Method for preparing low-boron spheroidizing agent

Abstract

To provide a method for preparing a low-boron spheroidizing agent.SOLUTION: Disclosed is a method for preparing a low-boron spheroidizing agent, which comprises: a step 1 of mixing various raw materials at a fixed ratio, where the raw materials required include magnesium ingots, metallic calcium, ferrosilicon, iron scrap, rare earth, aluminum, and the like, and mixing the mixed materials by an automatic batching system; a step 2 of transporting the prepared raw materials into a smelting furnace by a conveyance system for smelting; and a step 3 of continuously measuring and monitoring a temperature in the furnace in the process of smelting the raw materials in the smelting furnace. By adopting the method for preparing the spheroidizing agent of the present application, a low-boron spheroidizing agent having a boron content of 40 ppm or less can be produced.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of spheronizing agents, and in particular to a method for preparing a low-boron spheronizing agent. [Background technology]

[0002] A spheroidizing agent is a specific metal or alloy that is added to molten iron to obtain spheroidal graphite cast iron. The one commonly used in China is ferrosilicon rare earth magnesium spheroidizing agent. The preparation process of the spheroidizing agent includes thermal remelting, low silicon granulation and so on. According to the effect of various elements in the spheroidizing agent on spheroidization, the rational allocation, optimization of the production process, and improvement of the quality of ductile iron are the tasks that casting engineers are constantly researching. With the increasing requirements of customers for product quality, the spheroidizing agents currently on the market have a high boron content and cannot meet the preparation requirements of special ductile iron. The boron content of the spheroidizing agents currently on the market is generally above 60 ppm, which cannot meet the preparation requirements of special ductile iron. Trace elements in a spheroidizing agent, for example, boron in the agent, have a significant effect on the quality of spheroidization, including the effect on graphite and matrix structure, so it is necessary to control the boron content in the agent, and preparing a spheroidizing agent with a boron content of 50 ppm or less has become a technical challenge. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of this, the present invention provides a method for preparing a low-boron spheroidizing agent to solve the problem that existing techniques are unable to prepare a spheroidizing agent having a boron content of 50 ppm or less. [Means for solving the problem]

[0004] In order to solve the above technical problems, the present invention provides a method for preparing a low boron spheroidizing agent, which includes the following components: A method for preparing a low boron spheroidizing agent, comprising the steps of: Step 1, mixing various raw materials in a certain ratio, where the raw materials required include magnesium ingot, calcium metal, ferrosilicon, iron scrap, rare earth and aluminum, which are blended and mixed by an automatic batching system; Step 2 transports the blended raw materials into a smelting furnace by a conveying system and smelts them; Step 3: continuously measuring and monitoring the temperature in the smelting furnace during the process of smelting the raw materials in the smelting furnace; After smelting is complete, step 4 is to cast and make ingots. Step 5: After the ingot is made, the ingot is cooled in a timely manner using a closed type oxygen-free rapid condensation device to reduce the ineffective magnesium in the metal ingot and make the product quality more stable and controllable. Step 6: After the metal ingot is cooled, it is crushed into a certain particle size using a crushing device, and the particle size can be crushed according to customer needs. Step 7: After the grinding is completed, the product is inspected to ensure its quality. After the inspection is completed, step 8 includes storing the products in batches until use.

[0005] Furthermore, in order to prevent a large amount of boron from being contained in the smelting furnace, the preparation method of the smelting furnace is as follows. (1) First, the smelting furnace material and the adhesive are mixed; (2) Construct the furnace lining; (3) Accelerate hardening with carbon dioxide for 15 minutes. (4) Dry the furnace body for 6 to 8 hours.

[0006] Furthermore, the material of the smelting furnace is a neutral material, and the pH value of the neutral material is 7.

[0007] Furthermore, the elements contained in the spheroidizing agent prepared using the above-mentioned various raw materials include silicon, magnesium, rare earth elements, calcium, aluminum, and boron.

[0008] Furthermore, the number of parts of each raw material contained in the spheroidizing agent is 40-50 parts of silicon, 5-8 parts of magnesium, 0.5-2 parts of rare earths, 0.8-2 parts of calcium, 0.3-1 part of aluminum, and <40 ppm of boron.

[0009] Furthermore, the number of parts of each raw material contained in the spheroidizing agent is as follows: silicon 40 parts, magnesium 5 parts, rare earth 0.5 parts, calcium 0.8 parts, aluminum 0.3 parts, and boron <40 ppm parts.

[0010] Furthermore, the number of parts of each raw material contained in the spheroidizing agent is as follows: silicon 50 parts, magnesium 8 parts, rare earths 2 parts, calcium 2 parts, aluminum 1 part, and boron <40 ppm parts. Effect of the Invention

[0011] The above-described configuration of the present invention provides at least the following beneficial effects. By adopting the manufacturing method of the spheroidizing agent of the present application, it is possible to manufacture a low-boron spheroidizing agent with a boron content of 40 ppm or less. After many years of research, it has been found that the manufacturing raw materials of the spheroidizing agent do not affect the increase of the boron content, but in the spheroidizing process, the current spheroidizing furnace uses a mixture of normal materials (non-neutral materials) and boric acid adhesive, so the boron element contained in the furnace lining is mixed into the raw materials and refined together during the process of spheroidizing agent raw materials being smelted using a normal spheroidizing furnace, which increases the boron content in the spheroidizing agent. In the present invention, the smelting furnace material is improved, that is, the smelting furnace material is changed to a neutral material with a pH value of 7, and this smelting furnace material is mixed with an adhesive containing boric acid to cause a chemical reaction, thereby reducing the boron element in the adhesive containing boric acid. Therefore, when the raw material for the spheroidizing agent is later smelted again using a smelting furnace, the boron content in the raw material will not increase. Therefore, by changing the smelting furnace material and then producing a spheroidizing agent using the process of the present application, it is possible to produce a low-boron spheroidizing agent with a boron content of 40 ppm or less. [Brief description of the drawings]

[0012] [Figure 1] 1 is a metallographic image of a low boron nodularizer produced according to the present invention in a clamping application, with a boron content of 0.004%, in an uncorroded state. [Diagram 2] 1 is a metallographic image of a low boron spheroidizing agent produced according to the present invention in a clamping application, with a boron content of 0.007%, in an uncorroded state. [Diagram 3] 1 is a metallographic image of a low boron nodularizer produced according to the present invention in a clamping application, with a boron content of 0.004%, in a corroded condition. [Figure 4] 1 is a metallographic image of a low boron nodularizer produced according to the present invention in a clamping application, with a boron content of 0.007%, in a corroded condition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The technical configurations of the embodiments of the present invention will be described below clearly and completely in conjunction with the drawings of the embodiments of the present invention. Those skilled in the art should understand that the embodiments described below are only a part of the embodiments of the present disclosure, and are not all of the embodiments. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

[0014] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description in conjunction with the drawings in which several embodiments of the present invention are illustrated, by way of example and not limitation, in which like or corresponding symbols represent like or corresponding parts. EXAMPLES

[0015] Example 1 of the method for producing a low boron spheroidizing agent provided by the present invention is as follows. A method for preparing a low boron spheroidizing agent, comprising the steps of: Step 1: mixing various raw materials in a certain ratio, where the raw materials required include magnesium ingot, metallic calcium, ferrosilicon, iron scrap, rare earth, aluminum, etc., and blending and mixing them by an automatic batching system; Step 2: transporting the prepared raw materials to a smelting furnace by a conveying system and smelting the raw materials; Step 3: continuously measuring and monitoring the temperature in the smelting furnace during the process of smelting the raw materials in the smelting furnace; After smelting is complete, step 4 is to cast and make ingots. Step 5: After the ingot casting is completed, the ingot is cooled in a timely manner using a closed type oxygen-free rapid condensation device to reduce the ineffective magnesium in the metal ingot, making the product quality more stable and easier to control; Step 6: After the metal ingot is cooled, it is crushed into a certain particle size using crushing equipment, specifically, it can be crushed into a specific particle size according to customer needs; Step 7: After the grinding is completed, the product is inspected to ensure its quality. After the inspection is completed, step 8 includes storing the products in batches until use.

[0016] Furthermore, in order to prevent a large amount of boron from being contained in the smelting furnace, the preparation method of the smelting furnace is as follows. (1) First, the smelting furnace material and the adhesive are mixed; (2) constructing a lining for the furnace; (3) Accelerate hardening with carbon dioxide for 15 minutes. (4) Dry the furnace body for 6 to 8 hours.

[0017] The material of the smelting furnace is neutral material, and the pH value of neutral material is 7.

[0018] The elements contained in the spheroidizing agent prepared using the above-mentioned various raw materials include silicon, magnesium, rare earth elements, calcium, aluminum and boron.

[0019] The number of parts of each ingredient contained in the spheroidizing agent is as follows: silicon 40 parts, magnesium 5 parts, rare earth 0.5 parts, calcium 0.8 parts, aluminum 0.3 parts, boron <40 ppm parts.

[0020] The low boron spheroidizing agent produced using the above-mentioned production method and raw materials has the following uses in clamps: The metallographic image of the clamp in an uncorroded state with a boron content of 0.004% is shown in Figure 1. The metallographic image of the uncorroded clamp with a boron content of 0.007% is shown in Figure 2. The metallographic image of the corroded clamp with a boron content of 0.004% is shown in Figure 3. A metallographic image of the corroded clamp with a boron content of 0.007% is shown in Figure 4.

[0021] Furthermore, Table 1 below is an analysis table of graphite morphology of ductile iron treated with spheroidizing agents of different boron contents.

[0022] [Table 1]

[0023] Table 2 below shows the tensile strength of ductile iron treated with spheroidizing agents of different boron contents.

[0024] [Table 2]

[0025] Table 3 below shows the elongation of ductile iron treated with spheroidizing agents of different boron contents.

[0026] [Table 3]

[0027] Table 4 below shows the hardness of ductile iron treated with spheroidizing agents of different boron contents.

[0028] [Table 4]

[0029] Table 5 below shows the impact energy of ductile iron treated with spheroidizing agents of different boron contents.

[0030] [Table 5]

[0031] By adopting the manufacturing method and raw material blending ratio of the present invention, it is possible to manufacture a low-boron spheroidizing agent with a boron content of 40 ppm or less, and the use of this low-boron spheroidizing agent has produced favorable results in practical applications, while also meeting market needs. EXAMPLES

[0032] Example 2 of the method for producing a low boron spheroidizing agent provided by the present invention is as follows. The parts of each ingredient contained in the spheroidizing agent are: silicon 50 parts, magnesium 8 parts, rare earths 2 parts, calcium 2 parts, aluminum 1 part, boron <40 ppm parts. EXAMPLES

[0033] Example 3 of the method for producing a low boron spheroidizing agent provided by the present invention is as follows. The proportions of each raw material contained in the spheroidizing agent are 48 parts silicon, 7 parts magnesium, 1 part rare earth, 1 part calcium, 0.8 parts aluminum, and <40 ppm boron.

[0034] The above is a preferred embodiment of the present invention. Although the present invention has been described in detail above by combining the drawings and examples, those skilled in the art can understand that various specific parameters of the above embodiment can be changed to form multiple specific examples without departing from the spirit of the present invention, and all of them are within the common variation range of the present invention, so a detailed description will not be given here.

Claims

1. Step 1, mixing various raw materials in a certain ratio, where the raw materials required include magnesium ingot, calcium metal, ferrosilicon, iron scrap, rare earth and aluminum, which are blended and mixed by an automatic batching system; Step 2: transporting the blended raw materials into a smelting furnace by a conveying system and smelting the raw materials; Step 3: continuously measuring and monitoring the temperature in the smelting furnace during the process of smelting the raw material in the smelting furnace; After smelting is completed, step 4 is to cast and make ingots; Step 5: After the ingot is made, the ingot is cooled in a timely manner using a closed type oxygen-free rapid condensation device to reduce the ineffective magnesium in the ingot and make the product quality more stable and controllable; Step 6: After the metal ingot is cooled, it is crushed into a certain particle size using a crushing device, and the particle size can be crushed according to customer needs; Step 7: After the grinding is completed, inspect the product to ensure its quality; A method for preparing a low boron spheroidizing agent, comprising step 8 of storing the product in batches until use after the inspection is completed.

2. In order to prevent a large amount of boron from being contained in the smelting furnace, the method for preparing the smelting furnace includes: (1) First, the smelting furnace material and the adhesive are mixed; (2) constructing a lining for the furnace; (3) Accelerate curing with carbon dioxide for 15 minutes; (4) Dry the furnace body for 6 to 8 hours; 2. The method for preparing a low boron spheroidizing agent according to claim 1,

3. 3. The method for preparing a low boron spheroidizing agent according to claim 2, wherein the material of the smelting furnace is a neutral material, and the pH value of the neutral material is 7.

4. 2. The method for preparing a low boron spheroidizing agent according to claim 1, characterized in that the elements contained in the spheroidizing agent prepared using the various raw materials include silicon, magnesium, rare earth elements, calcium, aluminum and boron.

5. The method for preparing a low-boron spheroidizing agent according to claim 4, characterized in that the number of parts of each raw material contained in the spheroidizing agent is 40 to 50 parts of silicon, 5 to 8 parts of magnesium, 0.5 to 2 parts of rare earths, 0.8 to 2 parts of calcium, 0.3 to 1 part of aluminum, and <40 ppm parts of boron.

6. The method for preparing a low-boron spheroidizing agent according to claim 5, characterized in that the number of parts of each raw material contained in the spheroidizing agent is 40 parts of silicon, 5 parts of magnesium, 0.5 parts of rare earths, 0.8 parts of calcium, 0.3 parts of aluminum, and <40 ppm parts of boron.

7. The method for preparing a low-boron spheroidizing agent according to claim 5, characterized in that the number of parts of each raw material contained in the spheroidizing agent is 50 parts of silicon, 8 parts of magnesium, 2 parts of rare earth elements, 2 parts of calcium, 1 part of aluminum, and <40 ppm parts of boron.

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