Method for controlling quantity of smelted metal in smelting of vacuum consumable electrode arc skull furnace

Abstract

The invention relates to a method for controlling the amount of smelted metal in smelting of a vacuum consumable electrode arc skull furnace, belongs to the field of titanium alloy smelting, and solves the problem of inaccurate control of the amount of smelted metal in an existing method. Comprising the steps that the inner diameter size of a skull, the height size of a crucible, the radius size of an electrode, the radius size of the crucible and the amount of metal needed for smelting are obtained, and the amount of metal capable of being contained in the crucible is determined according to the inner diameter size and the height size of the skull; the amount of metal capable of being contained in the crucible is compared with the amount of metal needed by smelting, and the electrode stroke when the needed amount of metal is smelted is determined according to the comparison result; taking the determined electrode stroke when the required metal amount is smelted as a target electrode stroke; and the real-time electrode stroke in the smelting process is collected, the target electrode stroke is compared with the real-time electrode stroke in the smelting process, and smelting is stopped when the real-time electrode stroke reaches the target electrode stroke. According to the method, the metal smelting amount can be controlled more accurately.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy smelting, in particular to a method for controlling the amount of smelted metal in vacuum consumable electrode arc skull furnace smelting. Background Art

[0002] Titanium and its alloys have the characteristics of high specific strength, high temperature resistance, corrosion resistance, stable performance, etc. It is a lightweight high-temperature structural material and has been widely used in aerospace, shipbuilding, energy, chemical industry and other fields. At present, in industrial production, most titanium alloy castings are smelted and cast in vacuum consumable electrode arc furnace.

[0003] During the smelting and pouring process of the crust furnace, the method of marking on the electrode is currently widely used in China to control the amount of smelting metal. Before the electrode is clamped, the length of the consumable electrode is calculated according to the required weight of the smelting metal and the diameter of the consumable electrode. At the corresponding length position, it is marked by spot welding wire, sponge titanium block, etc. During the smelting and pouring process, the operator observes the electrode through the observation window above the crust furnace. When the smelting reaches the marked position, the smelting is ended. However, this method has certain disadvantages. On the one hand, due to the structural problems of the equipment, the angle between the observation window and the electrode is greater than 60°, making observation extremely difficult; on the other hand, during the smelting process, there is splashing of the molten metal in the dry crucible. When the molten metal splashes onto the observation window, it will also have an adverse effect on the observation. Once the observation is wrong, a series of adverse effects will be produced on the melting and pouring. The amount of molten metal is directly related to whether the mold can be filled; when the amount of metal is too little, the mold is not full, and the casting may have under-casting defects at best, or even cause the casting to be scrapped at worst; when the amount of molten metal is too much, on the one hand, the molten metal is wasted and the production cost is increased, and on the other hand, the molten metal overflows the mold, which will cause great difficulties in the subsequent cleaning process of the mold and delay the production rhythm. Therefore, melting the right amount of metal is of great significance to the casting production of titanium alloy castings. Therefore, optimizing the method of controlling the amount of molten metal in the solidification furnace has a very positive significance for the production process using the solidification furnace. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a method for controlling the amount of molten metal in a vacuum consumable electrode arc shell furnace smelting, so as to solve the problem that the existing method for controlling the amount of molten metal in the process of smelting in a vacuum consumable electrode arc shell furnace for titanium alloys is inaccurate in controlling the amount of molten metal and cannot ensure that good ingots can be obtained in each smelting, which has a great impact on production efficiency and product quality.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions:

[0006] The present invention provides a method for controlling the amount of smelted metal in a vacuum consumable electrode arc skull furnace, comprising the following steps:

[0007] S1: Obtain the inner diameter of the solidified shell, the height of the crucible, the radius of the electrode, the radius of the crucible and the amount of metal required for smelting, and determine the amount of metal c that can be contained in the crucible according to the inner diameter and height of the solidified shell;

[0008] S2: Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting, and determine the electrode stroke d when the required amount of metal is smelted according to the comparison result;

[0009] S3: The electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke;

[0010] S4: Collect the real-time electrode stroke during the smelting process, compare the target electrode stroke with the real-time electrode stroke during the smelting process, and stop smelting when the real-time electrode stroke reaches the target electrode stroke.

[0011] Furthermore, in step S1, the amount of metal c that can be contained in the crucible satisfies:

[0012] c=ρbπa 2 ;

[0013] Where c is the mass of metal that can be contained in the crucible, kg;

[0014] a is the inner diameter of the condensate shell, mm;

[0015] b is the height of the solidified crust, mm.

[0016] Furthermore, in step S2, the metal mass c that can be contained in the crucible is compared with the metal mass M required for smelting. When the comparison result is c≥M, the electrode stroke d satisfies:

[0017] d=M(a 2 -r 2 ) / (ρπr 2 a 2 );

[0018] Where c is the mass of metal that can be contained in the crucible, kg;

[0019] d is the electrode stroke, mm;

[0020] M is the amount of metal required for smelting, kg;

[0021] a is the inner diameter of the condensate shell, mm;

[0022] r is the electrode radius, mm.

[0023] Furthermore, in step S2, the metal mass c that can be contained in the crucible is compared with the metal mass M required for smelting. When the comparison result is c<M, the electrode stroke d satisfies:

[0024] d = d1 + d2;

[0025] Where c is the mass of metal that can be contained in the crucible, kg;

[0026] M is the amount of metal required for smelting, kg;

[0027] d is the total electrode stroke, mm;

[0028] d1 is the electrode travel required for the amount of metal contained in the crucible, mm;

[0029] d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm.

[0030] Furthermore, the electrode travel d1 required by the amount of metal contained in the crucible satisfies:

[0031] d1=c(a 2 -r 2 ) / (ρπr 2 a 2 );

[0032] Where d1 is the electrode travel required for the amount of metal contained in the crucible, mm;

[0033] c is the mass of metal that can be contained in the crucible, kg;

[0034] a is the inner diameter of the condensate shell, mm;

[0035] r is the electrode radius, mm.

[0036] Furthermore, the electrode travel d2 required for the amount of metal exceeding the solidified shell portion satisfies:

[0037] d2=(Mc)(R 2 -r 2 ) / (ρπr 2 R 2 );

[0038] Where d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm;

[0039] c is the mass of metal that can be contained in the crucible, kg;

[0040] M is the amount of metal required for smelting, kg;

[0041] R is the crucible radius, mm;

[0042] r is the electrode radius, mm.

[0043] Furthermore, in S4, the real-time electrode position during the smelting process is collected by a sensor to determine the real-time electrode stroke.

[0044] Furthermore, in S4, the collected real-time electrode travel is displayed visually to facilitate the acquisition of the real-time electrode travel.

[0045] Furthermore, in S4, when the real-time electrode stroke reaches the target electrode stroke, smelting is stopped manually.

[0046] Furthermore, in S4, when the real-time electrode stroke reaches the target electrode stroke, smelting is stopped through the control system.

[0047] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0048] 1. The present invention can calculate the electrode stroke in the process of smelting metal in the vacuum consumable electrode arc skull furnace through the crucible radius, the electrode radius and the theoretical metal amount required for smelting. The stroke calculation is more convenient and quick. It is no longer necessary to calculate the required electrode length and perform spot welding, thus avoiding the risk of introducing excess materials during welding. In the actual smelting process, the amount of smelted metal can be more accurately controlled.

[0049] 2. The present invention can calculate the electrode stroke in the metal smelting process of the vacuum consumable electrode arc skull furnace through the crucible radius, the electrode radius and the theoretical metal amount required for smelting. Arc observers are no longer needed, thus avoiding the risk of metal liquid waste or product scrapping due to observation errors during the arc observation process. Through the method of the present invention, the electrode stroke is strictly calculated, thereby controlling the amount of smelting metal in the actual smelting process more accurately.

[0050] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0052] Figure 1 This is a schematic diagram of the electrode travel before and after smelting metal in the method of the present invention;

[0053] Figure 2 A schematic diagram of an observation window of a vacuum consumable electrode arc shell furnace used in a comparative example of the present invention;

[0054] Figure 3 This is a diagram of the smelting results of an embodiment of the present invention;

[0055] Figure 4 This is a diagram of the comparative smelting results of the present invention.

[0056] δ-the distance between the lower end surface of the electrode and the metal liquid surface; d-the electrode stroke; R-the radius of the crucible; r-the radius of the electrode; L-the length consumed by the electrode in the method of the present invention, l-the height to which the metal liquid surface in the crucible rises in the method of the present invention. DETAILED DESCRIPTION

[0057] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0058] The present invention provides a method for controlling the amount of smelting metal in a vacuum consumable electrode arc shell furnace smelting, comprising:

[0059] S1: Obtain the inner diameter of the solidified shell, the height of the crucible, the radius of the electrode, the radius of the crucible and the amount of metal required for smelting, and determine the amount of metal c that can be contained in the crucible according to the inner diameter and height of the solidified shell;

[0060] S2: Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting, and determine the electrode stroke d when the required amount of metal is smelted according to the comparison result;

[0061] S3: The electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke;

[0062] S4: Collect the real-time electrode stroke during the smelting process, compare the target electrode stroke with the real-time electrode stroke during the smelting process, and stop smelting when the real-time electrode stroke reaches the target electrode stroke.

[0063] Specifically, in step S1, the amount of metal c that can be contained in the cylindrical crucible is calculated according to the inner diameter a and the height b of the solidified shell, c = ρbπa 2 ;

[0064] It should be noted that in the vacuum consumable electrode arc shell furnace, the electrode stroke can be set in the smelting operation interface, such as Figure 1 As shown in the figure, the electrode stroke is d; during the metal smelting process, the distance δ between the lower end of the electrode and the metal liquid level remains basically constant. After the electrode metal melts, the electrode becomes shorter and the metal liquid level rises. Since the electrode radius r is smaller than the crucible radius R, to keep δ constant, the electrode needs to be lowered. The electrode lowering distance d is the electrode stroke. Therefore, the amount of smelting metal can be controlled by controlling the electrode stroke in the solidification furnace. Figure 1As shown in the figure, specifically, in step S2, the amount of metal c that can be contained in the crucible is compared with the amount of metal M required for smelting, and the electrode stroke d when the required amount of metal is smelted is determined according to the comparison result:

[0065] Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting. If c ≥ M, then the electrode travel d = M (a 2 -r 2 ) / (ρπr 2 a 2 )

[0066] Where, d is the electrode stroke, mm;

[0067] M is the amount of metal required for smelting, kg;

[0068] a is the inner radius of the condensate shell, mm;

[0069] r is the electrode radius, mm.

[0070] Compare the metal mass c that can be contained in the crucible with the metal mass M required for smelting. When the comparison result is c<M, the electrode stroke d satisfies:

[0071] d = d1 + d2;

[0072] Where c is the mass of metal that can be contained in the crucible, kg;

[0073] M is the amount of metal required for smelting, kg;

[0074] d is the total electrode stroke, mm;

[0075] d1 is the electrode travel required for the amount of metal contained in the crucible, mm;

[0076] d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm.

[0077] Among them, the electrode travel required for the amount of metal contained in the crucible is:

[0078] d1=c(a 2 -r 2 ) / (ρπr 2 a 2 );

[0079] Where d1 is the electrode travel required for the amount of metal contained in the crucible, mm;

[0080] c is the mass of metal that can be contained in the crucible, kg;

[0081] a is the inner diameter of the condensate shell, mm;

[0082] r is the electrode radius, mm.

[0083] Among them, the electrode travel required for the amount of metal exceeding the solidified shell is:

[0084] d2=(Mc)(R 2 -r 2 ) / (ρπr 2 R 2 );

[0085] Where d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm;

[0086] c is the mass of metal that can be contained in the crucible, kg;

[0087] M is the amount of metal required for smelting, kg;

[0088] R is the crucible radius, mm;

[0089] r is the electrode radius, mm.

[0090] Afterwards, the electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke, the real-time electrode position during the smelting process is collected by sensors, and the real-time electrode stroke is obtained and determined in time through visual display; when the real-time electrode stroke reaches the target electrode stroke, smelting is stopped manually or through the control system.

[0091] The present invention can calculate the electrode stroke in the process of smelting metal in a vacuum consumable electrode arc skull furnace by obtaining the inner diameter size of the shell, the height size of the crucible, the radius size of the electrode, the radius size of the crucible and the amount of metal required for smelting. The electrode stroke calculation is more convenient and quick, and there is no need to calculate the required electrode length and perform spot welding, thereby avoiding the risk of introducing excess materials during the welding process; there is no need for arc observers, thereby avoiding the risk of wasting molten metal or scrapping products due to observation errors during the arc observation process. Through the method of the present invention, the electrode stroke is strictly calculated, thereby controlling the amount of smelted metal more accurately.

[0092] Example 1

[0093] This embodiment provides a method for controlling the amount of smelted metal in a vacuum consumable electrode arc skull furnace smelting. This embodiment smelts titanium alloy, including:

[0094] S1: Obtain the inner diameter of the solidified shell, the height of the crucible, the radius of the electrode, the radius of the crucible and the amount of metal required for smelting, and determine the amount of metal c that can be contained in the crucible according to the inner diameter and height of the solidified shell:

[0095] The shell furnace used in this embodiment is a 500kg shell furnace, with a shell inner radius a=265mm, a height b=45m, a crucible radius R=225mm, and an electrode radius r=200mm; the titanium alloy density is 0.0000045kg / mm 3 ;

[0096] Calculate the amount of metal that can be contained in the crucible c = ρbπa 2 =44.7kg;

[0097] S2: Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting. According to the comparison result, determine the electrode stroke d when the required amount of metal is smelted:

[0098] The theoretical amount of metal required for this smelting is M = 457 kg. Since c < M, first calculate the electrode travel required for the amount of metal c contained in the crucible. At this time, the amount of metal M in the casting is c, and the radius of the crucible R is the inner diameter of the solidified shell a. Substitute d1 = c (a 2 -r 2 ) / (ρπr 2 a 2 ), it can be calculated that the electrode travel of this part is d1 = c(a 2 -r 2 ) / (ρπr 2 a 2 )=44.7*(265 2 -200 2 ) / (0.0000045*3.14*265 2 *200 2 )=34mm;

[0099] Calculate the electrode travel required for the amount of metal e that exceeds the solidified shell, e = Mc = 412.3 kg. At this time, the amount of smelting metal is e, the crucible diameter is R, and d2 = e (R 2 -r 2 ) / (ρπr 2 R 2 )=412.3*(225 2 -200 2 ) / (0.0000045*3.14*225 2 *200 2 )=153mm;

[0100] Then the electrode travel d = d1 + d2 = 187 mm when melting the required amount of metal M;

[0101] S3: The electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke;

[0102] S4: Collect the real-time electrode stroke during the smelting process, compare the target electrode stroke with the real-time electrode stroke during the smelting process, and when the real-time electrode stroke reaches the target electrode stroke of 187 mm, stop the smelting manually.

[0103] Example 2

[0104] This embodiment provides a method for controlling the amount of smelted metal in a vacuum consumable electrode arc skull furnace smelting. This embodiment smelts titanium alloy, including:

[0105] S1: Obtain the inner diameter of the solidified shell, the height of the crucible, the radius of the electrode, the radius of the crucible and the amount of metal required for smelting, and determine the amount of metal c that can be contained in the crucible according to the inner diameter and height of the solidified shell:

[0106] The shell furnace used in this embodiment is a 500kg shell furnace, with a shell inner radius a=265mm, a height b=45m, a crucible radius R=225mm, and an electrode radius r=200mm; the titanium alloy density is 0.0000045kg / mm 3 ;

[0107] Calculate the amount of metal that can be contained in the crucible c = ρbπa 2 =44.7kg;

[0108] S2: Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting. According to the comparison result, determine the electrode stroke d when the required amount of metal is smelted:

[0109] The theoretical amount of metal required for this smelting is M = 43kg. Since c ≥ M, the electrode travel is:

[0110] d=M(a 2 -r 2 ) / (ρπr 2 a 2 )=43*(265 2 -200 2 ) / (0.0000045*3.14*265 2 *200 2 )

[0111] =32.74mm;

[0112] S3: The electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke;

[0113] S4: Collect the real-time electrode stroke during the smelting process, compare the target electrode stroke with the real-time electrode stroke during the smelting process, and when the real-time electrode stroke reaches the target electrode stroke of 32.74 mm, stop the smelting manually.

[0114] Comparative Example

[0115] This comparative example uses the same vacuum consumable electrode arc skull furnace as in Example 1, and smelts titanium alloy according to the existing observation + marking method, including the following steps:

[0116] S1: According to the theoretical amount of metal required for smelting, M is 457 kg, the electrode radius r is 200 mm, and according to M = ρhπr 2 , it can be calculated that the electrode consumption length h is 808.2mm, and the titanium sponge block is spot welded at 808.2mm from the bottom of the electrode for marking;

[0117] S2: Observe through the equipment observation window during the smelting and pouring process. When the smelting reaches the marked position, the smelting is ended. The observation window is as follows: Figure 2 As shown in the figure, due to the limited viewing angle, lack of light source in the furnace, and the splashing of molten metal during the smelting process on the electrode surface to produce metal slag, which was confused with the sponge titanium block, resulting in wrong judgment. After the wrong judgment, the casting failed. The casting result is as follows Figure 3 shown.

[0118] This comparative example failed to accurately control the amount of smelting metal in the actual smelting process.

[0119] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for controlling the amount of smelting metal in a vacuum consumable electrode arc skull furnace, characterized in that: The following steps are involved: S1: Obtain the inner diameter of the solidified shell, the height of the crucible, the radius of the electrode, the radius of the crucible and the amount of metal required for smelting, and determine the amount of metal c that can be contained in the crucible according to the inner diameter and height of the solidified shell; S2: Compare the amount of metal c that can be contained in the crucible with the amount of metal M required for smelting, and determine the electrode stroke d when the required amount of metal is smelted according to the comparison result; S3: The electrode stroke for smelting the required amount of metal determined in step S2 is used as the target electrode stroke; S4: Collect the real-time electrode stroke during the smelting process, compare the target electrode stroke with the real-time electrode stroke during the smelting process, and stop smelting when the real-time electrode stroke reaches the target electrode stroke.

2. The method according to claim 1, characterized in that In step S1, the amount of metal c that can be contained in the crucible satisfies: c=ρbπa 2 ; Where c is the mass of metal that can be contained in the crucible, kg; a is the inner diameter of the condensate shell, mm; b is the height of the solidified crust, mm.

3. The method according to claim 1, characterized in that: In step S2, the metal mass c that can be contained in the crucible is compared with the metal mass M required for smelting. When the comparison result is c≥M, the electrode stroke d satisfies: d=M(a 2 -r 2 ) / (ρπr 2 a 2 ); Where c is the mass of metal that can be contained in the crucible, kg; d is the electrode stroke, mm; M is the amount of metal required for smelting, kg; a is the inner diameter of the condensate shell, mm; r is the electrode radius, mm.

4. The method according to claim 1, characterized in that In step S2, the metal mass c that can be contained in the crucible is compared with the metal mass M required for smelting. When the comparison result is c<M, the electrode stroke d satisfies: d = d1 + d2; Where c is the mass of metal that can be contained in the crucible, kg; M is the amount of metal required for smelting, kg; d is the total electrode stroke, mm; d1 is the electrode travel required for the amount of metal contained in the crucible, mm; d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm.

5. The method according to claim 4, characterized in that The amount of metal contained in the crucible requires the electrode travel d1 to satisfy: d1=c(a 2 -r 2 ) / (ρπr 2 a 2 ); Where d1 is the electrode travel required for the amount of metal contained in the crucible, mm; c is the mass of metal that can be contained in the crucible, kg; a is the inner diameter of the condensate shell, mm; r is the electrode radius, mm.

6. The method according to claim 4, characterized in that The electrode travel d2 required for the amount of metal exceeding the solidified shell part satisfies: d2=(M-c)(R 2 -r 2 ) / (ρπr 2 R 2 ); Where d2 is the electrode travel required for the amount of metal exceeding the solidified shell, mm; c is the mass of metal that can be contained in the crucible, kg; M is the amount of metal required for smelting, kg; R is the crucible radius, mm; r is the electrode radius, mm.

7. The method according to claim 1, characterized in that In S4, the real-time electrode position during the smelting process is collected by sensors to determine the real-time electrode stroke.

8. The method according to claim 7, characterized in that In the above S4, the collected real-time electrode travel is displayed visually to facilitate the acquisition of the real-time electrode travel.

9. The method according to claim 1, characterized in that: In S4, when the real-time electrode stroke reaches the target electrode stroke, smelting is stopped manually.

10. The method according to claim 1, characterized in that In S4, when the real-time electrode stroke reaches the target electrode stroke, smelting is stopped through the control system.

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