1300Hz, and continue heating and melting for 10 minutes.

[0085] (5) Casting: After step (4) is completed, the power of the non-vacuum induction furnace is set to 45 kW and the induction frequency is set to 1100 Hz. Under this condition, the temperature of the mixed melt is reduced to 1150°C. The mixed melt is then led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0086] Example 2

[0087] This embodiment uses a non-vacuum induction furnace for smelting. The graphite crucible in the non-vacuum induction furnace is not used for smelting metal magnesium, metal nickel and molten salt for the first time. The smelting steps are as follows:

[0088] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 15wt% and a nickel content of 85wt%. Weigh molten salts respectively. The molten salts are 100 parts of KCl, 10 parts of MgCl2, 0.5 parts of CeCl3 and 0.5 parts of LaCl3 by mass; the mass ratio of magnesium ingot to molten salt is 1:0.7.

[0089] (2) Third smelting: Mix the above magnesium ingot and nickel ingot evenly, and then place them at the bottom of the crucible; spread the molten salt on the upper surface of the magnesium ingot and the nickel ingot. Set the non-vacuum induction furnace power to 50kW and the induction frequency to 1200Hz for heating and smelting. When the temperature rises to 1200℃, set the non-vacuum induction furnace power to 70kW and the induction frequency to 1400Hz, and continue smelting for 10 minutes; the covering thickness of the molten salt is 2cm.

[0090] (3) Casting: After step (2) is completed, the power of the non-vacuum induction furnace is set to 40 kW and the induction frequency is set to 1000 Hz. Under this condition, the temperature of the mixed melt is reduced to 1200°C. The mixed melt is then led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0091] Example 3

[0092] This embodiment uses a non-vacuum induction furnace for smelting. The graphite crucible in the non-vacuum induction furnace is used for smelting metal magnesium, metal nickel and molten salt for the first time. The preparation steps are as follows:

[0093] Graphite crucible pretreatment:

[0094] Add molten salt to a graphite crucible to cover 3 / 4 of the crucible. The molten salt is 100 parts of KCl, 10 parts of MgCl2, 5 parts of CeCl3 and 5 parts of LaCl3. The melting temperature is 1200℃ and the time is 5h.

[0095] Melting steps:

[0096] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 20wt% and a nickel content of 80wt%. Weigh molten salts respectively. The molten salts are 100 parts of KCl, 5 parts of NaCl, 30 parts of KF, 5 parts of MgCl2, 0.5 parts of CeCl3, and 5 parts of LaCl3 by mass. The mass ratio of magnesium ingot to molten salt is 1:0.3.

[0097] (2) First place the magnesium ingot at the bottom of the crucible, then spread the molten salt on the upper surface of the magnesium ingot. The crucible is then placed in a non-vacuum induction furnace.

[0098] (3) Melting magnesium ingot: Set the power of the non-vacuum induction furnace to 50kW, the frequency of the medium frequency furnace to 1100Hz, and start heating; during the heating process, the metal magnesium gradually melts. When the temperature reaches 670℃, continue heating and smelting for 5min; the metal magnesium is completely melted; the thickness of the molten salt covering the metal magnesium melt is 1cm.

[0099] (4) Add nickel ingot: Add nickel metal to the graphite crucible; set the non-vacuum induction furnace power to 45kW, the induction frequency to 1100Hz, and continue heating. When the temperature rises to 1200℃, increase the non-vacuum induction furnace power to 65kW and the induction frequency to 1300Hz, and continue heating and melting for 10 minutes.

[0100] (5) Casting: After step (4) is completed, the power of the non-vacuum induction furnace is set to 45 kW and the induction frequency is set to 1100 Hz. Under this condition, the temperature of the mixed melt is reduced to 1200°C. The mixed melt is then led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0101] Example 4

[0102] This embodiment uses a non-vacuum induction furnace for smelting. The graphite crucible in the non-vacuum induction furnace is not used for smelting metal magnesium, metal nickel and molten salt for the first time. The smelting steps are as follows:

[0103] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 20wt% and a nickel content of 80wt%. Weigh molten salts respectively. The molten salts are 100 parts of KCl, 10 parts of NaCl, 15 parts of KF, 5 parts of MgCl2, 3 parts of CeCl3, and 5 parts of LaCl3 by mass; the mass ratio of magnesium ingot to molten salt is 1:0.35.

[0104] (2) Third smelting: Mix the above magnesium ingot and nickel ingot evenly, and then place them at the bottom of the crucible; spread the molten salt on the upper surface of the magnesium ingot and the nickel ingot. The molten salt covers the magnesium melt with a thickness of 1.5 cm. Set the non-vacuum induction furnace power to 50 kW and the induction frequency to 1200 Hz for heating and smelting. The magnesium metal is completely melted; the molten salt covers the magnesium melt with a thickness of 2 cm. When the temperature rises to 1200°C, set the non-vacuum induction furnace power to 70 kW and the induction frequency to 1400 Hz, and continue smelting for 10 minutes.

[0105] (3) Casting: After step (2) is completed, the power of the non-vacuum induction furnace is set to 30 kW and the induction frequency is set to 1000 Hz. Under this condition, the temperature of the mixed melt is reduced to 1200°C. The mixed melt is then led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0106] Example 5

[0107] This embodiment uses a non-vacuum induction furnace for smelting. The graphite crucible in the non-vacuum induction furnace is not used for smelting metal magnesium, metal nickel and molten salt for the first time. The smelting steps are as follows:

[0108] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 8wt% and a nickel content of 92wt%. Weigh the molten salt separately. The molten salt includes 100 parts of KCl, 20 parts of MgCl2, 30 parts of NaCl, 5 parts of CeCl3 and 3 parts of LaCl3 by mass; the mass ratio of magnesium ingot to molten salt is 1:1.

[0109] (2) Third smelting: Mix the above magnesium ingot and nickel ingot evenly, and then place them at the bottom of the crucible; spread the molten salt on the upper surface of the magnesium ingot and the nickel ingot. Set the non-vacuum induction furnace power to 50kW and the induction frequency to 1200Hz for heating and smelting; the thickness of the molten salt covering the metal magnesium melt is 2cm. When the temperature rises to 1200℃, set the non-vacuum induction furnace power to 70kW and the induction frequency to 1400Hz, and continue smelting for 10 minutes.

[0110] (3) Casting: After step (2) is completed, the power of the non-vacuum induction furnace is set to 40 kW and the induction frequency is set to 1000 Hz. Under this condition, it is maintained for 5 minutes; the temperature of the mixed melt is reduced to 1150°C. Then the mixed melt is led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0111] Example 6

[0112] This embodiment uses a non-vacuum induction furnace for smelting. The graphite crucible in the non-vacuum induction furnace is not used for smelting metal magnesium, metal nickel and molten salt for the first time. The smelting steps are as follows:

[0113] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots with a magnesium content of 30wt% and a nickel content of 70wt%. Weigh molten salts respectively. The molten salts are 100 parts of KCl, 20 parts of NaCl, 3 parts of CeCl3 and 2 parts of LaCl3 by mass; the mass ratio of magnesium ingot to molten salt is 1:0.2.

[0114] (2) Third smelting: Mix the above magnesium ingot and nickel ingot evenly, and then place them at the bottom of the crucible; spread the molten salt on the upper surface of the magnesium ingot and the nickel ingot. Set the non-vacuum induction furnace power to 50kW and the induction frequency to 1200Hz for heating and smelting; the thickness of the molten salt covering the metal magnesium melt is 1cm. When the temperature rises to 1200℃, set the non-vacuum induction furnace power to 70kW and the induction frequency to 1400Hz, and continue smelting for 10 minutes.

[0115] (3) Casting: After step (2) is completed, the power of the non-vacuum induction furnace is set to 30 kW and the induction frequency is set to 1000 Hz. Under this condition, it is maintained for 5 minutes; the temperature of the mixed melt is reduced to 1180°C. Then the mixed melt is led out and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0116] Example 7

[0117] The preparation method of this embodiment is basically the same as the preparation method of Example 2, the only difference being that the ratio of the molten salt is different. The molten salt of this embodiment, by mass, includes 100 parts of KCl, 20 parts of KF, 10 parts of MgCl2, 5 parts of CeCl3 and 5 parts of LaCl3.

[0118] Example 8

[0119] The preparation method of this embodiment is basically the same as the preparation method of Example 7, the only difference being that the ratio of the molten salt is different. The molten salt of this embodiment, by mass, includes 100 parts of KCl, 20 parts of KF, 10 parts of MgCl2, 0.5 parts of CeCl3 and 0.5 parts of LaCl3.

[0120] Comparative Example 1

[0121] This embodiment uses a non-vacuum induction furnace for smelting. The smelting steps are as follows:

[0122] (1) Weigh appropriate amounts of magnesium ingots and nickel ingots according to a magnesium content of 20wt% and a nickel content of 80wt%.

[0123] (2) Add magnesium ingot and nickel ingot into the graphite crucible in the non-vacuum induction furnace, introduce Ar and SF6; add a covering agent, wherein the covering agent is composed of 100 parts of NaCl and 30 parts of KCl; wherein the mass ratio of magnesium ingot to molten salt is 1:0.3, and the covering thickness is 2 cm. Set the non-vacuum induction furnace power to 50 kW and the induction frequency to 1200 Hz for heating and smelting. When the temperature rises to 1200 ° C, set the non-vacuum induction furnace power to 70 kW and the induction frequency to 1400 Hz, and continue smelting for 10 minutes.

[0124] (3) Casting: After step (2) is completed, the power of the non-vacuum induction furnace is set to 40 kW and the induction frequency is set to 1000 Hz. Under this condition, it is maintained for 5 minutes. Then the mixed melt is discharged and introduced into a mold for casting; then cooled to obtain a nickel-magnesium alloy.

[0125] The raw material components and proportions in each embodiment and comparative example are shown in Table 1.

[0126] Table 1

[0127]

[0128] Performance Test:

[0129] Elemental analysis: measured using ICP.

[0130] Inclusion ratio: Tested according to the method specified in GB / T 18876.1-2002. For each sample, two samples were cut from the diagonal of the ingot, one near the edge and the other near the center. Five photos were taken with a metallographic microscope at a magnification of 500 times, for a total of 10 photos. The metallographic analysis software (ImageJ) was used to automatically analyze the area ratio of inclusions in the field of view, and the average area ratio of inclusions in the 10 photos was taken to obtain the area ratio of inclusions in the nickel-magnesium alloy.

[0131] The element composition and inclusion ratio of the nickel-magnesium alloy prepared in each embodiment and comparative example are shown in Table 2.

[0132] Table 2

[0133]

[0134] As can be seen from Table 2, Examples 1 to 8 use the preparation method of the present application to prepare nickel-magnesium alloys, and the obtained nickel-magnesium alloys have a low content of oxygen impurity elements; the proportion of inclusions in the nickel-magnesium alloy is also relatively small. Figure 2 As shown, Figure 2 This is the microstructure diagram of the nickel-magnesium alloy prepared in Example 1, and the inclusions in the nickel-magnesium alloy are very small.

[0135] Comparative Example 1 prepared a nickel-magnesium alloy under non-vacuum conditions, using only two components of molten salt, NaCl and KCl. The oxygen content of the prepared nickel-magnesium alloy was as high as 0.31%; the inclusion ratio was also as high as 6.9%. Figure 3 It can be seen that in the nickel-magnesium alloy prepared in Comparative Example 1, the area ratio of inclusions is significantly greater than the area ratio of inclusions in Example 1.

[0136] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for preparing a nickel-magnesium alloy, characterized in that: The steps include: Metal magnesium, metal nickel and molten salt are smelted under non-vacuum conditions and then subjected to molding treatment; the molten salt comprises, by mass, 100 parts of KCl, 0-20 parts of MgCl2, 0-30 parts of KF, 0-20 parts of NaCl, 0.5-5 parts of CeCl3 and 0.5-5 parts of LaCl3.

2. The preparation method according to claim 1, characterized in that The molten salt covers the metallic magnesium during the smelting process.

3. The preparation method according to claim 2, characterized in that: During the smelting process, the covering thickness of the molten salt is ≥1 cm.

4. The preparation method according to claim 1, characterized in that: The metallic magnesium accounts for 1 wt % to 30 wt % of the total mass of the metallic magnesium and the metallic nickel.

5. The preparation method according to claim 3, characterized in that: The smelting is carried out in a crucible; when the crucible is used for the smelting for the first time, before the smelting process, the step of placing the molten salt melt in the crucible for pretreatment is also included.

6. The preparation method according to claim 5, characterized in that: The crucible is a graphite crucible, a magnesia crucible or a silicon carbide crucible.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The smelting process is carried out in a non-vacuum induction furnace.

8. The preparation method according to any one of claims 1 to 6, characterized in that: The molding process comprises the following steps: When the temperature of the mixed melt obtained after the smelting treatment is 1100° C. to 1200° C., the mixed melt is introduced into a mold for casting.

9. A nickel-magnesium alloy, characterized in that: The method is prepared by the preparation method according to any one of claims 1 to 8.

10. A nickel-magnesium alloy product, characterized in that: Comprising the nickel-magnesium alloy as described in claim 9.

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