阅读说明：本技术 一种用于单晶/定向凝固中频感应加热保温炉装置 (Medium-frequency induction heating holding furnace device for single crystal/directional solidification ) 是由 武周 郑素杰 骆凯伦 杨振宇 骆宇时 唐定中 戴圣龙 于 2021-05-07 设计创作，主要内容包括：本发明公开了一种用于材料单晶/定向凝固生长的中频感应加热保温炉装置,包括碳纤维盖板、碳复合材料挡板、隔热保温材料、石墨套、缠绕在石墨套外围的感应圈,感应圈之间的屏蔽圈,绝缘胶木立柱及上/下区测温热电偶等部分组成。本发明主要解决了单晶/定向凝固过程中感应式加热保温炉分区独立调节,抗磁场干扰、高温度梯度等控制问题。能够与一套可智能调节分区输出的中频电源配合使用,对在单晶/定向凝固过程中的金属熔液实施温度控制,实现高温度梯度场,从而更好地生产制造单晶/定向零件产品。(The invention discloses a medium-frequency induction heating holding furnace device for single crystal/directional solidification growth of a material, which comprises a carbon fiber cover plate, a carbon composite baffle, a heat insulation material, a graphite sleeve, induction coils wound on the periphery of the graphite sleeve, a shielding ring between the induction coils, an insulated bakelite upright column, upper/lower region temperature measuring thermocouples and the like. The invention mainly solves the control problems of independent adjustment of induction heating holding furnace in different areas, magnetic field interference resistance, high temperature gradient and the like in the single crystal/directional solidification process. The device can be matched with a set of intermediate frequency power supply capable of intelligently adjusting output in a partitioning manner, and can be used for controlling the temperature of molten metal in the process of single crystal/directional solidification, so that a high temperature gradient field is realized, and single crystal/directional part products can be better produced and manufactured.)

1. A medium frequency induction heating holding furnace device for material single crystal/directional solidification growth comprises a carbon fiber cover plate, a carbon composite material baffle, a heat insulation material, a graphite sleeve, induction coils wound on the periphery of the graphite sleeve, shielding rings among the induction coils, insulated bakelite upright posts and upper and lower zone temperature thermocouples; the device is characterized in that the graphite sleeve is divided into an upper part and a lower part which are coaxially arranged, the middle part is isolated by a carbon composite material baffle, the corresponding peripheral induction coil is also divided into an upper induction coil and a lower induction coil which are coaxially arranged, and the coaxially arranged induction coil and the graphite sleeve divide the holding furnace device into an upper heating area and a lower heating area; a circle of shielding ring made of water-cooled copper tubes is arranged between the upper induction ring and the lower induction ring and is used for absorbing the induction magnetic fields of the upper isolation region and the lower isolation region, the heights of the upper induction ring and the lower induction ring in the upper isolation region and the lower induction ring in the lower isolation region are consistent with the heights of the graphite sleeves in the upper isolation region and the lower isolation region, and the positions of the shielding rings correspond to the positions of the carbon composite material baffle plates and are consistent with the height of a.

2. The medium frequency induction heating holding furnace device according to claim 1, wherein the upper zone induction coil and the lower zone induction coil are independently placed from top to bottom, two layers of graphite sleeves are coaxially and multiply placed with the induction coils, the two groups of induction coils are working coils, the induction coils are formed by winding hollow copper pipes and are connected with two corresponding groups of water-cooling copper cables in a flange connection sealing mode, the induction coils and the water-cooling copper cables are simultaneously communicated with cooling circulating water and medium frequency alternating current in working, the induction coils are communicated with the medium frequency alternating current to generate an induction magnetic field, and eddy current is generated in the graphite sleeves to radiate heat to the holding furnace;

the water-cooling copper pipe without electricity is arranged between the upper region induction coil and the lower region induction coil layer to serve as a shielding ring, so that an interference magnetic field generated by the upper region induction coil and the lower region induction coil is absorbed and isolated, and the upper region and the lower region can work independently.

3. The holding furnace apparatus according to claim 1, wherein the graphite sleeve in the induction coil receives an induction magnetic force generated by the corresponding induction coil and converts the induction magnetic force into a short-circuit eddy current according to Joule's lawThe heat energy is converted into heat energy to radiate and heat molten steel in the casting mold so as to ensure a directional solidification gradient temperature field in the heat preservation furnace and be used for manufacturing single crystal/directional alloy material products.

4. The holding furnace apparatus according to claim 1, wherein said induction coil is made of a hollow copper tube, and is capable of being energized and cooling water; the shielding ring is not electrified and only water is electrified, the induction ring receives medium-high frequency alternating current to generate induction magnetic lines, the magnetic lines generate eddy currents in the graphite sleeve to enable the material to generate heat, the induction ring and the shielding ring are both made of glass fiber cloth tapes dipped in insulating varnish to wrap the copper pipe, and the outermost layer is integrally brushed with epoxy resin;

four to six insulated bakelite upright posts are arranged on the outermost periphery of the induction coil, and the induction coil and the shielding coil are coaxially and fixedly connected through screws and nuts, so that the coils are stably connected and have good insulation.

5. The holding furnace device according to claim 1, wherein the device is connected with an intelligent intermediate frequency induction power supply capable of distributing power, the intermediate frequency power supply intelligent regulation system can calculate a temperature difference value according to the feedback temperature of the partitioned temperature thermocouple compared with a target set temperature, and transmit and distribute intermediate and high frequency electric energy to the partitioned induction coil according to a PID model regulation control signal, the graphite sleeve in the induction coil converts an induction magnetic field into an induced eddy current, and then generates heat radiation according to the Joule law to heat and preserve heat of the graphite sleeve, so that the partitioned temperature difference gradient control is realized, and the single crystal/directional solidification process of molten metal is completed.

Technical Field

The invention relates to the field of material solidification processing, in particular to a medium-frequency induction heating holding furnace device for material single crystal/directional solidification growth.

Background

Single crystal/directional solidification is a process by which a single crystal or multiple co-directional columnar crystals are directionally grown from a melt from a metal or alloy. The single crystal/directional solidification technology is a key technology for preparing parts of an aircraft engine, and the current international advanced high-performance aircraft engine is manufactured by single crystal/directional solidification of working and guide turbine blades which bear high temperature and high pressure inside. It can be said that the level of manufacture of the single crystal orientation blade affects and determines the quality of the engine.

The directional solidification technology adopts a forced one-dimensional heat dissipation method to directionally carry out the solidification process along the direction of temperature gradient to obtain a directional solidification structure, and the directional solidification technology goes through the development processes of an exothermic casting method (EP), a power reduction method (PD), a high-speed solidification method (HRS), a Liquid Metal Cooling (LMC) method and the like. Currently, the manufacture of single crystal/directionally solidified parts is mainly achieved by the rapid solidification method (HRS).

The induction parameters of the directional solidification technology comprise the temperature gradient GL of the liquid phase at the front edge of the solid-liquid interface and the forward propulsion speed R of the solid-liquid interface in the solidification process. The GL/R value is an important criterion for controlling the stability of a single crystal growth interface, and the directional solidification technology and the device are continuously improved, wherein one of the key technologies aims to improve the temperature gradient GL of a liquid phase at the front edge of a solid-liquid interface so as to achieve the aim of improving the quality and the qualification rate of single crystal part products.

The main equipment of the rapid solidification method HRS is a single crystal directional solidification furnace, when an alloy ingot is cast into a hot casting mold in a heat preservation furnace in an ingot mold chamber, the casting mold is placed on a water-cooled crystallizer, the casting mold is pulled out of an ingot mold heating chamber at a certain speed, and the process must ensure that a higher temperature gradient is formed at a solid/liquid interface, which is the key of the crystallization of a single crystal alloy casting. The molten metal then gradually loses heat in the mold and begins to solidify, and in order to maintain the temperature gradient, it must be thermally radiated by means of a holding furnace in the mold chamber to maintain the temperature gradient throughout the single crystal/directional solidification process. The whole temperature field in the heat preservation furnace is too high, so that the casting mold is easily damaged, and the alloy elements are easily burnt; the whole temperature is too low, and high gradient superheat degree required by the solidification process cannot be formed, so that the solidification forming of the tissue is not facilitated.

The means for ensuring the high temperature gradient is to divide the holding furnace into an upper area and a lower area, and the temperature of the lower area is slightly higher than that of the upper area, so the scheme has good effect on the temperature gradient at the front edge of the solid-liquid interface. The heating elements of the two zones of the holding furnace can be obtained by adopting a graphite or induction method, and most of the holding furnaces of the directional solidification devices adopt graphite heating bodies all the time. The graphite heating body has the advantages of simple control technology, but the high-purity graphite heating body has the defects of low heating speed, lagging thermal effect of a temperature field, high processing cost, short service life, high maintenance cost and the like; the induction heating device has the advantages of high speed of induction heating, high thermal efficiency, convenient disassembly, assembly, maintenance and production cost saving, but the induction heating device is too close to the induction coils of the two temperature areas because the induction coils are coaxially arranged, the induction magnetic fields generated by the upper and lower areas interfere with each other, and the temperature field control problem is difficult to solve all the time.

Disclosure of Invention

The invention aims to provide a coil of a medium-frequency induction holding furnace for single crystal/directional solidification growth of a material, which aims to solve the problem of medium-frequency induction heating of a high-temperature gradient field double-zone holding furnace in a single crystal/directional solidification device provided in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: a medium-frequency induction heating holding furnace device for high-temperature gradient single crystal/directional solidification growth comprises a carbon fiber cover plate, a carbon composite baffle, a heat insulation material, a graphite sleeve, induction coils wound on the periphery of the graphite sleeve, a shielding ring between the induction coils, an insulated bakelite upright post, an upper-region temperature measuring thermocouple and a lower-region temperature measuring thermocouple, wherein the graphite sleeve is divided into an upper part and a lower part which are coaxially arranged, the middle part is isolated by the carbon composite baffle, the induction coil corresponding to the periphery is also divided into an upper area and a lower area which are coaxially arranged, a shielding coil made of water-cooled copper pipes is arranged between the upper induction coil and the lower induction coil, the device has the functions of absorbing and isolating the induction magnetic fields of the upper and lower regions, the height of the induction coil of the upper and lower regions is consistent with that of the graphite sleeve of the upper and lower regions in the corresponding inner part, and the position of the shielding ring corresponds to that of the carbon composite material baffle and is consistent with that of a molten metal interface in the single crystal/directional solidification process.

Preferably, the induction coil of upper region and lower district induction coil are from the top down independently set up in about two sets of graphite cover outside, two sets of induction coils and graphite cover are coaxial to be placed, these two sets of induction coils are the work circle, pass through flange mouth sealing mode with two sets of water-cooling copper cables that correspond and connect the water and electricity, the induction coil leads to cooling cycle water and intermediate frequency alternating current simultaneously with the water and electricity cable in work, the copper circle that sets up not circular telegram between induction coil of upper region and lower district induction coil layer is as the shielding circle, go to absorb and keep apart the interference magnetic field that the induction coil of upper and lower district produced, guarantee upper and lower district independent work.

Preferably, the graphite sleeve in the upper and lower working rings is converted into a short-circuit eddy current after receiving the induction magnetic force line of the corresponding ring according to Joule's lawThe heat energy is converted into heat energy to radiate and heat molten steel in the casting mold so as to ensure a directional solidification gradient temperature field in the heat preservation furnace and be used for manufacturing single crystal/directional alloy material products.

Preferably, the induction coils are made of hollow copper pipes, medium-high frequency alternating current and cooling water are supplied, a circle of shielding coil which is not supplied with electricity but only supplied with cooling water is arranged between the induction coils, the induction coils are also made of the hollow copper pipes, the graphite sleeves in the induction coils convert an induction magnetic field into induced eddy currents, and when induction magnetic lines of the induction coils interfere with each other at the upper and lower regions, most of the redundant magnetic lines of force are absorbed and consumed by the shielding coils, so that the isolation effect is achieved, and the upper and lower regions can independently work and control.

Preferably, the induction coil and the shielding coil are both made of glass fiber cloth tapes dipped in insulating paint to wrap the copper tubes, and epoxy resin is brushed on the outermost layer of the induction coil and the outermost layer of the shielding coil for insulating treatment. The induction coil and the shielding coil are coaxially and fixedly connected by the outermost insulated bakelite upright post through screws and nuts, so that the coils are stably connected and have good insulation.

Preferably, the induction coils are connected with a medium-frequency induction power supply capable of intelligently distributing power, when molten steel is in the solidification process of a casting mold, the intelligent medium-frequency power supply adjusting system intelligently distributes output electric energy to each group of induction coils through temperature setting of subareas, thermocouple temperature difference feedback and parameter calculation control signals of a PID model, so that subarea temperature difference gradient control is realized, and the single crystal/directional solidification process is well completed.

The device can be divided into two or more groups according to the number of the graphite sleeves, and can be matched with a set of intermediate frequency power supply capable of intelligently adjusting partition output for use, the temperature of the induction heating holding furnace is set and fed back, the power distribution is intelligently adjusted and optimized, the temperature of molten metal in the single crystal/directional solidification process is controlled, a high temperature gradient field is realized, and the single crystal/directional part product is better produced and manufactured. The invention solves the control problems of independent adjustment of induction heating holding furnace in different areas, magnetic field interference resistance, high temperature gradient and the like in the single crystal/directional solidification process. The device also has the advantages of high heating rate, high thermal efficiency, large temperature gradient, simple and reliable structure, low maintenance and overhaul cost and the like.

Drawings

FIG. 1 is a schematic structural diagram of a medium frequency induction heating holding furnace device for single crystal/directional solidification according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

Referring to fig. 1, a device for single crystal/directional solidification medium frequency induction heating holding furnace includes a graphite sleeve 1, a heat insulation material 2, an upper zone induction coil 3, an upper zone induction coil water and electricity inlet 4, an upper zone temperature thermocouple 5, a shielding coil 6, a shielding coil water inlet 7, an induction coil water and electricity inlet 8, a temperature thermocouple 9, a lower zone induction coil 10, an induction coil water and electricity outlet 11, a water cooling ring 12, a water cooling crystallizer 13, a casting mold 14, a shielding coil water outlet 15, an induction coil water and electricity outlet 16, a carbon composite baffle 17, an upper zone solidification interface 18, a lower zone solidification interface 19, an insulated bakelite upright column and a carbon fiber cover plate 20.

Graphite sleeve 1 is divided into upper and lower region two parts, coaxial placing, the centre is kept apart with carbon composite baffle 17, it also divide into upper region and lower region two parts coaxial placing to correspond outlying induction coil, there is one turn of shielding circle 6 of making with water-cooling copper pipe between the upper and lower induction coil, the induction field of upper and lower region is kept apart in the effect for absorbing, upper and lower district induction coil height is highly unanimous with corresponding inside upper and lower region graphite sleeve, 6 positions of shielding circle correspond the carbon fiber baffle position, with carry out the single crystal/the molten metal interface height unanimity of directional solidification process.

Go up district induction coil 3 and lower district induction coil 10 for from the top down independently set up in the top down two sets of graphite cover 1 outside, two sets of induction coils and graphite cover are coaxial to be placed, these two sets of induction coils are the work circle, pass through flange mouth sealing mode with two sets of water-cooling copper cables that correspond and connect the water and electricity, the induction coil leads to cooling cycle water and intermediate frequency alternating current simultaneously with water-cooling copper cable in work, it is as shielding circle 6 to set up the copper circle of not circular telegram between 10 layers of induction coil 3 and lower district induction coil, go to absorb and keep apart the interference magnetic field that the district induction coil produced about, guarantee upper and lower district independent work.

The graphite sleeve in the upper and lower working rings is converted into a short-circuit eddy current after receiving the induction magnetic force line of the corresponding ring, and the short-circuit eddy current is converted according to Joule's lawThe heat energy is converted into heat energy to radiate and heat molten steel in the casting mold so as to ensure a directional solidification gradient temperature field in the heat preservation furnace and be used for manufacturing single crystal/directional alloy material products.

The induction coil is made of hollow copper pipes, medium-high frequency alternating current and cooling water are supplied, a circle of shielding ring which is not electrified but only is supplied with the cooling water is arranged between the induction coils, the induction coil is also made of the hollow copper pipes, the induction coil receives the medium-high frequency alternating current to generate induction magnetic lines to heat the magnetic conduction conducting material in the induction coil to generate heat, when the induction magnetic lines of the induction coil interfere with each other at the upper and lower regions, the redundant magnetic lines of force are absorbed and consumed by the shielding ring, the isolation effect is achieved, and the purpose of independent work and control of the upper and lower.

The induction coil and the shielding coil are both made of glass fiber cloth belts dipped in insulating varnish to wrap copper pipes, and epoxy resin is brushed on the outmost layer of the induction coil and the shielding coil to be used for insulating treatment. The induction coil and the shielding coil are coaxially and fixedly connected by the outermost insulated bakelite upright post through screws and nuts, so that the coils are stably connected and have good insulation.

The induction coils are connected with a medium-frequency induction power supply capable of intelligently distributing power, when molten steel is in the solidification process of a casting mold, the intelligent medium-frequency power supply adjusting system intelligently distributes output electric energy to each group of induction coils through temperature setting of subareas, temperature difference feedback of upper and lower temperature thermocouples and parameter calculation control signals of a PID model, so that subarea temperature difference gradient control is realized, and the single crystal/directional solidification process is well completed.

In conclusion, the device for the single crystal/directional solidification medium-frequency induction heating holding furnace solves the control problems of independent adjustment of the induction heating holding furnace in different areas, magnetic field interference resistance, high temperature gradient and the like in the single crystal/directional solidification process. The device also has the advantages of high heating rate, high thermal efficiency, large temperature gradient, simple and reliable structure, low maintenance and overhaul cost and the like. The device can be matched with a set of intermediate frequency power supply capable of intelligently adjusting output in a partitioning mode, power output is distributed according to intelligent temperature adjustment of a required process, and a high-temperature gradient field required in a single crystal/directional solidification process is guaranteed. Thereby better producing a single crystal/oriented parts product.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.