Metal material solidification structure regulation and control method based on furnace shell temperature online monitoring
阅读说明：本技术 基于炉壳温度在线监测的金属材料凝固组织调控方法 (Metal material solidification structure regulation and control method based on furnace shell temperature online monitoring ) 是由 刘全明 龙伟民 纠永涛 傅莉 钟素娟 马佳 于奇 于 2020-08-11 设计创作，主要内容包括：本申请涉及金属材料真空电弧熔炼技术领域,尤其是涉及一种基于炉壳温度在线监测的金属材料凝固组织调控方法,包括如下步骤：根据待熔炼合金样品的最低共析转变温度确定熔炼炉的炉膛的气氛极限温度,再计算得出炉壳的极限温度；熔炼炉的位于炉内坩埚的上端面及上端面以上空间所对应的外炉壳形成有至少两个测量位置,且在测量位置处对炉壳进行测温,且使得实测的炉壳温度始终小于或者等于炉壳的极限温度。可见,通过将炉膛的气氛温度与炉壳的温度关联起来,通过测量炉壳的温度,确保炉膛的温度不至于过高而产生铸锭组织偏析,即通过本基于炉壳温度在线监测的金属材料凝固组织调控方法能够有效避免组织偏析的产生,使得熔炼组织更加均匀。(The application relates to the technical field of metal material vacuum arc melting, in particular to a metal material solidification structure regulating and controlling method based on furnace shell temperature online monitoring, which comprises the following steps: determining the atmosphere limit temperature of a hearth of a smelting furnace according to the lowest eutectoid transition temperature of an alloy sample to be smelted, and then calculating to obtain the limit temperature of a furnace shell; the outer furnace shell of the smelting furnace corresponding to the upper end surface of the crucible in the furnace and the space above the upper end surface is provided with at least two measuring positions, the temperature of the furnace shell is measured at the measuring positions, and the actually measured temperature of the furnace shell is always smaller than or equal to the limit temperature of the furnace shell. Therefore, the atmosphere temperature of the hearth is associated with the temperature of the furnace shell, and the temperature of the furnace shell is measured, so that the temperature of the hearth is not too high to generate ingot casting structure segregation, namely, the generation of the structure segregation can be effectively avoided through the metal material solidification structure regulation and control method based on the furnace shell temperature online monitoring, and the smelting structure is more uniform.)
1. A method for regulating and controlling a solidification structure of a metal material based on furnace shell temperature online monitoring is characterized by comprising the following steps:
determining the atmosphere limit temperature of a hearth of the smelting furnace according to the lowest eutectoid transition temperature of an alloy sample to be smelted, and further calculating to obtain the limit temperature of a furnace shell;
the upper end face of a crucible in the smelting furnace and the outer furnace shell corresponding to the space above the upper end face are provided with at least two measuring positions, the temperature of the furnace shell is measured at the measuring positions, and the actually measured temperature of the furnace shell is always smaller than or equal to the limit temperature of the furnace shell.
2. The furnace shell temperature on-line monitoring-based metal material solidification structure regulating method as claimed in claim 1, wherein the number of the measuring positions is three, and the three measuring positions are respectively formed right in front of, right behind and right to one side of the outer furnace shell.
3. The furnace shell temperature on-line monitoring-based metallic material solidification structure regulation and control method as claimed in claim 1, characterized in that any two elements of the constituent elements of the alloy sample to be smelted are combined into an alloy system, and the alloy system with the corresponding binary phase diagram is screened out, and the eutectoid transformation temperature of the alloy system is obtained through the corresponding binary phase diagram;
and selecting the eutectoid transformation temperature with the minimum value as the atmosphere limit temperature of the hearth through comparison.
4. The method for regulating and controlling the solidification structure of the metal material based on the on-line monitoring of the furnace shell temperature as claimed in claim 3, wherein the derivation process of the limit temperature of the furnace shell is shown in the formula (1) to the formula (5):
in the formula, tn+1Ultimate temperature (. degree. C.) of the outer shell, q-Total Heat removal (W), an-total heat dissipation factor (W/m)2·K)，tα-ambient temperature (25 ℃);
an＝anR+anC(2)，
in the formula: a isnRRadiation heat dissipation coefficient (W/m)2·K)，anC-coefficient of convective heat dissipation (W/m)2·K)；
In the formula: -blackness factor of the slab radiative heat transfer;
in the formula: a-position coefficient, ξ -wind speed coefficient, u-wind speed (m/s);
λ＝b+(cE-5)*t1(6)，
in the formula: lambda-thermal conductivity (W/m.K), t1Temperature (. degree. C.) of the atmosphere in the furnace, bC-coefficient, obtaining the heat conductivity coefficient of the material at different temperatures according to the material of the furnace shell of the smelting furnace, and then performing linear fitting to obtain coefficients b and c;
in the formula: R-Total thermal resistance (K.m)2/W)；
The obtained atmosphere limit temperature of the hearth and the assumed limit temperature t of the furnace shelln+1And substituting the known data into the formulas (1) to (8), calculating the limit temperature of the furnace shell, comparing the calculated limit temperature of the furnace shell with the assumed limit temperature of the furnace shell, and when the error between the calculated limit temperature and the assumed limit temperature of the furnace shell is within a preset range, indicating that the calculated limit temperature of the furnace shell meets the requirement.
5. The furnace shell temperature on-line monitoring-based metal material solidification structure regulating method as claimed in any one of claims 1 to 4, wherein the manner of making the measured furnace shell temperature always less than or equal to the furnace shell limit temperature comprises: reducing the alloy charged in each crucible; and/or
The number of crucibles into which the alloy is put is reduced.
6. The furnace shell temperature on-line monitoring-based metal material solidification structure control method according to any one of claims 1 to 4, wherein the manner of always enabling the measured temperature of the furnace shell to be less than or equal to the limit temperature of the furnace shell further comprises: the melting time of the alloy in each crucible is shortened.
7. The furnace shell temperature on-line monitoring-based metal material solidification structure control method according to any one of claims 1 to 4, wherein the manner of always enabling the measured temperature of the furnace shell to be less than or equal to the limit temperature of the furnace shell further comprises: and after each time of smelting is finished, prolonging the time of next arc striking, and when the temperature of the atmosphere in the hearth is reduced to be less than or equal to the limit temperature of the furnace shell, starting the next arc striking smelting.
8. The furnace shell temperature on-line monitoring-based metal material solidification structure control method according to any one of claims 1 to 4, wherein the manner of always enabling the measured temperature of the furnace shell to be less than or equal to the limit temperature of the furnace shell further comprises: repeatedly smelting the alloy sample to be smelted for multiple times, and turning over the alloy to be smelted in the crucible between two adjacent smelting operations.
9. The furnace shell temperature on-line monitoring-based metal material solidification structure control method according to any one of claims 1 to 4, wherein the manner of always enabling the measured temperature of the furnace shell to be less than or equal to the limit temperature of the furnace shell further comprises: the smelting process comprises the operations of low-current positioning arcing, high-current alloy smelting and low-current crucible reversing.
10. A method for regulating and controlling a solidification structure of a metal material based on furnace shell temperature online monitoring is characterized by comprising the following steps:
taking the phase transition temperature of the pure metal sample to be smelted as the atmosphere limit temperature of the hearth of the smelting furnace, and then calculating to obtain the limit temperature of the furnace shell;
the upper end face of a crucible in the smelting furnace and the outer furnace shell corresponding to the space above the upper end face are provided with at least two measuring positions, the temperature of the furnace shell is measured at the measuring positions, and the actually measured temperature of the furnace shell is always smaller than or equal to the limit temperature of the furnace shell.
Technical Field
The application relates to the technical field of metal material vacuum arc melting, in particular to a metal material solidification structure regulating and controlling method based on furnace shell temperature online monitoring.
Background
At present, in order to ensure the component uniformity of the titanium alloy and other active metals for smelting ingot casting, a multiple smelting process is usually adopted in the vacuum arc smelting process, the repeated arc smelting heat release causes the temperature of vacuum or inert protective atmosphere to rise rapidly, so that the cooling rates of the upper end surface and the lower end surface of the ingot casting in the solidification process are greatly different (the upper end surface is mostly air cooling or furnace cooling, and the lower end surface is copper plate water cooling), the component segregation of the ingot casting seriously influences the quality of the ingot casting, and therefore, the reasonable control of the atmosphere temperature of a hearth has important significance.
Disclosure of Invention
The application aims to provide a method for regulating and controlling a solidification structure of a metal material based on-line monitoring of furnace shell temperature, and solves the technical problem that reasonable control of the atmosphere temperature of a hearth in the prior art is significant to a certain extent.
The application provides a method for regulating and controlling a solidification structure of a metal material based on furnace shell temperature online monitoring, which comprises the following steps:
determining the atmosphere limit temperature of a hearth of the smelting furnace according to the lowest eutectoid transition temperature of an alloy sample to be smelted, and further calculating to obtain the limit temperature of a furnace shell;
the upper end face of a crucible in the smelting furnace and the outer furnace shell corresponding to the space above the upper end face are provided with at least two measuring positions, the temperature of the furnace shell is measured at the measuring positions, and the actually measured temperature of the furnace shell is always smaller than or equal to the limit temperature of the furnace shell.
In the above technical solution, further, the number of the measurement positions is three, and the three measurement positions are respectively formed right in front of, right behind, and right on one side of the outer furnace shell.
In any one of the above technical solutions, further, any two elements of the constituent elements of the alloy sample to be smelted are combined into an alloy system, and the alloy system with the corresponding binary phase diagram is screened out, and the eutectoid transformation temperature of the alloy system is obtained through the corresponding binary phase diagram;
and selecting the eutectoid transformation temperature with the minimum value as the atmosphere limit temperature of the hearth through comparison.
In any of the above technical solutions, further, the derivation process of the limit temperature of the furnace shell is shown in formulas (1) to (5):
in the formula, tn+1Ultimate temperature (. degree. C.) of the outer shell, q-Total Heat removal (W), an-total heat dissipation factor (W/m)2·K)，tα-ambient temperature (25 ℃);
an＝anR+anC(2)，
in the formula: a isnRRadiation heat dissipation coefficient (W/m)2·K)，anC-coefficient of convective heat dissipation (W/m)2·K)；
In the formula: -blackness factor of the slab radiative heat transfer;
in the formula: a-position coefficient, ξ -wind speed coefficient, u-wind speed (m/s);
λ＝b+(cE-5)*t1(6)，
in the formula: lambda-thermal conductivity (W/m.K), t1-hearth (atmosphere) temperature (c), b, c-coefficients, obtaining thermal conductivity coefficients of the material at different temperatures according to the furnace shell material of the smelting furnace, and then performing linear fitting to obtain coefficients b and c;
in the formula: R-Total thermal resistance (K.m)2/W)；
The obtained atmosphere limit temperature of the hearth and the assumed limit temperature t of the furnace shelln+1And substituting the known data into the formulas (1) to (8), calculating the limit temperature of the furnace shell, comparing the calculated limit temperature of the furnace shell with the assumed limit temperature of the furnace shell, and when the error between the calculated limit temperature and the assumed limit temperature of the furnace shell is within a preset range, indicating that the calculated limit temperature of the furnace shell meets the requirement.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell includes: the alloy charged per crucible is reduced.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell further includes: the number of crucibles into which the alloy is put is reduced.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell further includes: the melting time of the alloy in each crucible is shortened.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell further includes: and after each time of smelting is finished, prolonging the time of next arc striking, and when the temperature of the atmosphere in the hearth is reduced to be less than or equal to the limit temperature of the furnace shell, starting the next arc striking smelting.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell further includes: repeatedly smelting the alloy sample to be smelted for multiple times, and turning over the alloy to be smelted in the crucible between two adjacent smelting operations.
In any of the above technical solutions, further, the manner of making the temperature of the furnace shell always less than or equal to the limit temperature of the furnace shell further includes: the smelting process comprises the operations of low-current positioning arcing, high-current alloy smelting and low-current crucible reversing.
The application provides a method for regulating and controlling a solidification structure of a metal material based on furnace shell temperature online monitoring, which comprises the following steps:
taking the phase transition temperature of the pure metal sample to be smelted as the atmosphere limit temperature of the hearth of the smelting furnace, and then calculating to obtain the limit temperature of the furnace shell;
the upper end face of a crucible in the smelting furnace and the outer furnace shell corresponding to the space above the upper end face are provided with at least two measuring positions, the temperature of the furnace shell is measured at the measuring positions, and the actually measured temperature of the furnace shell is always smaller than or equal to the limit temperature of the furnace shell.
Compared with the prior art, the beneficial effect of this application is:
in the metal material solidification structure regulation and control method based on furnace shell temperature on-line monitoring provided by the application, the atmosphere temperature of the hearth is associated with the temperature of the furnace shell, and ingot casting structure segregation is not generated due to overhigh temperature of the hearth through measuring the temperature of the furnace shell, namely, the generation of the structure segregation can be effectively avoided through the metal material solidification structure regulation and control method based on the furnace shell temperature on-line monitoring, so that the smelting structure is more uniform.
In addition, the measurement position is taken outside the furnace shell for measurement, compared with the mode that a thermocouple extends into the furnace for measurement in the prior art, the measurement method is more convenient and easy to implement, the service life of the measurement equipment is prolonged by the measurement mode, and the cost can be greatly reduced particularly in actual production.
Drawings
In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic flow chart of a method for regulating and controlling a solidification structure of a metal material based on-line monitoring of furnace shell temperature according to an embodiment of the present application;
FIG. 2 is a binary phase diagram of the Ni-Ti system provided in the examples of the present application;
FIG. 3 is a linear fitting graph of thermal conductivity coefficients of furnace shell materials of 1Cr18Ni9 at different temperatures according to an embodiment of the present application;
FIG. 4 is a macro topography of titanium-based solder ingot and ingot after 5 times of smelting provided by the embodiment of the application;
FIG. 5 is a microstructure diagram of a titanium-based brazing filler metal ingot and an ingot core provided in an embodiment of the present application;
fig. 6 is a schematic structural diagram of a smelting furnace provided in an embodiment of the present application;
fig. 7 is a schematic structural diagram of a smelting furnace according to an embodiment of the present application.
Reference numerals:
10-furnace cover, 20-furnace shell, 30-water-cooled copper plate, 40-crucible, 50-vacuum-pumping equipment and 60-electrode.
Detailed Description
The technical solutions of the present application will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present application.
The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application.
All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
The method for regulating the solidification structure of the metal material based on the online monitoring of the furnace shell temperature according to some embodiments of the present application is described below with reference to fig. 1 to 7.
Referring to fig. 1, an embodiment of the present application provides a method for regulating and controlling a solidification structure of a metal material based on furnace shell temperature online monitoring, which is suitable for both experiments and actual production, and the method includes the following steps:
Referring to fig. 6 and 7, the smelting furnace includes a
In addition, the measurement position is taken outside the furnace shell for measurement, compared with the mode that a thermocouple directly extends into the furnace for measurement in the prior art, the measurement method is more convenient and easy to implement, the service life of the measurement equipment is prolonged by the measurement mode, and the cost can be greatly reduced particularly in actual production.
Optionally, an infrared thermometer may be installed at the measurement position, and of course, the temperature measurement device is not limited thereto, and may also be selected according to actual needs.
The method is also suitable for pure metal, and the limit temperature of the furnace shell is calculated by taking the phase transition temperature of the pure metal sample to be smelted as the atmosphere limit temperature of the hearth of the smelting furnace at the moment, so that the pure metal sample to be smelted always keeps single phase composition in the smelting process, and other dispersed second phases are avoided.
Further, it is preferable that the number of the measurement positions is three, and the three measurement positions are formed right in front of, right behind, and one right side of the outer shell, respectively.
According to the above description, the three positions are uniformly distributed on the circumferential outer shell surface of the smelting furnace, and after the measurement and the average value are obtained, the measurement result is more accurate, and here, it is noted that, the measurement position is only arranged on one positive side, and the measurement position is not arranged on the other opposite positive side, mainly aiming at that one positive side of the existing smelting furnace on the market is mostly provided with a vacuum-pumping pipeline, so that the measurement position can be arranged only on one positive side.
And note that the three measuring positions can be located on the same plane parallel to the upper end face of the water-cooled copper plate, and also can be located on different planes, that is, the three measuring positions can also be located at different heights of the smelting furnace, and the measuring results can be more accurate due to the points taken at different heights of the smelting furnace.
In this embodiment, preferably, any two elements in the constituent elements of the alloy sample to be smelted are combined into an alloy system, and the alloy system with the corresponding binary phase diagram is screened out, and the eutectoid transformation temperature of the alloy system is obtained through the corresponding binary phase diagram;
and selecting the eutectoid transformation temperature with the minimum value as the atmosphere limit temperature of the hearth through comparison.
Specifically, the limit temperature of the furnace shell can be derived by combining the following equations (1) to (5):
in the formula, tn+1Ultimate temperature (. degree. C.) of the outer shell, q-Total Heat removal (W), an-total heat dissipation factor (W/m)2·K)，tα-ambient temperature (25 ℃);
an＝anR+anC(2)，
in the formula: a isnRRadiation heat dissipation coefficient (W/m)2·K)，anC-coefficient of convective heat dissipation (W/m)2·K)；
In the formula: -blackness factor of the slab radiative heat transfer;
in the formula: a-position coefficient, ξ -wind speed coefficient, u-wind speed (m/s);
λ＝b+(cE-5)*t1(6)
in the formula: lambda-thermal conductivity (W/m.K), t1-hearth (atmosphere) temperature (DEG C), b, c-coefficients, obtaining thermal conductivity coefficients at different temperatures according to furnace shell materials of a smelting furnace, and then performing linear fitting to obtain coefficients b and c;
the obtained atmosphere limit temperature of the hearth and the assumed limit temperature t of the furnace shelln+1Substituting the known data into the formulas (1) to (8), calculating the limit temperature of the furnace shell, and calculatingThe calculated limit temperature of the furnace shell is satisfied when the deviation between the limit temperature of the furnace shell and the assumed limit temperature of the furnace shell is within a predetermined range (the predetermined range is typically 5%).
Based on the derivation process, the alloy sample to be smelted is taken as a titanium-based brazing filler metal cast ingot for illustration, and the common titanium alloy components mainly comprise Ti-Zr-Cu-Ni, wherein Ti and Zr belong to the same group elements, and have similar atomic structures and are infinitely miscible with each other; cu and Ni belong to similar elements in the periodic table, and have similar atomic structures and infinite mutual solubility; the Ti-Zr-Cu-Ni alloy is optimized by taking Ti-Cu, Ti-Ni, Zr-Cu and Zr-Ni binary phase diagrams as the basis, and the ratio of the specific gravity (Ti, Zr): (Cu, Ni) ═ 3: 1, the eutectoid transformation temperatures of the binary phase diagrams are respectively 800 ℃, 765 ℃, 822 ℃ and 845 ℃, and once the atmospheric temperature of the hearth exceeds 765 ℃, the Ti and Ni alloy can generate eutectoid transformation reverse reaction to seriously influence the solidification and cooling process of the cast ingot, so that the atmospheric temperature of the hearth is controlled below 765 ℃, namely 765 ℃ is the atmospheric limit temperature of the hearth, and the method is particularly shown in fig. 2.
The furnace shell of the vacuum smelting furnace is made of 1Cr18Ni9 stainless steel, and the thickness of the furnace shell is 1.0 cm. As shown in FIG. 3, the thermal conductivity (W/m.K) of 1Cr18Ni9 stainless steel in a rolled state at different temperatures is as follows: 20-0.16, 50-0.17, 100-0.18, 200-0.19, 400-0.20, 500-0.22, 600-0.23, 700-0.23, 900-0.25. Obtaining a linear fit equation:
λ＝0.16594+(9.69824E-5)*t1(6)，
the atmospheric limit temperature of the furnace chamber is 765 ℃, and the limit temperature t of the outer furnace shell is assumedn+1Taking 2.2 according to the actual melting environment A, taking 1 according to ξ, taking 0 according to u and taking 0.85, substituting the parameters into the heat transfer coefficient equation (6) to obtain lambda being 0.24W/m.K, and substituting the lambda into the equation (4) to obtain anC＝5.991W/m2K, substituting into formula (3) to obtain anR＝5.786W/m2K, in formula (2) to an＝11.7775W/m2K, the total thermal resistance R obtained by substituting into the formula (7) is 4.252K · m2and/W, the total heat q is 174.036W in the following formula (8). T in the formula (1)n+1Calculated outer at 39.777 ℃Limit temperature t of furnace shelln+1The error of the set limit temperature of the outer furnace shell is 50.279 percent, the difference value is larger, and the temperature t of the outer furnace shell is resetn+1And then calculation is carried out.
The atmospheric limit temperature of the furnace chamber is 765 ℃, and the limit temperature t of the outer furnace shell is assumedn+1Taking 2.2 according to the actual melting environment A, taking 1 according to ξ, taking 0 according to u and taking 0.85, substituting the parameters into the heat transfer coefficient equation (6) to calculate that lambda is 0.24W/m.K, and substituting the lambda into the equation (4) to obtain anC＝4.452W/m2K, bringing into formula (3) to anR＝4.873W/m2K, substituting into formula (2) to obtain an＝9.325W/m2K, the total thermal resistance R is 4.274 K.m2and/W, the total heat q is 173.140W in the following formula (8). T substituted into equation (1)n+1The limit temperature t of the outer shell obtained was calculated at 43.567 ℃n+1The error from the set outer shell temperature was 3.164%, which was acceptable.
Therefore, the temperature t of the vacuum furnace shell is not more than 43.567 ℃ in the vacuum melting process of the titanium-based brazing filler metal cast ingot, once the temperature is higher than the temperature, the atmosphere temperature of the hearth inevitably exceeds the limit temperature 765 ℃, eutectoid transformation reverse reaction can occur on Ti and Ni alloy, and the solidification and cooling process of the cast ingot is seriously influenced.
On the basis of the above-mentioned derivation of the limit temperature of the furnace shell, how to ensure that the atmospheric temperature of the furnace chamber is less than the atmospheric limit temperature of the furnace chamber can be implemented by one or more of the following measures:
reducing the amount of alloy charged into each crucible;
the number of crucibles into which the alloy is put is reduced;
the smelting time of the alloy in each crucible is shortened;
prolonging the next arcing time after each smelting is finished, and starting the next arcing smelting when the temperature of the atmosphere in the hearth is reduced to be less than or equal to the limit temperature of the furnace shell;
repeatedly smelting an alloy sample to be smelted for multiple times, and turning over the alloy to be smelted in the crucible between two adjacent smelting operations;
in the smelting process, operations such as small-current positioning arcing, large-current rapid alloy smelting, small-current crucible reversing and the like are adopted.
Specifically, the following is exemplified:
selecting 3 of 5 copper crucibles in the vacuum non-consumable arc melting furnace, namely correspondingly reducing the number of crucibles in which alloy is put, wherein the total weight of alloy melted by 1 copper crucible each time is 50g, namely correspondingly reducing the amount of alloy put in each crucible, vacuumizing the furnace to 10-2Pa by a three-pole vacuum pump, filling argon gas to wash the furnace for 4 times, vacuumizing to 10-2Pa, and filling argon gas to 0.06MPa again. Before the actual melting, a pure titanium sample was repeatedly melted to further remove oxygen remaining in the atmosphere. The formal arc starting alloy smelting process includes the important steps of small current positioning arc starting, large current fast alloy smelting, small current reversing crucible, etc. and the time for smelting large current alloy is controlled strictly.
After the primary smelting is finished, in order to ensure that the components of the alloy cast ingot are uniform, the sample in the water-cooled copper crucible is repeatedly smelted for 5 times under the action of electromagnetic stirring, and the sample is turned over by using a reverse pulling rod, namely, the alloy to be smelted in the crucible is turned over between two adjacent smelting operations.
Fig. 4 is a macro topography diagram of a titanium-based solder ingot and an ingot after 5 times of smelting provided by the embodiment of the application, and fig. 5 is a microstructure of the titanium-based solder ingot and an ingot core obtained by controlling different temperatures of the vacuum smelting furnace shell. The average values of the furnace case temperatures at 3 before the completion of the melting of the ingots denoted by the reference numerals (a), (b), (c), (d), (e) and (f) were 35.2 ℃, 42.3 ℃, 49.2 ℃, 54.3 ℃, 65.6 ℃ and 80.1 ℃.
From the microstructure, the temperature of the furnace shell is 35.2 ℃, the structure is uniform, and no structure precipitate (solid solution) is seen; when the temperature is raised to 42.3 ℃, the black granular phase is generated in the microstructure, but the whole structure still keeps uniformity; when the temperature is increased to 49.2 ℃, part of tissues separate out dark-colored system solid solution, and the tissues are obviously heterogeneous; the temperature is continuously increased to 54.3 ℃, the size of the solid solution precipitated by the tissue continuously grows, and the tissue area of the solid solution is obviously increased; when the temperature rises to 65.6 ℃, the whole Scanning Electron Microscope (SEM) visual field is completely occupied by the dark solid solution; the dark solid solution size increased significantly when the temperature was increased to 80.1 ℃.
The temperature of the shell of the vacuum furnace is less than or equal to 43.567 ℃, the segregation phenomenon of obvious components is not seen in the ingot casting structure, and the uniformity of the ingot casting structure is good.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
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