JP2000319721A - Ceramic tube, and induction heating furnace using the same - Google Patents
Ceramic tube, and induction heating furnace using the sameInfo
- Publication number
- JP2000319721A JP2000319721A JP11126870A JP12687099A JP2000319721A JP 2000319721 A JP2000319721 A JP 2000319721A JP 11126870 A JP11126870 A JP 11126870A JP 12687099 A JP12687099 A JP 12687099A JP 2000319721 A JP2000319721 A JP 2000319721A
- Authority
- JP
- Japan
- Prior art keywords
- tube
- ceramic
- furnace
- induction heating
- heating furnace
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Landscapes
- Forging (AREA)
- Ceramic Products (AREA)
- Furnace Details (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】 本発明は、自動車、建設機
械、電機製品、農業機械等の各種部品を、例えば鍛造
（塑性）加工によって製造する際に、被加熱材であるビ
レット材等の鋼材を加熱するために使用される誘導加熱
炉に関する。BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing various parts such as automobiles, construction machines, electric products, and agricultural machines by, for example, forging (plasticity) processing. The present invention relates to an induction heating furnace used for heating.
【０００２】[0002]
【従来の技術】 各種機械部品を温熱間鍛造加工によっ
て製造する際には、被加熱材であるビレット材が、予
め、加熱炉によって加熱された後に、鍛造加工されるよ
うになっている。このような鍛造加工用加熱炉として
は、燃焼式加熱炉に替わって、誘導加熱炉が普及してい
る。誘導加熱炉は、ビレット材が搬送される炉心管にコ
イルを巻回した構造をとり、当該コイルに通電すること
によって、炉心管内を搬送されるビレット材が電磁誘導
加熱される仕組みとなっている。2. Description of the Related Art When manufacturing various mechanical parts by hot forging, a billet material to be heated is forged after being heated in advance by a heating furnace. As such a forging heating furnace, an induction heating furnace is widely used instead of a combustion-type heating furnace. The induction heating furnace has a structure in which a coil is wound around a furnace tube through which the billet material is conveyed, and the coil is energized to electromagnetically heat the billet material conveyed in the furnace tube. .
【０００３】 誘導加熱炉の炉心管は、目的に応じて、
実公平2-4120号公報、実公昭62-13722号公報に開示され
たような単管構造、特開平10-272534号公報に開示され
たような二重管構造等、種々の形状のものが用いられる
が、これらの炉心管を構成する材質としては、熱効率を
向上させ、強度を確保する観点から、高熱伝導率、高強
度、高輻射率を有し、アルカリ、アルミニウム、炭酸ガ
ス、酸化雰囲気等に対する耐磨耗性に優れる、炭化珪素
質の耐火セラミックを使用することが好ましいとされて
いる（特開平10-272534号公報）。[0003] The furnace tube of the induction heating furnace is, depending on the purpose,
Japanese Utility Model Publication No. 2-4120, a single-pipe structure as disclosed in Japanese Utility Model Publication No. 62-13722, a double-pipe structure as disclosed in JP-A-10-272534, and various shapes. It is used, but from the viewpoint of improving thermal efficiency and securing strength, it has high thermal conductivity, high strength, high emissivity, and alkali, aluminum, carbon dioxide gas, oxidizing atmosphere. It is said that it is preferable to use a silicon carbide refractory ceramic excellent in abrasion resistance against the like (Japanese Patent Application Laid-Open No. 10-272534).
【０００４】[0004]
【発明が解決しようとする課題】 しかしながら、炉心
管材料として炭化珪素質の耐火セラミックを用いた場合
でも、炉心管の熱特性が充分でないことに起因して加
熱初期に不良が発生したり、炉心管の耐食性、対衝撃
性が不足しているために炉心管が腐食し、或いは破損す
る等の問題が生じる場合があり、未だ炉心管を構成する
材料としての必要条件を充分に満足しているとは言えな
かった。However, even when a silicon carbide refractory ceramic is used as a material for the core tube, a defect occurs at an early stage of heating due to insufficient thermal characteristics of the core tube, Insufficient corrosion resistance and impact resistance of the tube may cause problems such as corrosion or breakage of the core tube, and still sufficiently satisfy the requirements as a material constituting the core tube. I couldn't say.
【０００５】 本発明は、このような従来技術の問題を
解決するためのものであって、その目的とするところ
は、炉心管材料として充分な熱特性を有し、耐食性、耐
衝撃性が高いセラミックチューブ、及び加熱初期に不良
が発生し難く、エネルギーのロスが少ない誘導加熱炉を
提供することにある。The present invention is intended to solve such problems of the prior art, and has as its object to have sufficient thermal properties as a core tube material and to have high corrosion resistance and impact resistance. An object of the present invention is to provide a ceramic tube and an induction heating furnace in which a defect is hardly generated in an early stage of heating and energy loss is small.
【０００６】[0006]
【課題を解決するための手段】 本発明者らが上記従来
技術の問題点について鋭意検討した結果、比熱、熱伝導
率、見掛け気孔率、ヤング率の４特性が特定の範囲内に
あるセラミックが炉心管材料としての必要条件を十分満
足することを見出して本発明を完成した。Means for Solving the Problems As a result of the present inventors diligently examining the above-mentioned problems of the prior art, it has been found that ceramics having four characteristics of specific heat, thermal conductivity, apparent porosity, and Young's modulus are within specific ranges. The present inventors have found that the requirements for a furnace tube material are sufficiently satisfied, and completed the present invention.
【０００７】 即ち、本発明によれば、誘導加熱炉の炉
心管を構成するためのセラミックチューブであって、比
熱が２ｋＪ／ｋｇ・Ｋ以下、熱伝導率が７５Ｗ／ｍ・Ｋ
以上、見掛け気孔率が２％以下、ヤング率が１５０ＧＮ
／ｍ2以上であるセラミックからなることを特徴とする
セラミックチューブが提供される。本発明のセラミック
チューブは、金属Ｓｉ含有量が２〜３５重量％のＳｉ−
ＳｉＣからなるものであることが好ましい。That is, according to the present invention, there is provided a ceramic tube for constituting a furnace tube of an induction heating furnace, having a specific heat of 2 kJ / kg · K or less and a thermal conductivity of 75 W / m · K.
As described above, the apparent porosity is 2% or less, and the Young's modulus is 150 GN.
/ M 2 or more, a ceramic tube comprising a ceramic is provided. The ceramic tube of the present invention has a metal content of 2 to 35% by weight of Si-
It is preferably made of SiC.
【０００８】 更に、本発明によれば上記のセラミック
チューブにより炉心管を構成したことを特徴とする誘導
加熱炉が提供される。Further, according to the present invention, there is provided an induction heating furnace characterized in that a furnace tube is constituted by the above ceramic tube.
【０００９】[0009]
【発明の実施の形態】 以下、誘導加熱炉の一般的な構
成について図面を参照しながら概説した上で、本発明の
セラミックチューブについて詳細に説明する。但し、本
発明は図示の実施例に限定されるものではない。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a general configuration of an induction heating furnace will be outlined with reference to the drawings, and then a ceramic tube of the present invention will be described in detail. However, the present invention is not limited to the illustrated embodiment.
【００１０】 図１は、誘導加熱炉の一般的な構成を示
す縦断面図である。誘導加熱炉は、炉心管内部を電磁誘
導により加熱する加熱炉であって、例えば円筒状のビレ
ット材等を鍛造加工するために用いられるものである。FIG. 1 is a longitudinal sectional view showing a general configuration of an induction heating furnace. The induction heating furnace is a heating furnace that heats the inside of a furnace tube by electromagnetic induction, and is used, for example, for forging a cylindrical billet material or the like.
【００１１】 図示の誘導加熱炉は、炉心管１１を外殻
１４で固定してなる複数の加熱ブロック１０からなり、
各加熱ブロック１０は、ビレット材２０を所定温度に加
熱するために必要な長さになるように、所定の個数が並
列されている。また、各加熱ブロック１０は、ビレット
材２０を連続的に送り込めるように炉心管１１開口部が
一致するように、水平方向に並列されている。The induction heating furnace shown in the figure comprises a plurality of heating blocks 10 each having a furnace tube 11 fixed by an outer shell 14,
A predetermined number of the heating blocks 10 are arranged in parallel so as to have a length necessary for heating the billet material 20 to a predetermined temperature. The heating blocks 10 are arranged in a horizontal direction so that the openings of the core tubes 11 coincide with each other so that the billet material 20 can be continuously fed.
【００１２】 炉心管１１は、図示の如くビレット材２
０が送り込まれる側の開口端にフランジ部１１ｃが設け
られる場合もあるが、フランジ部１１ｃ以外は一定の厚
さを有する管状構造になっている。また、炉心管１１の
外周面は、全体にわたって、断熱材１２によって覆われ
ている。The furnace tube 11 is made of a billet material 2 as shown in the figure.
In some cases, a flange portion 11c is provided at the opening end on the side into which 0 is fed, but the portion other than the flange portion 11c has a tubular structure having a certain thickness. Further, the outer peripheral surface of the furnace tube 11 is entirely covered with a heat insulating material 12.
【００１３】 炉心管１１には、断熱材１２を介して銅
製のコイル導管１３が巻回されている。このコイル導管
１３は、断面四角形の中空パイプ状になっており、その
外周面は絶縁材によって被覆されている。更に、コイル
導管１３の内部には、冷却水が通流されるようになって
いる。A coil tube 13 made of copper is wound around the furnace tube 11 via a heat insulating material 12. The coil conduit 13 has a hollow pipe shape with a rectangular cross section, and its outer peripheral surface is covered with an insulating material. Further, cooling water flows through the inside of the coil conduit 13.
【００１４】 炉心管１１は、ノンアスベスト等の耐熱
材によって構成された外殻１４の中心部に、水平状態に
架設されて、各端部がアルミナセメント１５によって、
外殻１４に固定されている。The furnace tube 11 is installed horizontally in the center of an outer shell 14 made of a heat-resistant material such as non-asbestos, and each end is made of alumina cement 15.
It is fixed to the outer shell 14.
【００１５】 誘導加熱炉においては、コイル導管１３
への通電による電磁誘導によって炉心管１１内部が加熱
される。従って、誘導加熱炉入口側の炉心管１１開口部
からプッシャー、ピンチローラー等によって炉心管１１
内にビレット材２０を連続的に送り込むことにより、ビ
レット材２０が、各加熱ブロック１０の炉心管１１内を
順番に通過し、順次加熱され、最後の加熱ブロック１０
における炉心管１１内では、１２００℃程度の高温に加
熱される。In the induction heating furnace, the coil conduit 13
The inside of the furnace tube 11 is heated by electromagnetic induction due to power supply to the furnace core 11. Accordingly, the furnace tube 11 is opened from the opening of the furnace tube 11 on the inlet side of the induction heating furnace by a pusher, a pinch roller or the like.
By continuously feeding the billet material 20 into the inside, the billet material 20 sequentially passes through the core tube 11 of each heating block 10 and is sequentially heated, so that the last heating block 10
Is heated to a high temperature of about 1200.degree.
【００１６】 本発明のセラミックチューブは、比熱、
熱伝導率、見掛け気孔率、ヤング率の４特性が特定の範
囲内にあるセラミックからなることを特徴とする。本発
明のセラミックチューブは、炉心管材料として充分な熱
特性を有し、耐食性、耐衝撃性も高いため、上述のよう
な誘導加熱炉の炉心管として好適に用いることができ
る。また、本発明のセラミックチューブを炉心管として
用いた誘導加熱炉は、加熱初期に不良が発生し難く、エ
ネルギーのロスも少なくすることができる。以下、詳細
に説明する。The ceramic tube of the present invention has a specific heat,
It is characterized by being made of a ceramic having four characteristics of thermal conductivity, apparent porosity and Young's modulus within a specific range. Since the ceramic tube of the present invention has sufficient thermal characteristics as a furnace tube material, and has high corrosion resistance and impact resistance, it can be suitably used as a furnace tube of the above-described induction heating furnace. In addition, in the induction heating furnace using the ceramic tube of the present invention as a furnace tube, defects are unlikely to occur in the early stage of heating, and energy loss can be reduced. The details will be described below.
【００１７】 本発明のセラミックチューブを構成する
セラミックは以下に掲げる４つの特性を備えていること
が必要である。第１には、比熱が低いセラミック、具体
的には比熱が２ｋＪ／ｋｇ・Ｋ以下のセラミックである
ことが必要である。このようなセラミックは、炉心管の
初期加熱が早めることができ、加熱初期に発生する不良
を防止できるとともにエネルギーのロスを減少させるこ
とができるからである。The ceramic constituting the ceramic tube of the present invention needs to have the following four characteristics. First, it is necessary that the ceramic has a low specific heat, specifically, a ceramic having a specific heat of 2 kJ / kg · K or less. This is because such ceramics can speed up the initial heating of the furnace tube, prevent defects occurring at the beginning of heating, and reduce energy loss.
【００１８】 第２には、熱伝導率が高いセラミック、
具体的には熱伝導率が５０Ｗ／ｍ・Ｋ以上のセラミック
であることが必要である。このようなセラミックはチュ
ーブ内で熱が拡散し易いため、加熱開始時やビレット入
口側等の温度差がつきやすい部分におけるチューブのス
ポーリングによる破損を防止できるとともに、局部的な
オーバーヒート状態を生じても速やかに均熱状態に戻る
ことからチューブ表面の劣化を防止することができるか
らである。Second, a ceramic having high thermal conductivity,
Specifically, the ceramic must have a thermal conductivity of 50 W / m · K or more. Since such a ceramic easily diffuses heat in the tube, it can prevent breakage due to spalling of the tube at a portion where a temperature difference is likely to be generated, such as at the start of heating or at the billet inlet side, and cause a local overheating state. This is also because the temperature is quickly returned to the soaking state, so that deterioration of the tube surface can be prevented.
【００１９】 第３には、見掛け気孔率が低いセラミッ
ク、具体的には見掛け気孔率が２％以下のセラミックで
あることが必要である。このようなセラミックは、炉内
雰囲気、或いはビレット材から発生するスラグ等が炉心
管内部に浸透し難くなるため、高い耐食性を得ることが
できるからである。Third, the ceramic must have a low apparent porosity, specifically a ceramic having an apparent porosity of 2% or less. This is because such a ceramic makes it difficult for the slag or the like generated from the billet material to penetrate into the furnace core tube, so that high corrosion resistance can be obtained.
【００２０】 第４には、ヤング率が高いセラミック、
具体的にはヤング率が１５０ＧＮ／ｍ2以上のセラミッ
クであることが必要である。ビレット材が炉心管内を通
過する際には、炉心管に対して強い衝撃が加わるが、ヤ
ング率が高いセラミックであれば高い耐衝撃性を得るこ
とができるからである。Fourth, a ceramic having a high Young's modulus,
Specifically, the ceramic must have a Young's modulus of 150 GN / m 2 or more. When the billet material passes through the furnace tube, a strong impact is applied to the furnace tube, but if the ceramic has a high Young's modulus, high impact resistance can be obtained.
【００２１】 上述の通り、本発明のセラミックチュー
ブを構成するセラミックは、上記の４特性を満たすセラ
ミックである限りにおいて、従来用いていたＳｉＣに限
定されない。一方、上記の４特性を満たさないものにつ
いては、たとえＳｉＣであっても本発明の効果を得るこ
とができない。以下、上記４特性を満たすセラミックの
具体例を挙げる。As described above, the ceramic constituting the ceramic tube of the present invention is not limited to the conventionally used SiC as long as the ceramic satisfies the above four characteristics. On the other hand, if the above four characteristics are not satisfied, the effect of the present invention cannot be obtained even if the material is SiC. Hereinafter, specific examples of ceramics satisfying the above four characteristics will be described.
【００２２】Ｓｉ−ＳｉＣ 一般にＳｉ−ＳｉＣとは金属ＳｉとＳｉＣを構成成分と
して含む焼結体を総称するが、上記４特性を満たすＳｉ
−ＳｉＣとしては、本出願人が特開平5-270917号公報で
開示した、ＳｉＣ粉体、黒煙粉、有機質バインダー及
び、水分又は有機溶剤を含有してなる成形用原料を成形
し、当該成形体を金属Ｓｉ雰囲気で、かつ減圧の不活性
ガス雰囲気又は真空中において、１３５０〜２５００℃
で焼成する方法により製造してなるＳｉ−ＳｉＣ焼結体
が挙げられる。Si--SiC Generally, Si--SiC is a general term for a sintered body containing metallic Si and SiC as constituents.
As SiC, a molding raw material containing SiC powder, black smoke powder, an organic binder, and water or an organic solvent, disclosed by the present applicant in Japanese Patent Application Laid-Open No. H5-270917, is formed. 1350-2500 ° C. in a metal Si atmosphere and a reduced pressure inert gas atmosphere or vacuum
And a sintered body of Si-SiC produced by a method of baking.
【００２３】 上記のＳｉ−ＳｉＣ中でも、金属Ｓｉ含
有量が２〜３５重量％のＳｉ−ＳｉＣであることが好ま
しい。金属Ｓｉが２重量％未満では見掛け気孔率が本発
明の範囲より高くなったり、或いはヤング率が本発明の
範囲より低下する場合があり、３５重量％超では比熱が
本発明の範囲より大きくなるおそれがあるからである。Among the above-mentioned Si—SiC, it is preferable that the metal Si content be 2 to 35% by weight. If the content of metallic Si is less than 2% by weight, the apparent porosity may be higher than the range of the present invention, or the Young's modulus may be lower than the range of the present invention. If it exceeds 35% by weight, the specific heat becomes larger than the range of the present invention. This is because there is a fear.
【００２４】Ｓｉ3Ｎ4 上記４特性を満たすＳｉ3Ｎ4としては、例えばＳｉ3Ｎ4
原料粉末に、イットリア等の焼結助剤を添加混合して成
形後、焼成して得られるＳｉ3Ｎ4焼結体が挙げられる。The Si 3 N 4 as the Si 3 N 4 which satisfies the above four properties, for example, Si 3 N 4
A sintering aid such as yttria is added to the raw material powder, mixed, molded, and then fired to obtain a Si 3 N 4 sintered body.
【００２５】 以上説明したように、上記４特性を満た
すセラミックで構成されたセラミックチューブは、炉心
管材料として充分な熱特性を有し、耐食性、耐衝撃性も
高いため、上述のような誘導加熱炉の炉心管として好適
に用いることができる。また、本発明のセラミックチュ
ーブを炉心管として用いた誘導加熱炉は、加熱初期に不
良が発生し難く、エネルギーのロスも少なくすることが
できる。As described above, a ceramic tube made of ceramic satisfying the above four characteristics has sufficient thermal characteristics as a furnace tube material, and has high corrosion resistance and impact resistance. It can be suitably used as a furnace core tube of a furnace. In addition, in the induction heating furnace using the ceramic tube of the present invention as a furnace tube, defects are unlikely to occur in the early stage of heating, and energy loss can be reduced.
【００２６】 なお、本発明の誘導加熱炉は、上記４特
性を満たすセラミックで構成されたセラミックチューブ
で炉心管を構成している限りにおいて、炉心管の構造は
特に限定されない。即ち、本発明のセラミックチューブ
は、実公平2-4120号公報、実公昭62-13722号公報に開示
されたような単管構造、特開平10-272534号公報に開示
されたような二重管構造等、種々の形状の炉心管の材料
として好適に用いることができる。The structure of the furnace tube of the induction heating furnace of the present invention is not particularly limited as long as the furnace tube is formed of a ceramic tube made of ceramic satisfying the above four characteristics. That is, the ceramic tube of the present invention has a single tube structure as disclosed in Japanese Utility Model Publication No. 2-4120, Japanese Utility Model Publication No. 62-13722, and a double tube as disclosed in Japanese Patent Application Laid-Open No. 10-272534. It can be suitably used as a material of a furnace tube having various shapes such as a structure.
【００２７】[0027]
【実施例】 以下、本発明のセラミックチューブについ
て、種々の特性を有するセラミックからなるセラミック
チューブを、図１に示す誘導加熱炉の炉心管とした実施
例により更に詳細に説明する。但し、本発明はこれらの
実施例に限定されるものではない。EXAMPLES Hereinafter, the ceramic tube of the present invention will be described in more detail with reference to an example in which a ceramic tube made of ceramic having various characteristics is used as a core tube of an induction heating furnace shown in FIG. However, the present invention is not limited to these examples.
【００２８】（１）セラミックチューブの材質 セラミックチューブの材質としては、ムライト、Ｓｉ3
Ｎ4結合ＳｉＣ、Ｓｉ3Ｎ4、Ｓｉ−ＳｉＣのいずれかを
使用した。これらの材質を使用した場合の製造方法を以
下に示すとともに、製造されたセラミックチューブ（以
下、「評価試験体」という。）の特性評価結果を表１に
示す。(1) Material of ceramic tube The material of the ceramic tube is mullite, Si 3
N 4 bond SiC, using either Si 3 N 4, Si-SiC . The manufacturing method using these materials is shown below, and the characteristics evaluation results of the manufactured ceramic tubes (hereinafter referred to as “evaluation test pieces”) are shown in Table 1.
【００２９】ムライト：最大粒径１５０μｍの骨材と
なるアンダルサイト６０重量％、微粉の粘土１５重量％
及びアルミナ２５重量％からなる混合物１００重量％に
対し、３０重量％の水を添加しポットミルで８時間混合
後、更に０．５重量％のバインダを添加してスラリーを
作製し、鋳込み成形により成形体を得た。当該成形体は
乾燥後、大気雰囲気下、１４５０℃で３時間焼成して評
価試験体とした。Mullite: 60% by weight of andalusite as aggregate having a maximum particle size of 150 μm, 15% by weight of fine clay
30% by weight of water was added to a mixture of 100% by weight of alumina and 25% by weight of alumina, and the mixture was mixed for 8 hours by a pot mill. I got a body. After drying, the formed body was fired at 1450 ° C. for 3 hours in an air atmosphere to obtain an evaluation test body.
【００３０】Ｓｉ3Ｎ4結合ＳｉＣ：最大粒径１５０μ
ｍの骨材となるＳｉＣ４５重量％、粒径４４μｍ以下の
微粉のＳｉＣ４０重量％及び金属Ｓｉ１５重量％からな
る混合物１００重量％に対し、２０重量％の水を添加し
ポットミルで８時間混合後、更に０．５重量％のバイン
ダを添加してスラリーを作製し、鋳込み成形により成形
体を得た。当該成形体は乾燥後、窒素雰囲気下、１４０
０℃で５時間焼成して評価試験体とした。Si 3 N 4 bonded SiC: maximum particle size 150 μm
20% by weight of water was added to 100% by weight of a mixture of 45% by weight of SiC serving as an aggregate of m, 40% by weight of fine powder having a particle size of 44 μm or less, and 15% by weight of metal Si, and mixed for 8 hours by a pot mill. A slurry was prepared by adding 0.5% by weight of a binder, and a molded product was obtained by casting. The molded body is dried, and then dried under a nitrogen atmosphere.
It was fired at 0 ° C. for 5 hours to obtain an evaluation test body.
【００３１】Ｓｉ3Ｎ4：平均粒径１０μｍのＳｉ3Ｎ4
９５重量％、焼結助剤のＹ2Ｏ3５重量％からなる混合物
１００重量％に対し、３０重量％の水を添加しポットミ
ルで８時間混合してスラリーを作製した。当該スラリー
は鋳込み成形、ＣＩＰ処理を施すことにより成形体と
し、窒素雰囲気下、１９００℃で焼成して評価試験体と
した。The Si 3 N 4: the average particle size of 10 [mu] m Si 3 N 4
95 wt%, relative to the mixture 100 weight% consisting of Y 2 O 3 5 wt% of the sintering aid to prepare a slurry by mixing 8 hours by adding 30 wt% of water pot mill. The slurry was cast and subjected to CIP treatment to form a molded body, which was fired at 1900 ° C. in a nitrogen atmosphere to obtain an evaluation test body.
【００３２】Ｓｉ−ＳｉＣ：最大粒径１５０μｍの骨
材となるＳｉＣ６５重量％、平均粒径１０μｍの微粉の
ＳｉＣ３０重量％からなる混合物９５重量％に対し、平
均粒径１２μｍの黒鉛粉、有機バインダ、平均粒径５０
０μｍの増孔材、水を添加し混合した後、鋳込み成形に
より成形体を得た。当該成形体は乾燥後、金属Ｓｉ雰囲
気で、かつ、真空中において、１６５０℃で焼成するこ
とにより金属Ｓｉを含浸させ、評価試験体とした。な
お、金属Ｓｉ含有量は金属Ｓｉ、黒鉛粉、増孔剤の添加
量により制御した。Si—SiC: A graphite powder having an average particle size of 12 μm, an organic binder, and a 95% by weight mixture of 65% by weight of SiC serving as an aggregate having a maximum particle size of 150 μm and 30% by weight of fine powder having an average particle size of 10 μm. Average particle size 50
After adding and mixing a 0 μm pore-forming material and water, a molded product was obtained by casting. After drying, the formed body was impregnated with metal Si by firing at 1650 ° C. in a metal Si atmosphere and in a vacuum to obtain an evaluation test body. The content of metal Si was controlled by the amounts of metal Si, graphite powder, and a pore-forming agent.
【００３３】[0033]
【表１】 [Table 1]
【００３４】（２）炉心管構造 実施例、比較例においては、前記の評価試験体を図２に
示す構造の炉心管に構成した。炉心管１１は、内部管体
１１ｂと外部管体１１ａとからなる二重管構造とした。
内部管体１１ｂは断面六角形の筒状体を二等分した形状
の下部半体と、断面正十二角形の筒状体を二等分した形
状の上部半体とを当接してなる長さ７００ｍｍの中空管
状に構成した。(2) Furnace tube structure In the examples and comparative examples, the above-mentioned test specimens were constructed as a furnace tube having a structure shown in FIG. The furnace tube 11 has a double tube structure including an inner tube 11b and an outer tube 11a.
The inner tubular body 11b is formed by abutting a lower half having a shape obtained by bisecting a cylindrical body having a hexagonal cross section and an upper half having a shape obtained by bisecting a cylindrical body having a regular dodecagonal cross section. It was configured as a hollow tube having a length of 700 mm.
【００３５】 上部半体の厚さは４ｍｍ、下部半体の厚
さは６ｍｍとし、下部半体よりも上部半体を薄く構成し
た。外部管体１１ａは外径１２０ｍｍ、内径１００ｍ
ｍ、厚さ１０ｍｍの中空円筒状に構成した。The thickness of the upper half was 4 mm, the thickness of the lower half was 6 mm, and the upper half was configured to be thinner than the lower half. The outer tube 11a has an outer diameter of 120 mm and an inner diameter of 100 m
m, a hollow cylindrical shape having a thickness of 10 mm.
【００３６】（３）評価方法 初期加熱効率については、実施例、比較例の炉心管を図
１の誘導加熱炉に配設し、常温から運転温度の１２５０
℃まで昇温する際に、ビレット材−炉心管接触部Ａ点が
運転温度に達するまでの時間ｔ1（秒）と、前記Ａ点が
運転温度に達した後、前記Ａ点、上部管体と下部管体と
の接触部Ｂ点、上部管体最上部Ｃ点の温度差Δｔが５℃
以内となるまでの時間ｔ2（秒）とによって評価した。(3) Evaluation method Regarding the initial heating efficiency, the furnace tubes of the examples and the comparative examples were installed in the induction heating furnace of FIG.
When the temperature rises to 0 ° C., the time t 1 (second) until the billet material-core tube contact point A reaches the operating temperature, and after the point A reaches the operating temperature, the point A and the upper tube The temperature difference Δt between the point B at the point of contact between the tube and the lower tube and the point C at the top of the upper tube is 5 ° C.
The evaluation was made based on the time t 2 (second) until the time was within.
【００３７】 耐食性については、５０ｍｍ角×厚さ１
０ｍｍのテストピース上に１ｇのスラグを載せた状態
で、１２５０℃で５０時間保持した後、図３に示す如く
スラグ載置面を厚さ方向に切断し、侵食層とスラグ浸透
層の厚みを測定することにより評価した。Regarding the corrosion resistance, 50 mm square × thickness 1
After holding at 1250 ° C. for 50 hours with 1 g of slag placed on a 0 mm test piece, the slag placement surface is cut in the thickness direction as shown in FIG. 3 to reduce the thickness of the eroded layer and the slag permeated layer. It was evaluated by measuring.
【００３８】 耐衝撃性については、衝撃試験器を用い
て、縦１４０ｍｍ×横３０ｍｍ×厚さ６ｍｍのテストピ
ースに対してビレット材通過時の衝撃の１０倍の衝撃を
加え、テストピースが破壊されるまでの回数を測定する
ことにより評価した。With regard to the impact resistance, a test piece having a length of 140 mm × width of 30 mm × thickness of 6 mm was applied to a test piece having a length of 140 mm × width 30 mm × thickness 6 mm by using an impact tester to break the test piece. The evaluation was carried out by measuring the number of times until completion.
【００３９】（４）評価結果 初期加熱効率 セラミックチューブの比熱と、ビレット材−炉心管接触
部Ａ点が運転温度に達するまでの時間ｔ1（秒）との相
関について検証した。その結果を表２に示す。(4) Evaluation Results Initial Heating Efficiency The correlation between the specific heat of the ceramic tube and the time t 1 (second) until the billet material-core tube contact point A reaches the operating temperature was verified. Table 2 shows the results.
【００４０】[0040]
【表２】 [Table 2]
【００４１】 表２に示すように、比熱が本発明の範囲
外である比較例３〜比較例５はｔ1が４２０秒以上かか
ったのに対し、比熱が２ｋＪ／ｋｇ・Ｋ以下である、実
施例１〜実施例８についてはｔ1が３６０秒以下に短縮
され、初期加熱を早めることができた。即ち、加熱初期
に発生する不良の防止、エネルギーロスの減少を期待で
きる。As shown in Table 2, in Comparative Examples 3 to 5 in which the specific heat is out of the range of the present invention, t 1 took 420 seconds or more, while the specific heat was 2 kJ / kg · K or less. t 1 is reduced to below 360 seconds for example 1 to example 8, it was possible to accelerate the initial heating. In other words, it is possible to expect prevention of defects occurring at the beginning of heating and reduction of energy loss.
【００４２】 次に、セラミックチューブの熱伝導率
と、ビレット材−炉心管接触部Ａ点が運転温度に達した
後、前記Ａ点、上部管体と下部管体との接触部Ｂ点、上
部管体最上部Ｃ点の温度差Δｔが５℃以内となるまでの
時間ｔ2（秒）との相関について検証した。その結果を
表２に示す。Next, after the thermal conductivity of the ceramic tube and the contact point A between the billet material and the furnace tube reach the operating temperature, the point A, the contact point B between the upper tube and the lower tube, and the upper portion The correlation with the time t 2 (second) until the temperature difference Δt at the uppermost point C of the tube becomes within 5 ° C. was verified. Table 2 shows the results.
【００４３】 表２に示すように、熱伝導率が本発明の
範囲外である比較例４〜比較例５はｔ2が７０秒以上か
かったのに対し、熱伝導率が５０Ｗ／ｍ・Ｋ以上であ
る、実施例１〜実施例８についてはｔ2が６５秒以下に
短縮された。即ち、ビレット材等の被加熱体と非接触の
部分の加熱速度、及び加熱初期の炉心管からの熱放射率
を高めることが期待できる。As shown in Table 2, in Comparative Examples 4 and 5 in which the thermal conductivity was out of the range of the present invention, t 2 took 70 seconds or more, whereas the thermal conductivity was 50 W / m · K. or in which, t 2 is reduced to less than 65 seconds for examples 1 to 8. That is, it can be expected that the heating rate of the portion not in contact with the object to be heated, such as the billet material, and the heat emissivity from the furnace tube in the initial stage of heating can be increased.
【００４４】耐食性 セラミックチューブの見掛け気孔率と、耐食性との相関
について検証した。その結果を表２に示す。Corrosion Resistance The correlation between the apparent porosity of the ceramic tube and the corrosion resistance was examined. Table 2 shows the results.
【００４５】 表２に示すように、見掛け気孔率が本発
明の範囲外である比較例１，比較例２，比較例５はスラ
グによる侵食が認められ、侵食層も含めるとテストピー
ス厚みの１．８ｍｍ以上までスラグが浸透した。As shown in Table 2, in Comparative Examples 1, 2 and 5 in which the apparent porosity was out of the range of the present invention, erosion by slag was observed. The slag penetrated to 0.8 mm or more.
【００４６】 一方、見掛け気孔率が２％以下である、
実施例１〜実施例８についてはスラグによる侵食は殆ど
認められず、スラグの浸透も最大でも０．５ｍｍに止ま
り、高い耐食性が確認された。特に見掛け気孔率が０％
のＳｉ−ＳｉＣについては、極めて高い耐食性が確認さ
れた。On the other hand, the apparent porosity is 2% or less,
In Examples 1 to 8, almost no erosion by slag was observed, and permeation of slag was limited to 0.5 mm at the maximum, and high corrosion resistance was confirmed. Especially apparent porosity is 0%
As for Si-SiC, extremely high corrosion resistance was confirmed.
【００４７】耐衝撃性 セラミックチューブのヤング率と、耐衝撃性との相関に
ついて検証した。その結果を表４に示す。Impact Resistance The correlation between the Young's modulus of the ceramic tube and the impact resistance was verified. Table 4 shows the results.
【００４８】 表２に示すように、ヤング率が本発明の
範囲外である比較例１，比較例２，比較例４，比較例５
は衝撃を加える回数が１００回未満でもテストピースが
破損したのに対し、ヤング率が１５０ＧＮ／ｍ2以上で
ある、実施例１〜実施例８については３５０回以上衝撃
を加えてもテストピースは破壊されず、高い耐衝撃性が
確認された。即ち、ビレット材が炉心管内を通過する際
に強い衝撃が加わっても破損することがない炉心管を構
成することが期待できる。As shown in Table 2, Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5 having Young's modulus outside the range of the present invention.
Shows that the test piece was broken even when the number of times of impact was less than 100, whereas the Young's modulus was 150 GN / m 2 or more. It was not broken and high impact resistance was confirmed. That is, it can be expected that a core tube that is not damaged even when a strong impact is applied when the billet material passes through the core tube.
【００４９】[0049]
【発明の効果】 以上説明した通り、本発明のセラミッ
クチューブは、炉心管材料として充分な熱特性を有し、
耐食性、耐衝撃性も高いため、誘導加熱炉の炉心管とし
て好適に用いることができる。また、本発明のセラミッ
クチューブを炉心管として用いた誘導加熱炉は、加熱初
期に不良が発生し難く、エネルギーのロスも少なくする
ことができる。As described above, the ceramic tube of the present invention has sufficient thermal properties as a furnace tube material,
Since it has high corrosion resistance and impact resistance, it can be suitably used as a furnace tube of an induction heating furnace. In addition, in the induction heating furnace using the ceramic tube of the present invention as a furnace tube, defects are unlikely to occur in the early stage of heating, and energy loss can be reduced.
【図１】 誘導加熱炉の一の実施形態を示す縦断面図で
ある。FIG. 1 is a longitudinal sectional view showing one embodiment of an induction heating furnace.
【図２】 炉心管の一の実施形態を示す横断面図であ
る。FIG. 2 is a cross-sectional view showing one embodiment of a furnace tube.
【図３】 耐食性試験の方法を示す概略説明図であっ
て、（ａ）は斜視図、（ｂ）は縦断面図である。3A and 3B are schematic explanatory views showing a method of a corrosion resistance test, wherein FIG. 3A is a perspective view and FIG. 3B is a longitudinal sectional view.
１０…加熱ブロック、１１…炉心管、１１ａ…外部管
体、１１ｂ…内部管体、１１ｃ…フランジ部、１２…断
熱材、１３…コイル導管、１４…外殻、２０…ビレット
材、３０…テストピース、３１…スラグ、３２…侵食
層、３３…浸透層。DESCRIPTION OF SYMBOLS 10 ... Heating block, 11 ... Furnace tube, 11a ... Outer tube, 11b ... Inner tube, 11c ... Flange part, 12 ... Heat insulation material, 13 ... Coil conduit, 14 ... Outer shell, 20 ... Billet material, 30 ... Test Peace, 31 slag, 32 eroded layer, 33 permeable layer.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡元 優 愛知県名古屋市瑞穂区須田町２番56号 日 本碍子株式会社内 (72)発明者 二本松 浩明 岐阜県可児郡御嵩町美佐野3040番地 エヌ ジーケイ・アドレック株式会社内 (72)発明者 黒松 節夫 兵庫県姫路市勝原区山戸166番地２ 株式 会社黒松電機製作所内 Ｆターム(参考） 4E087 AA03 AA10 BA14 CA11 CA31 CB01 FB05 FB06 FB08 GB01 4G001 BA09 BA22 BA32 BA60 BA62 BB09 BB22 BB32 BB62 BC13 BC25 BC33 BC46 BC47 BD03 BD13 BD37 BE31 BE33 4K063 AA08 AA12 AA19 BA02 BA03 FA32 FA36 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yu Okamoto 2-56, Suda-cho, Mizuho-ku, Nagoya-shi, Aichi Japan Inside Nihon Insulators Co., Ltd. (72) Inventor Hiroaki Nihonmatsu 3040 Misano, Mitake-cho, Kani-gun, Gifu N (72) Inventor Setsuo Kuromatsu 166-2 Yamato, Katsuhara-ku, Himeji-shi, Hyogo F-term in Kuromatsu Electric Works (reference) 4E087 AA03 AA10 BA14 CA11 CA31 CB01 FB05 FB06 FB08 GB01 4G001 BA09 BA22 BA32 BA60 BA62 BB09 BB22 BB32 BB62 BC13 BC25 BC33 BC46 BC47 BD03 BD13 BD37 BE31 BE33 4K063 AA08 AA12 AA19 BA02 BA03 FA32 FA36
Claims (3)
ラミックチューブであって、 比熱が２ｋＪ／ｋｇ・Ｋ以下、熱伝導率が５０Ｗ／ｍ・
Ｋ以上、見掛け気孔率が２％以下、ヤング率が１５０Ｇ
Ｎ／ｍ2以上であるセラミックからなることを特徴とす
るセラミックチューブ。1. A ceramic tube for constituting a core tube of an induction heating furnace, having a specific heat of 2 kJ / kg · K or less and a thermal conductivity of 50 W / m ·
K or more, apparent porosity is 2% or less, Young's modulus is 150G
A ceramic tube comprising N / m 2 or more ceramic.
−ＳｉＣからなる請求項１に記載のセラミックチュー
ブ。2. Si having a metal Si content of 2 to 35% by weight
The ceramic tube according to claim 1, comprising -SiC.
ーブにより炉心管を構成したことを特徴とする誘導加熱
炉。3. An induction heating furnace, wherein a furnace tube is constituted by the ceramic tube according to claim 1 or 2.
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|---|---|---|---|
| JP12687099A JP3943282B2 (en) | 1999-05-07 | 1999-05-07 | Ceramic tube and induction heating furnace using the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12687099A JP3943282B2 (en) | 1999-05-07 | 1999-05-07 | Ceramic tube and induction heating furnace using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000319721A true JP2000319721A (en) | 2000-11-21 |
| JP3943282B2 JP3943282B2 (en) | 2007-07-11 |
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ID=14945887
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| Country | Link |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002080622A1 (en) * | 2001-03-30 | 2002-10-10 | Jfe Steel Corporation | Heat insulating board of induction heating apparatus |
| JP2008094661A (en) * | 2006-10-12 | 2008-04-24 | Ngk Insulators Ltd | Structural member for ceramic furnace |
| WO2012014835A1 (en) * | 2010-07-26 | 2012-02-02 | 日本碍子株式会社 | Rack for firing |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102527909B (en) * | 2012-01-16 | 2014-04-30 | 彭亦楚 | Continuous forging furnace |
-
1999
- 1999-05-07 JP JP12687099A patent/JP3943282B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002080622A1 (en) * | 2001-03-30 | 2002-10-10 | Jfe Steel Corporation | Heat insulating board of induction heating apparatus |
| CN1328931C (en) * | 2001-03-30 | 2007-07-25 | 杰富意钢铁株式会社 | Heat insulating board of induction heating apparatus |
| JP2008094661A (en) * | 2006-10-12 | 2008-04-24 | Ngk Insulators Ltd | Structural member for ceramic furnace |
| WO2012014835A1 (en) * | 2010-07-26 | 2012-02-02 | 日本碍子株式会社 | Rack for firing |
| JPWO2012014835A1 (en) * | 2010-07-26 | 2013-09-12 | 日本碍子株式会社 | Rack for baking |
| JP5722897B2 (en) * | 2010-07-26 | 2015-05-27 | 日本碍子株式会社 | Rack for baking |
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| Publication number | Publication date |
|---|---|
| JP3943282B2 (en) | 2007-07-11 |
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