Smelting and casting method for engine oil nozzle

Abstract

According to the smelting and casting method of the engine oil nozzle, the raw material steel is smelted to be in the molten state, then the chemical components of the raw material steel are sampled, analyzed and adjusted, and the raw material steel is subjected to coarse deoxidation and fine deoxidation through four deoxidizing agents; and inert gas is introduced into the deoxidized raw material steel, metal titanium is supplemented into the deoxidized raw material steel, the raw material steel is discharged out of the furnace for casting after being subjected to slag removal, and a deoxidizing agent is added in the casting process for deoxidation. By means of a series of reactions, the technical key points of the chemical element adding amount, the chemical element adding time, the Ti element adding time, the deoxidation method and the like are utilized, it can be guaranteed that in the smelting process of the material, generation of oxides can be reduced, and then the defects of surface air holes, slag inclusion, cracks and the like of a cast product are reduced, so that the product quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of aviation engines, and in particular to a melting and casting method for an engine fuel injection nozzle. Background Art

[0002] Aircraft engine fuel injectors are used in the field of aircraft engines. The function of aircraft engine fuel injectors is to atomize (or vaporize) the fuel, which can accelerate the formation of the mixture, ensure the stable combustion of the fuel and improve the combustion efficiency. During use, the quality (external and internal) of aircraft engine fuel injectors is highly required and no defects are allowed.

[0003] In the prior art, aircraft engine fuel injectors often use stainless steel 1Cr18Ni9Ti, but the Ti element is relatively active and easily reacts with oxygen to produce oxides, causing defects such as pores, slag inclusions, and cracks on the surface of the product after casting, thereby affecting product quality. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a smelting and casting method for an engine fuel injector, which solves the problem of excessive oxides in the smelting and casting process of the engine fuel injector in the prior art.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] An embodiment of the present invention provides a method for melting and casting an engine fuel injector, comprising:

[0009] The raw steel is placed in a melting furnace to be melted to a molten state, and the raw steel contains titanium;

[0010] Sampling and analyzing the raw steel in the molten state, and adjusting the chemical composition of the raw steel to be within a preset range;

[0011] A first deoxidizer, a second deoxidizer, and a slag-forming agent are sequentially added into the smelting furnace to perform a first deslagging on the raw material steel in a molten state. Next, a third deoxidizer and a slag-forming agent are sequentially added into the smelting furnace to perform a second deslagging on the raw material steel in a molten state. Finally, a fourth deoxidizer is added into the smelting furnace.

[0012] Inert gas is introduced into the smelting furnace to stir the raw steel in a molten state;

[0013] Adding metallic titanium into the smelting furnace so that the titanium content in the smelting furnace reaches a preset qualified value;

[0014] Add slag-forming agent into the smelting furnace to perform the third deslagging of the molten raw steel, and control the time to be less than or equal to 2 minutes;

[0015] The raw steel after slag removal is taken out of the furnace for casting. During the casting process, the fourth deoxidizer is added and the casting time is controlled to be 3 minutes to 4 minutes.

[0016] Preferably, the preset range of the chemical composition of the raw steel is: in terms of mass percentage, C: ≤0.12%, Si: ≤1.0%, Mn: ≤2.0%, P: ≤0.035%, S: ≤0.03%, Cr: 17.0%~19.0%, Ni: 8.0%~11.0%, and the remainder is Fe and non-negligible impurities.

[0017] Preferably, the preset qualified value of the titanium content is related to the preset range of the carbon content, and the relationship between the two is:

[0018] M Ti =5*(M C -0.02)-0.8;

[0019] Among them, M Ti Expressed as the preset qualified value of titanium content, M C A chemical composition value expressed as carbon content.

[0020] Preferably, the method comprises:

[0021] The temperature in the smelting furnace is controlled at 1510°C-1550°C, the molten raw steel is sampled and analyzed, the temperature in the smelting furnace is controlled at 1560°C-1580°C, a first deoxidizer, a second deoxidizer and a slag-forming agent are sequentially added into the smelting furnace, the molten raw steel is deslaged for the first time, a third deoxidizer and a slag-forming agent are sequentially added into the smelting furnace, the molten raw steel is deslaged for the second time, the temperature in the smelting furnace is controlled at 1620°C-1640°C, a fourth deoxidizer is added into the smelting furnace, the temperature in the smelting furnace is controlled at 1640°C-1680°C, and the molten raw steel is deslaged for the third time.

[0022] Preferably, the method comprises:

[0023] After adding the third deoxidizer, the slag-forming agent is covered on the surface of the raw steel so that there is no exposed part on the surface of the raw steel.

[0024] Preferably, the method comprises:

[0025] During the casting process, inert gas is introduced into the upper end of the smelting furnace.

[0026] Preferably, the first deoxidizer is a manganese-iron alloy;

[0027] The second deoxidizer is ferrosilicon alloy;

[0028] The third deoxidizer is calcium silicon manganese;

[0029] The fourth deoxidizer is aluminum wire.

[0030] Preferably, the amount of ferromanganese alloy added is 0.2% to 0.3% of the mass of the raw steel;

[0031] The addition amount of ferrosilicon alloy is 0.2% to 0.3% of the raw steel mass;

[0032] The addition amount of calcium silicon manganese is 0.2% to 0.4% of the raw steel mass;

[0033] The amount of aluminum wire added is 0.1% to 0.2% of the mass of the raw steel.

[0034] Preferably, the smelting furnace comprises:

[0035] A furnace body, wherein the furnace body is formed with a first accommodating cavity, and the first accommodating cavity is used for melting raw steel;

[0036] A cover body, the cover body is arranged to cover the first accommodating cavity of the furnace body, the cover body forms a second accommodating cavity, and the second accommodating cavity is filled with an inert gas;

[0037] The gas blowing valve is used to connect to the inert gas and control the inert gas to enter the smelting furnace.

[0038] Preferably, the smelting furnace further comprises: a feeding assembly, the feeding assembly comprising:

[0039] A carrying box, wherein the carrying box is formed with a feeding hole;

[0040] A feeding rod is connected to the carrying box.

[0041] (III) Beneficial effects

[0042] The beneficial effects of the present invention are as follows: the smelting and casting method of the engine fuel injector mentioned in the present application is to melt the raw steel to a molten state, and then sample and analyze and adjust its chemical composition, and use four deoxidizers to perform rough deoxidation and fine deoxidation, and add metal titanium to the raw steel after deoxidation by passing inert gas into the raw steel after deoxidation, and remove the slag from the raw steel before casting, and add deoxidizers during the casting process for deoxidation. Among them, a series of reactions are used to ensure that the material can reduce the generation of oxides during the smelting process, thereby reducing the defects such as pores on the surface of the product after casting, slag inclusions in the product, and cracks, so as to ensure the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1It is an operation flow chart of a melting and casting method of an engine fuel injection nozzle of the present invention;

[0044] Figure 2 It is a structural schematic diagram of a smelting furnace of the present invention;

[0045] Figure 3 It is a schematic structural diagram of a feeding assembly of a smelting furnace of the present invention.

[0046] Reference Numbers

[0047] The furnace body 110 , the first accommodating chamber 111 , the gas blowing valve 120 , the feeding assembly 130 , the carrying box 131 , and the feeding rod 132 . DETAILED DESCRIPTION

[0048] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0049] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0050] In these embodiments, unless otherwise specified, the parts and percentages are all measured by mass. "Parts by mass" refers to the basic unit of measurement representing the mass ratio relationship of multiple components. 1 part can represent any unit mass, such as 1g, 3.527g, etc. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts. "And / or" is used to indicate that one or both of the situations described may occur, for example, A and / or B include (A and B) and (A or B).

[0051] In the prior art, aircraft engine fuel injectors often use stainless steel 1Cr18Ni9Ti as raw material, but the Ti element therein is very easy to react with oxygen to produce oxides, resulting in defects such as pores, slag inclusions, and cracks on the surface of the product after casting. The present application provides a smelting and casting process method for aircraft engine fuel injectors. By controlling the reaction conditions, from the technical points such as the time of adding chemical elements, the time of adding Ti elements, and the deoxidation method, the generation of oxides of this material during the smelting process can be reduced, thereby avoiding the occurrence of defects such as pores, slag inclusions, and cracks in aircraft engine fuel injectors, thereby ensuring the quality of the product.

[0052] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0053] The present invention provides a method for melting and casting an engine fuel injection nozzle, referring to Figure 1 , the above method comprises:

[0054] Step S1: placing the raw steel in a smelting furnace to smelt it into a molten state;

[0055] Exemplarily, recycled materials can be put into the smelting furnace, and the smelting furnace is powered on for smelting. When the smelting furnace is powered on, the temperature rises, and the high temperature liquefies the raw steel in the smelting furnace to melt all the raw steel in the smelting furnace.

[0056] It should be noted that the above-mentioned raw steel can be stainless steel 1Cr18Ni9Ti, or any steel suitable for use in the present technical solution, and the present application does not make any limitation thereto. The above-mentioned raw steel contains titanium, and the titanium in the above-mentioned raw steel can exist in the form of carbide, or in the form of oxide, or in other possible forms of titanium, and the present application does not make any requirements thereon.

[0057] Step S2: sampling and analyzing the raw material steel in a molten state, and adjusting the chemical composition of the raw material steel to be within a preset range;

[0058] Exemplarily, the raw steel in the molten state is sampled and analyzed, and its chemical composition is adjusted. A preset range is set for the chemical elements in the raw steel, and components such as chromium, nickel, silicon, and manganese are added compared with the preset range. For chemical components that do not meet the preset range, they are adjusted to meet the requirements.

[0059] It should be noted that in this step, the raw steel may contain titanium, and the titanium content in the raw steel is recorded but not adjusted.

[0060] Step S3: sequentially adding a first deoxidizer, a second deoxidizer, and a slag-forming agent into the smelting furnace to perform a first deslagging on the raw material steel in a molten state, then sequentially adding a third deoxidizer and a slag-forming agent into the smelting furnace to perform a second deslagging on the raw material steel in a molten state, and then adding a fourth deoxidizer into the smelting furnace;

[0061] It should be noted that deoxidation of the raw steel after the chemical composition is adjusted can effectively remove the oxides therein. Exemplarily, in the early stage of smelting, a first deoxidizer is added to the smelting furnace, and in the middle stage of smelting, a second deoxidizer is added to the smelting furnace to roughly deoxidize the raw steel in the smelting furnace. Exemplarily, a third deoxidizer is added to the smelting furnace to finely deoxidize the raw steel, and a fourth deoxidizer is added to the smelting furnace to finally deoxidize the raw steel. After four steps of deoxidation, the oxide content in the raw steel can be effectively reduced.

[0062] It should be noted that adding a slag-forming agent to the raw steel can be used to separate the molten metal from the oxide, change the surface and interfacial tension between the molten raw steel and the slag, reduce the bonding force between the molten raw steel and the slag, effectively separate the raw steel from the slag, and improve the utilization rate of the raw steel.

[0063] Exemplarily, the slag-forming agent may be lead slag-forming agent. After adding it into the metal melt, a large number of bubbles can be released to stir the raw steel to a certain extent, and the slag entrained and adsorbed in the raw steel can be fully turned over and pulled to the surface of the raw steel liquid, which is conducive to the complete slag removal.

[0064] Step S4: introducing an inert gas into the smelting furnace, the inert gas is used to stir the raw steel in a molten state;

[0065] It should be noted that an inert gas is introduced into the smelting furnace, and the molten raw steel can be stirred by the inert gas, so that the temperature of the raw steel in various places in the smelting furnace is uniform.

[0066] Exemplarily, the inert gas may include argon, helium, etc., including but not limited to any inert gas that does not react with the substances in the smelting furnace, and the present application does not limit this.

[0067] In a feasible embodiment, the inert gas is argon, which is used to stir the raw steel in a molten state. The advantage of selecting argon is that it has low cost and high economic benefits.

[0068] Step S5: adding metallic titanium into the smelting furnace so that the titanium content in the smelting furnace reaches a preset qualified value;

[0069] It should be noted that, since titanium has a relatively active chemical property, adding metallic titanium after four deoxidations can reduce the loss of titanium and the production of oxides.

[0070] It should be noted that after the raw steel in the smelting furnace is stirred by the above-mentioned inert gas, metallic titanium is added to the smelting furnace. In the process of adding metallic titanium, the burning loss of metallic titanium during the smelting process needs to be considered.

[0071] Step S6: adding a slag-forming agent into the smelting furnace to perform a third deslagging on the molten raw steel, and controlling the time to be less than or equal to 2 minutes;

[0072] It should be noted that a slag-forming agent is added to the smelting furnace to thoroughly deslag the raw steel. In this case, the raw slag needs to be quickly deslaged 2 to 3 times, and the deslag time is controlled within 2 minutes.

[0073] Step S7: The raw steel after slag removal is taken out of the furnace for casting. During the casting process, a fourth deoxidizer is added and the casting time is controlled to be 3 minutes to 4 minutes.

[0074] For example, when the raw steel is taken out of the furnace for casting, when half of the raw steel is cast, the fourth deoxidizer can be added for supplementary deoxidation, and then the product is continuously cast, and the entire casting time is controlled to be completed within 3 minutes to 4 minutes.

[0075] The smelting and casting method of the engine fuel injector mentioned in this application is to melt the raw steel to a molten state, and then sample and analyze and adjust its chemical composition, and use four deoxidizers to perform rough deoxidation and fine deoxidation, and add metal titanium to the raw steel after deoxidation by passing inert gas into the raw steel after deoxidation, and remove the slag from the raw steel before casting, and add deoxidizers during the casting process for deoxidation. Among them, a series of reactions are used, from the technical points of the amount of chemical elements added, the time of adding chemical elements, the time of adding Ti elements, the deoxidation method, etc., to ensure that the material can reduce the generation of oxides during the smelting process, and then reduce the defects of pores, slag inclusions, cracks, etc. in the cast products, so as to ensure the quality of the products.

[0076] In this technical solution, the preset range is shown in the table:

[0077]

[0078] It should be noted that other possible chemical components may appear in the raw steel during the smelting process. The preset range of the above chemical components is shown in the above table.

[0079] Exemplarily, the raw steel in a molten state is sampled and analyzed, and compared with the above table, the content of each chemical component is adjusted to be within the above range.

[0080] In this technical solution, the preset qualified value of titanium content is related to the preset range of carbon content.

[0081] M Ti =5*(M C -0.02)-0.8;

[0082] Among them, M Ti Expressed as the preset qualified value of titanium content, M C The chemical composition value expressed as the carbon content.

[0083] It should be noted that the preset qualified value of the titanium content is related to the chemical composition value of the carbon content. Referring to the above table, the chemical composition value of the carbon content is within the preset range of carbon.

[0084] In this technical solution, the method includes:

[0085] The temperature in the smelting furnace is controlled at 1510°C-1550°C, the molten raw steel is sampled and analyzed, the temperature in the smelting furnace is controlled at 1560°C-1580°C, a first deoxidizer, a second deoxidizer and a slag-forming agent are sequentially added into the smelting furnace, the molten raw steel is deslaged for the first time, a third deoxidizer and a slag-forming agent are sequentially added into the smelting furnace, the molten raw steel is deslaged for the second time, the temperature in the smelting furnace is controlled at 1620°C-1640°C, a fourth deoxidizer is added into the smelting furnace, the temperature in the smelting furnace is controlled at 1640°C-1680°C, and the molten raw steel is deslaged for the third time.

[0086] Different steps are performed, and different temperature ranges need to be set. Controlling the temperature range of the reaction can reduce the generation of oxides.

[0087] In this technical solution, the method includes:

[0088] After the third deoxidizer is added, the slag-forming agent is covered on the surface of the raw steel so that there is no exposed part on the surface of the raw steel.

[0089] Exemplarily, after adding the third deoxidizer, the slag-forming agent is shaken into the smelting furnace in small amounts and multiple times, and the control time is 1 min to 2.5 min.

[0090] As a preferred technical solution of the present invention, the above control time is 1min to 2.5min, for example, 1min, 1.5min, 2min or 2.5min, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0091] For example, the liquid surface can be divided into several areas according to the liquid surface area of ​​the raw steel in a molten state, and the slag-forming agent is covered in each area. The slag-forming agent is jogged into the smelting furnace to make it evenly covered, and the third deoxidizer can also be fully melted so that sufficient slag can be made.

[0092] For example, the liquid surface is divided into areas according to the size of the liquid surface and the operator's habits, and can usually be divided into 5-10 areas.

[0093] In this technical solution, the method includes:

[0094] During the casting process, an inert gas is introduced into the upper end of the smelting furnace to prevent the raw steel from reacting with oxygen, thereby reducing the production of oxides.

[0095] In this technical solution, the first deoxidizer is a manganese-iron alloy;

[0096] The second deoxidizer is ferrosilicon alloy;

[0097] The third deoxidizer is calcium silicon manganese;

[0098] The fourth deoxidizer is aluminum wire.

[0099] It should be noted that the first deoxidizer uses manganese-ferroalloy to roughly deoxidize the raw steel. Carbon manganese-ferroalloy is mainly an alloy composed of two elements, manganese and iron. In the early stage of smelting, in the presence of oxygen and water vapor, the iron powder is oxidized into ferric hydroxide. Under the action of water and oxygen, the iron powder will be oxidized to produce Fe3O4 and Fe2O3, and oxygen and water will be absorbed. Using manganese-ferroalloy as the first deoxidizer can improve the strength of steel.

[0100] It should be noted that the second deoxidizer uses ferrosilicon alloy to deoxidize the raw steel. In the middle stage of smelting, since a large amount of heat is released when SiO2 is generated, ferrosilicon alloy helps to increase the temperature of the raw steel while deoxidizing. For example, ferrosilicon can also be used as an alloying element additive.

[0101] It should be noted that the third deoxidizer uses calcium silicon manganese to deoxidize the raw steel. The advantage of calcium silicon manganese is that calcium has a strong deoxidation ability, but the calcium vapor pressure at steelmaking temperature is very high, and the solubility of calcium in the raw steel is relatively low. Calcium silicon manganese can partially overcome the shortcomings of slow deoxidation rate caused by calcium silicon alloy deoxidation, and the resulting inclusions are small spherical inclusions that are not easy to remove from the molten steel.

[0102] It should be noted that the fourth deoxidizer uses aluminum wire to deoxidize the raw steel. Aluminum is a strong deoxidizing element. Using aluminum wire as the final deoxidizer can not only reduce the generation of FeO, but also effectively inhibit the generation of steel slag (mainly FeO). Among them, aluminum can also combine with nitrogen to play a nitrogen fixing role, so it can also reduce the generation of pores.

[0103] In this technical solution, the amount of ferromanganese alloy added is 0.2% to 0.3% of the mass of the raw steel;

[0104] The addition amount of ferrosilicon alloy is 0.2% to 0.3% of the raw steel mass;

[0105] The addition amount of calcium silicon manganese is 0.2% to 0.4% of the raw steel mass;

[0106] The amount of aluminum wire added is 0.1% to 0.2% of the mass of the raw steel.

[0107] As a preferred technical solution of the present invention, the addition amount of the above-mentioned manganese iron alloy is 0.2% to 0.3% of the raw steel, such as 0.2%, 0.25%, 0.28% or 0.3%, etc., but is not limited to the listed values, and other unlisted values ​​within the above-mentioned numerical range are also applicable.

[0108] As a preferred technical solution of the present invention, the addition amount of the above-mentioned ferrosilicon alloy is 0.2% to 0.3% of the raw steel, for example, 0.2%, 0.25%, 0.28% or 0.3%, etc., but is not limited to the listed values, and other unlisted values ​​within the above-mentioned numerical range are also applicable.

[0109] As a preferred technical solution of the present invention, the addition amount of the above-mentioned calcium silicon manganese is 0.2% to 0.4% of the raw steel, for example 0.2%, 0.25%, 0.3% or 0.35%, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0110] refer to Figure 2 , the present application provides a smelting furnace, comprising:

[0111] A furnace body 110, wherein the furnace body 110 is formed with a first accommodating chamber 111, and the first accommodating chamber 111 is used for melting raw steel;

[0112] A cover body, wherein the cover body is filled with an inert gas;

[0113] The gas injection valve 120 is used to connect to the external inert gas and control the inert gas to be injected into the melting furnace.

[0114] It should be noted that the smelting furnace mentioned in the present application includes: a furnace body 110, the furnace body 110 is formed with a first accommodating chamber 111, the raw steel is melted at high temperature in the first accommodating chamber 111, and the above-mentioned heating method can be heating by power transmission, or other heating methods applicable to the present technical solution, which will not be described in detail here. Exemplarily, the inner wall of the furnace body 110 of the present application is made of refractory raw materials. During the smelting process, the use of refractory raw materials can improve the stability and safety of the smelting operation, and the smelting furnace mentioned in the present application has high production efficiency and low energy consumption.

[0115] In the present technical solution, the smelting furnace also includes a cover body, wherein the cover body can be filled with an inert gas, which can prevent the raw steel from undergoing an oxidation reaction with oxygen in the air during the casting process and can reduce the generation of oxides during the smelting and casting process.

[0116] For example, during the casting process, Ar gas is filled into the cover body to prevent the raw steel from having an oxidation reaction with oxygen in the air during the casting process.

[0117] The smelting furnace mentioned in the present application further includes: a gas injection valve 120. Exemplarily, the gas injection valve 120 is connected to the furnace body 110 through a pipeline and controls the entry of inert gas.

[0118] Illustratively, in a feasible implementation manner, the smelting furnace mentioned in the present application may further include: a driving device for introducing an inert gas into the above-mentioned smelting furnace.

[0119] In this technical solution, reference Figure 3 The smelting furnace includes: a feeding assembly 130, and the feeding assembly 130 includes:

[0120] A carrying box 131, wherein the carrying box 131 is formed with a feeding hole;

[0121] The feeding rod 132 is connected to the carrying box 131 .

[0122] It should be noted that the feeding assembly 130 includes a supporting box 131, which is used to hold the raw materials required in the smelting process. The supporting box 131 is formed with a feeding hole. During the feeding process, the supporting box 131 is placed in the molten material, and the required raw materials in the supporting box 131 are melted at high temperature and then integrated into the molten material through the feeding hole. Based on this arrangement, the loss of the fed material can be reduced.

[0123] It should be noted that the feeding assembly 130 also includes a feeding rod 132 . The feeding rod 132 is connected to the carrying box 131 . During the feeding process, the carrying box 131 is placed in the molten material, and the feeding rod 132 is used to hold the material.

[0124] For example, the titanium metal may be placed in the carrier box 131 , and then the carrier box 131 may be inserted into the raw steel in a molten state to melt the titanium metal. Based on this feeding method, the burning loss of titanium may be reduced.

[0125] Example 1

[0126] In a feasible implementation, raw steel may be placed in a smelting furnace, and power may be supplied to the smelting furnace to increase the temperature. After the raw steel in the smelting furnace is molten, the temperature thereof may be controlled at 1510°C to 1550°C.

[0127] Referring to the table below, the raw steel in the above smelting furnace is sampled and analyzed to obtain a row of values ​​for the furnace test, and its chemical composition is adjusted according to the preset range, and the elements such as chromium, nickel, silicon, and manganese are added to be within the preset range. The raw steel in the furnace is sampled and analyzed again to obtain a row of values ​​for the furnace test. The above values ​​are within the preset range.

[0128]

[0129] The smelting furnace is continuously powered on to increase the temperature. When the temperature reaches 1560-1580°C, the first deoxidizer: 0.2%-0.3% ferromanganese alloy and the second deoxidizer: 0.2%-0.3% ferrosilicon alloy are added as pre-deoxidation, and then slag removal is performed. After slag removal, 0.2%-0.4% fine granular calcium silicon manganese is added as the third deoxidizer. The time is controlled to be 1min-2.5min. The slag-making agent is jogged into the smelting furnace in small amounts and multiple times to ensure uniform coverage, so that the calcium silicon manganese is fully melted, and then the slag is fully removed.

[0130] When the temperature rises to 1620-1640°C, pure aluminum wire accounting for 0.1% of the raw steel mass is added as the fourth deoxidizer, and the aluminum wire is quickly inserted from the liquid surface of the raw steel into the interior of the raw steel to fully fuse and deoxidize the aluminum wire and the raw steel.

[0131] After the aluminum wire is added, the Ar gas valve at the bottom of the furnace is opened and the molten steel in the furnace is stirred with Ar gas. The molten steel is deoxidized and the temperature of the molten steel in the furnace is uniform. The control time is 1min to 2.5min.

[0132] After the Ar gas treatment is completed, metal titanium with a carbon content within a preset range is quickly added into the smelting furnace. In order to reduce the burning loss of titanium, the metal titanium is placed on the feeding assembly 130 and inserted into the molten raw steel for melting.

[0133] When the molten steel temperature reaches 1640-1680℃, stop supplying power to raise the temperature and quickly remove the slag 2-3 times within 2 minutes.

[0134] Adjust the temperature of the molten steel to the casting temperature, start casting from the furnace, and when half of the raw steel is cast, insert 0.1% aluminum wire again for supplementary deoxidation, and continue casting the product. The casting time is controlled at 3 to 4 minutes.

[0135] In the description of the present invention, each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0136] In the description of the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "comprising one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0137] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0138] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0139] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for melting and casting an engine fuel injector, characterized in that: The method comprises: The raw steel is placed in a melting furnace and melted to a molten state; Sampling and analyzing the raw material steel in a molten state, and adjusting the chemical composition of the raw material steel to be within a preset range; Adding a first deoxidizer, a second deoxidizer, and a slag-forming agent into the smelting furnace in sequence, and performing a first deslagging on the raw material steel in the molten state; then, adding a third deoxidizer and the slag-forming agent into the smelting furnace in sequence, and performing a second deslagging on the raw material steel in the molten state; and then adding a fourth deoxidizer into the smelting furnace; Introducing an inert gas into the smelting furnace, wherein the inert gas is used to stir the raw steel in a molten state; Adding metallic titanium into the smelting furnace so that the titanium content in the smelting furnace reaches a preset qualified value; Adding the slag-forming agent into the smelting furnace, performing a third deslagging on the raw steel in the molten state, and controlling the time to be less than or equal to 2 minutes; The raw steel after slag removal is taken out of the furnace for casting. During the casting process, the fourth deoxidizer is added and the casting time is controlled to be 3 minutes to 4 minutes.

2. The method for melting and casting an engine fuel injector according to claim 1, characterized in that: The preset range of the chemical composition of the raw steel is: in terms of mass percentage, C: ≤0.12%, Si: ≤1.0%, Mn: ≤2.0%, P: ≤0.035%, S: ≤0.03%, Cr: 17.0%~19.0%, Ni: 8.0%~11.0%, and the remainder is Fe and non-negligible impurities.

3. The method for melting and casting an engine fuel injection nozzle according to claim 2, characterized in that: The preset qualified value of titanium content is related to the chemical composition value of carbon content, and the relationship between the two is: M Ti =5*(M C -0.02)-0.8; Among them, M Ti The preset qualified value of the titanium content is expressed as C The chemical composition value expressed as the carbon content.

4. The method for melting and casting an engine fuel injector according to claim 1, characterized in that: include: The temperature in the smelting furnace is controlled to be 1510°C-1550°C, the raw steel in the molten state is sampled and analyzed, the temperature in the smelting furnace is controlled to be 1560°C-1580°C, a first deoxidizer, a second deoxidizer, and a slag-forming agent are sequentially added into the smelting furnace, the raw steel in the molten state is deslaged for the first time, a third deoxidizer and the slag-forming agent are sequentially added into the smelting furnace, the raw steel in the molten state is deslaged for the second time, the temperature in the smelting furnace is controlled to be 1620°C-1640°C, the fourth deoxidizer is added into the smelting furnace, the temperature in the smelting furnace is controlled to be 1640°C-1680°C, and the raw steel in the molten state is deslaged for the third time.

5. The method for melting and casting an engine fuel injection nozzle according to claim 1, characterized in that: Methods include: After the third deoxidizer is added, the slag-forming agent is covered on the surface of the raw steel so that there is no exposed part on the surface of the raw steel.

6. The method for melting and casting an engine fuel injection nozzle according to claim 1, characterized in that: Methods include: During the casting process, inert gas is introduced into the upper end of the smelting furnace.

7. The method for melting and casting an engine fuel injection nozzle according to claim 1, characterized in that: The first deoxidizer is ferromanganese alloy; The second deoxidizer is ferrosilicon alloy; The third deoxidizer is calcium silicon manganese; The fourth deoxidizer is aluminum wire.

8. The method for melting and casting an engine fuel injection nozzle according to claim 7, characterized in that: The addition amount of the ferromanganese alloy is 0.2% to 0.3% of the mass of the raw steel; The addition amount of the ferrosilicon alloy is 0.2% to 0.3% of the mass of the raw steel; The amount of calcium silicon manganese added is 0.2% to 0.4% of the mass of the raw steel; The added amount of the aluminum wire is 0.1% to 0.2% of the mass of the raw steel.

9. The method for melting and casting an engine fuel injection nozzle according to claim 1, characterized in that: The smelting furnace comprises: A furnace body, wherein the furnace body is formed with a first accommodating cavity, and the first accommodating cavity is used for melting the raw steel; A cover body, the cover body is arranged to cover the first accommodating cavity of the furnace body, the cover body forms a second accommodating cavity, and the second accommodating cavity is filled with an inert gas; A gas blowing valve is used to connect to the inert gas and control the inert gas to enter the smelting furnace.

10. The method for melting and casting an engine fuel injection nozzle according to claim 9, characterized in that: The smelting furnace also includes: A feeding assembly, the feeding assembly comprising: A carrying box, wherein the carrying box is formed with a feeding hole; A feeding rod is connected to the carrying box.

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