JP4330111B2 - Heat treatment method and heat treatment furnace - Google Patents

Heat treatment method and heat treatment furnace Download PDF

Info

Publication number
JP4330111B2
JP4330111B2 JP2002348639A JP2002348639A JP4330111B2 JP 4330111 B2 JP4330111 B2 JP 4330111B2 JP 2002348639 A JP2002348639 A JP 2002348639A JP 2002348639 A JP2002348639 A JP 2002348639A JP 4330111 B2 JP4330111 B2 JP 4330111B2
Authority
JP
Japan
Prior art keywords
chamber
heat treatment
furnace
hearth roller
hearth
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.)
Expired - Fee Related
Application number
JP2002348639A
Other languages
Japanese (ja)
Other versions
JP2004183013A (en
Inventor
元和 村上
広良 鈴木
義幸 丹野
正史 山口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dowa Holdings Co Ltd
Original Assignee
Dowa Holdings Co Ltd
Dowa Mining Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Dowa Holdings Co Ltd, Dowa Mining Co Ltd filed Critical Dowa Holdings Co Ltd
Priority to JP2002348639A priority Critical patent/JP4330111B2/en
Priority to PCT/JP2003/015120 priority patent/WO2004050922A1/en
Priority to EP03812311A priority patent/EP1589120B1/en
Publication of JP2004183013A publication Critical patent/JP2004183013A/en
Application granted granted Critical
Publication of JP4330111B2 publication Critical patent/JP4330111B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0062Heat-treating apparatus with a cooling or quenching zone
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0006Details, accessories not peculiar to any of the following furnaces
    • C21D9/0018Details, accessories not peculiar to any of the following furnaces for charging, discharging or manipulation of charge
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0056Furnaces through which the charge is moved in a horizontal straight path
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27BFURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/02Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces
    • F27B9/028Multi-chamber type furnaces
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27BFURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/04Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity adapted for treating the charge in vacuum or special atmosphere
    • F27B9/045Furnaces with controlled atmosphere
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27BFURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30Details, accessories, or equipment peculiar to furnaces of these types
    • F27B9/40Arrangements of controlling or monitoring devices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00Casings; Linings; Walls; Roofs
    • F27D1/0003Linings or walls
    • F27D1/0006Linings or walls formed from bricks or layers with a particular composition or specific characteristics
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D19/00Arrangements of controlling devices

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Tunnel Furnaces (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)

Description

【0001】
【発明の属する技術分野】
本発明は、金属の熱処理方法及び熱処理炉に関し、詳しくは、ローラハースタイプの熱処理炉及びその熱処理方法に関する。
【0002】
【従来の技術】
従来、炉内レールタイプ熱処理炉として、図5に示す構成の炉が提供されている。同図において、10は、装入テーブル、11は、熱処理室、12は、油槽、13は、出口コンベア、Wはワークである(例えば、特許文献1参照。)。
【0003】
前記の炉内レールタイプのバッチ炉は、例えば、浸炭処理の場合、同じ室で浸炭(930〜1050℃)及び降温均熱(830〜850℃)を繰り返すため、昇温、降温均熱に時間がかかり、生産効率及び熱効率が悪いという問題がある。また、炉内レール受けがレンガであり、脆く、蓄熱量が大きいため、シーズニング時間が大きいという問題も残されている。
【0004】
その他、ハースローラタイプのバッチ炉として、図6に示す構成の炉が提供されている。なお、同図において、前記図4と同一部分には同一符号を付してある。図中、14は、ハースローラである(例えば、特許文献2参照)。
【0005】
前記ハースローラタイプのバッチ炉も前記炉内レールタイプのバッチ炉と同様に、例えば、浸炭処理の場合、同じ室で浸炭(930〜1050℃)及び降温均熱(830〜850℃)を繰り返すため、昇温、降温均熱に時間がかかり、生産効率及び熱効率が悪いという問題がある。また、高温の熱処理室における前記ハースローラ14の変形を防止するため、ワークWが供給された状態で前記ハースローラ14を常時正回転及び逆回転させるスペースが必要であり、さらに、ハースローラ14の両端が炉壁を貫通しているため、熱放射が大きいという問題が残されている(例えば、特許文献2参照)。
【0006】
【特許文献1】
特許第3103905号公報
【0007】
【特許文献2】
特開昭63−33552号公報
【0008】
【発明が解決しようとする課題】
本発明は、前記構成の炉内レールタイプ及びハースローラタイプバッチ炉の問題を解決し、生産効率及び熱効率を高めた経済的な熱処理方法及び該熱処理方法を実施するコンパクトで経済的な熱処理炉を提供することを目的とする。
【0009】
【課題を解決するための手段】
請求項1に示す熱処理方法は、直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室にそれぞれ独立駆動のハースローラが設けられた熱処理炉において、ワークの加熱処理時には前記熱処理室のハースローラの正回転とその停止とを繰り返すインチングを行うことを特徴とする熱処理方法である。
【0010】
上記請求項1の発明によれば、炉本体内部が仕切扉により予熱窒、熱処理室及び均熱室に区画されているため、各種熱処理における雰囲気及び温度制御を正確に行うことができる。
【0011】
また、従来のローラハース炉においては、高温加熱によるハースローラの変形を防止するため、熱処理室において、前記ハースローラを正回転及び逆回転させていたが、本発明では、前記熱処理室においては前記ハースローラを逆回転させない。すなわち、インチングのみを行うことを特徴とする。
【0012】
上記の結果、ワークを往復動させるためのスペースが不要になり、前記熱処理室及び炉本体全体のコンパクト化が図られる。同時に、攪拌ファンによる雰囲気ガスの攪拌効果、すなわち、雰囲気ガスの流速分布がより均一になり、熱処理室内の均熱の向上が確認された。例えば、前記従来のハースローラを正回転及び逆回転させる炉では±7.5℃であったのに対して、本発明に係るコンパクト化された炉では±6.0℃以内になったことが確認され、前記従来の炉に比べて処理品の品質向上が可能となった。
【0013】
さらに、前記熱処理室のコンパクト化は、該熱処理室が高温であることから、特に効果が大きい。すなわち、加熱に要するヒーターやバーナー、その電力やガスの消費量及びその経費削減、さらには断熱材等の大幅な経費削減になる。
【0014】
請求項2に示す熱処理方法は、直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室にそれぞれ独立駆動のハースローラが設けられた熱処理炉において、ワークの予熱時及び均熱時には、前記予熱室及び均熱室のハースローラを正回転及び逆回転させてワークを揺動させ、ワークの加熱処理時には前記熱処理室のハースローラの正回転とその停止とを繰り返すインチングを行うことを特徴とする熱処理方法である。
【0015】
上記請求項2の本発明によれば、請求項1による前記作用効果に加えて、均一に予熱したワークを前記熱処理室に供給でき、さらに熱処理完了ワークの正確な均熱化が可能となる利点がある。
【0016】
請求項3に示す熱処理炉は、直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室に独立駆動のハースローラが設けられてなり、前記予熱室及び均熱室のハースローラが正回転及び逆回転自在に、前記加熱室のハースローラが正回転のみに構成され、前記熱処理室の前記ハースローラが超耐熱鋼に微量のタングステン、コバルト、チタンを添加してクリープ特性を高めた素材であることを特徴とする。したがって、前記熱処理室においては、正回転あるいはインチングのみが行われる。
【0017】
この請求項3の発明によれば、前記請求項1及び請求項2に記載の熱処理方法を容易に実施することができ、同時に熱処理室においてワークを往復動させることがないため、前記熱処理室及び炉本体全体のコンパクト化が図られる。この熱処理室のコンパクト化は、前記請求項1に関連して述べたごとく、大幅な経費削減を可能にする。
【0018】
また、請求項3に係る本発明によれば、前記熱処理室の前記ハースローラが前記特徴を有するので、前記熱処理室内において、従来のように、ハースローラを正回転及び逆回転させてその変形を防止する必要がなく、ハースローラを停止させたままワークの熱処理を行うことができ、したがって、ワークを往復動させるためのスペースが不要であり、炉本体全体のコンパクト化が図られる。また、ハースローラの径を小さくできるため、炉壁を貫通している両端からの放熱量を減少させることができる。
【0019】
請求項に示す熱処理炉の実施の一形態は、前記炉本体の炉壁が炉内からレンガ層、シリカ層、酸化チタン及び無機ファイバーの圧縮成形体で構成されてなることを特徴とする。この請求項の実施の一形態によれば、炉壁の断熱効果の向上に伴い、炉表面からの熱放散が低減させられ、加熱エネルギーの節減による経済的効果が得られる。また、炉壁厚の縮小が可能であり、同時に、ハースローラの短縮及び該短縮に伴うハースローラの変形防止効果の向上を図ることができる。なお、請求項3,4において、前記熱処理室の具体例としては、浸炭室、軟窒化室、調質室を挙げることができる(請求項5)。
【0020】
【発明の実施の形態】
以下に、本発明の実施の一形態を図面に基づいて説明する。図1は、本発明に係る熱処理炉の概略側面図及び浸炭処理実施例、図2は、本発明に係る熱処理炉の概略側面図及び軟窒化処理実施例、図3は、本発明に係る熱処理炉の概略側面図及び調質処理実施例、図4は、本発明に係る熱処理炉の炉壁断面図及び断熱温度曲線図、図5は、従来のレールタイプバッチ炉の概略側面図、図6は、従来のハースローラタイプのバッチ炉の概略側面図である。
【0021】
本発明に係る熱処理炉1は、図1乃至図3に示すように、直線状の炉本体の内部に、仕切扉1及び2を介して、予熱室3、熱処理室4及び均熱室5が設けられる。図中、10は、装入テーブル、12は、油槽、13は、出口コンベアである。さらに、好ましい例として、図面実施例では、前記予熱室3:熱処理室4及び均熱室5:熱処理室4が、それぞれ1:3の大きさに構成され、全長を従来炉とほぼ同様にして、約3倍の生産量を可能にしている。
【0022】
本発明では、前記予熱室3、熱処理室4及び均熱室5に、それぞれ独立駆動のハースローラ6、7及び8が設けられる。さらに、前記予熱室3及び均熱室5内のハースローラ6及び8が正回転及び逆回転自在に構成され、前記熱処理室4内のハースローラ7が正回転あるいはインチングのみ可能に構成される。
【0023】
なお、前記ハースローラ6、7及び8は、超耐熱鋼に微量のタングステン、コバルト、チタンが添加されてクリープ特性が高められているため、従来のごとく、前記熱処理室4内において、正回転及び逆回転を繰り返してその変形を防止する必要がない。したがって、前記熱処理室4内においてワークWを往復動させるためのスペースが不要であり、熱処理室及び炉本体全体のコンパクト化が図られる。また、ハースローラの径を、例えば、従来の104mmから90mmに小さくできるため、炉壁を貫通している両端からの放熱量を減少させることができる。
【0024】
前記ハースローラの変形、具体的には、曲がりは、該ハースローラの強度とともに、ワークWの温度と炉内温度との温度差が大きく影響する。その点、前記ワークWの温度と炉内温度との温度差が大きいのは予熱室3であり、したがって、予熱室3において、ハースローラ6を正回転及び逆回転させ、前記温度差を小さくした後、前記熱処理室4に供給することにより、該熱処理室4におけるハースローラ7の変形を最小限に抑えることができる。
【0025】
なお、浸炭炉における熱処理室において、従来品及び本願実施の一形態のハースローラを試みたところ、従来品の場合、受入れ時、2mm以下の曲がりであったものが、3ケ月の使用後には、5mm以上の曲がりとなり、交換の必要が発生したのに対し、前記本願実施の一形態におけるハースローラは、受入れ時、0.3mmであったものが、8ケ月の使用後においても、1mm以下の状態であり、交換の必要性はなかった。
【0026】
なお、前記数値は、ハースローラ両端の鍔部からそれぞれ内側に75mmの地点と中央地点間をダイヤルゲ―ジによって測定したものであり、前記従来品のハースローラは、正回転及び逆回転を繰り返した場合であり、前記本願実施の一形態におけるハースローラは、インチング(停止及び正回転)のみを行った場合である。
【0027】
図4には、本発明に係る熱処理炉の炉壁構造及び断熱温度曲線図が示されている。すなわち、炉壁が炉内から115mmのレンガ層15、85mmのシリカ層16、50mmのチタン及び無機ファイバーの圧縮成形体層17で構成されている。また、断熱温度曲線を見ると、炉内温度950℃に維持した炉本体の表面温度は50.2℃(大気温度:20℃)であり、炉壁厚の大幅な削減とともに改正省エネルギー法の遵守が可能となった。
【0028】
前記本発明の熱処理炉は、金属の各種熱処理に使用される。図1は浸炭処理の一実施例である。すなわち、装入テーブル10に供給されたワークWが、図示しない装入扉を介して予熱室3に供給され、該予熱室3内のハースローラ6が正回転及び逆回転させられて均一予熱が行われる。
【0029】
その後、前記予熱室3と前記熱処理室4間の仕切扉1が開かれ、前記ハースローラ6及び7が駆動させられ、ワークWが前記熱処理室4へ搬送され、例えば、所定雰囲気のカーボンポテンシャル1.0%及び所定温度の940℃にて、所定時間の540分間の浸炭処理が行われる。
【0030】
図1乃至図3に示す熱処理炉では、熱処理室(浸炭室)4内に設けられたハースローラ7を正回転あるいはインチングさせてワークWを前記熱処理室4内の所定位置に順次移動させ、ハースローラ7を逆回転させることなく浸炭処理が行われる。
【0031】
具体的には、前記した浸炭処理条件の場合には、前記熱処理室4内へ搬送及び収容可能な三ブロックのワークWが、前記熱処理室4内に、それぞれ540分間滞在させられて浸炭処理が行われるように、前記熱処理4内のハースローラ7が正回転あるいはインチング及び停止させられて浸炭処理が行われる。同時に浸炭処理を完了したワークWが均熱室5へ搬送され、さらに予熱室3から浸炭処理するつぎのワークWの搬入が行われる。
【0032】
前記熱処理室4において浸炭処理が完了したワークWは、前記熱処理室4と均熱室5間の仕切扉2が開かれ、前記ハースローラ7及び8が駆動させられて前記均熱室5へ搬送され、該均熱室5内のハースローラ8が正回転及び逆回転させられて、所定の均熱温度、例えば、850℃に降温、均熱保持される。
【0033】
その後、図示しない均熱室5と油槽12間の開閉扉が開かれて、均熱ワークWの焼入れが行われ、該焼入れ完了とともに、図示しない出口扉が開かれて、ワークWが出口コンベア13へ搬出される。
【0034】
前記のごとく、図1乃至図3に示す熱処理炉では、前記予熱室3へのワークWの装入、該予熱室3から前記熱処理室4へのワークWの搬送、該熱処理室4から前記均熱室5へのワークWの搬送、さらには該均熱室5から油槽12へのワークWの搬送、該油槽12から前記出口コンベア13へのワークWの搬出が効率よく、連続的に行われ、生産効率が高められる。
【0035】
図2は、軟窒化処理の一実施例である。すなわち、装入テーブル10に供給されたワークWが、図示しない装入扉を介して予熱室3に供給され、該予熱室3内のハースローラ6が正回転及び逆回転させられて均一予熱が行われる。その後、前記予熱室3と前記熱処理室4間の仕切扉1が開かれ、前記ハースローラ6及び7が駆動させられ、ワークWが前記熱処理室(軟窒化室)4へ搬送され、所定雰囲気のRXガス及びアンモニアガス中で、例えば、所定温度の550℃、所定時間の120分間の軟窒化処理が行われる。
【0036】
前記熱処理室4において所定時間の軟窒化処理が完了すると、前記熱処理室4と、前記均熱室5間の仕切扉2が開かれ、前記ハースローラ7及び8が駆動させられ、ワークWが前記均熱室5に搬送され、均熱工程を経ることなく、図示しない均熱室5と油槽12間の開閉扉が開かれてワークWの焼入れが行われ、該焼入れ完了とともに、図示しない出口扉が開かれて、ワークWが出口コンベア13へ搬送される。
【0037】
図3は、調質処理の一実施例である。すなわち、装入テーブル10に供給されたワークWが、図示しない装入扉を介して予熱室3に供給され、該予熱室3内のハースローラ6が正回転及び逆回転させられて均一予熱が行われる。その後、前記予熱室3と前記熱処理室4間の仕切扉1が開かれ、前記ハースローラ6及び7が駆動させられ、ワークWが前記熱処理室(調質室)4へ搬送され、所定雰囲気のカーボンポテンシャル0.3〜0.5%中で、例えば、所定温度の880℃、所定時間の30分の調質処理が行われる。
【0038】
その後の工程は、前記軟窒化処理の場合と同様であり、均熱工程を経ることなく、焼入れが行われる。
【0039】
【発明の効果】
前記本発明によれば、生産効率及び熱効率を高めた熱処理方法及び該熱処理方法を実施するコンパクトで経済的な熱処理炉を提供することができる。
【図面の簡単な説明】
【図1】本発明に係る熱処理炉の概略側面図及び浸炭処理実施例を示す図である。
【図2】本発明に係る熱処理炉の概略側面図及び軟窒化処理実施例を示す図である。
【図3】本発明に係る熱処理炉の概略側面図及び調質処理実施例を示す図である。
【図4】本発明に係る熱処理炉の炉壁断面図及び断熱温度曲線図である。
【図5】従来のレールタイプバッチ炉の概略側面図である。
【図6】従来のハースローラタイプバッチ炉の概略側面図である。
【符号の説明】
1 仕切扉
2 仕切扉
3 予熱室
4 熱処理室
5 均熱室
6 ハースローラ
7 ハースローラ
8 ハースローラ
15 レンガ層
16 シリカ層
17 酸化チタン及び無機ファイバーの圧縮成形体層
[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal heat treatment method and a heat treatment furnace, and more particularly to a roller hearth type heat treatment furnace and a heat treatment method thereof.
[0002]
[Prior art]
Conventionally, a furnace configured as shown in FIG. 5 is provided as an in-furnace rail type heat treatment furnace. In the same figure, 10 is a charging table, 11 is a heat treatment chamber, 12 is an oil tank, 13 is an outlet conveyor, and W is a work (for example, refer to Patent Document 1).
[0003]
For example, in the case of a carburizing process, the above-described in-furnace rail type batch furnace repeats carburizing (930 to 1050 ° C.) and temperature-decreasing soaking (830 to 850 ° C.) in the same chamber. There is a problem that production efficiency and thermal efficiency are poor. Moreover, since the in-furnace rail receiver is a brick, it is brittle, and the amount of heat stored is large, there is still a problem that the seasoning time is long.
[0004]
In addition, a furnace having the configuration shown in FIG. 6 is provided as a hearth roller type batch furnace. In this figure, the same parts as those in FIG. In the figure, reference numeral 14 denotes a hearth roller (see, for example, Patent Document 2).
[0005]
For example, in the case of carburizing treatment, the hearth roller type batch furnace repeats carburizing (930 to 1050 ° C.) and temperature-decreasing soaking (830 to 850 ° C.) in the same chamber. There is a problem that it takes time to raise and lower the temperature, and production efficiency and thermal efficiency are poor. Further, in order to prevent deformation of the hearth roller 14 in a high-temperature heat treatment chamber, a space for always rotating the hearth roller 14 forward and backward in a state where the workpiece W is supplied is required, and both ends of the hearth roller 14 are furnaces. Since it penetrates the wall, there remains a problem that heat radiation is large (see, for example, Patent Document 2).
[0006]
[Patent Document 1]
Japanese Patent No. 3103905 gazette
[Patent Document 2]
JP-A-63-33552
[Problems to be solved by the invention]
The present invention solves the problems of the in-furnace rail type and the hearth roller type batch furnace having the above-described configuration, and provides an economical heat treatment method that increases production efficiency and thermal efficiency, and a compact and economical heat treatment furnace that performs the heat treatment method. The purpose is to provide.
[0009]
[Means for Solving the Problems]
The heat treatment method according to claim 1 is a heat treatment furnace in which a preheating chamber, a heat treatment chamber, and a soaking chamber are provided in a linear furnace main body via a partition door, and an independently driven hearth roller is provided in each chamber. In the heat treatment method, the inching is repeatedly performed between the forward rotation and the stop of the hearth roller in the heat treatment chamber during the heat treatment of the workpiece.
[0010]
According to the first aspect of the present invention, since the interior of the furnace body is partitioned into the preheating nitrogen, the heat treatment chamber and the soaking chamber by the partition door, the atmosphere and temperature control in various heat treatments can be accurately performed.
[0011]
Further, in the conventional roller hearth furnace, in order to prevent the deformation of the hearth roller due to high temperature heating, the hearth roller is rotated forward and backward in the heat treatment chamber, but in the present invention, the hearth roller is reversed in the heat treatment chamber. Do not rotate. That, and performs only Lee Nchingu.
[0012]
As a result, there is no need for a space for reciprocating the workpiece, and the heat treatment chamber and the entire furnace body can be made compact. At the same time, the effect of stirring the atmosphere gas by the stirring fan, that is, the flow velocity distribution of the atmosphere gas became more uniform, and the improvement of soaking in the heat treatment chamber was confirmed. For example, it was confirmed that the temperature of the conventional hearth roller was ± 7.5 ° C. in the forward and reverse rotation furnaces, whereas the compacted furnace according to the present invention was within ± 6.0 ° C. Thus, the quality of the processed product can be improved as compared with the conventional furnace.
[0013]
Further, the downsizing of the heat treatment chamber is particularly effective because the heat treatment chamber is hot. That is, the heater and burner required for heating, the consumption of electric power and gas and the cost thereof, and the cost of the heat insulating material are greatly reduced.
[0014]
The heat treatment method according to claim 2 is a heat treatment furnace in which a preheating chamber, a heat treatment chamber, and a soaking chamber are provided in a linear furnace main body through a partition door, and an independently driven hearth roller is provided in each chamber. In the preheating and soaking of the workpiece, the preheating chamber and the soaking chamber in the soaking chamber are rotated in the forward and reverse directions to swing the workpiece, and in the heat treatment of the workpiece , the forward rotation of the hearth roller in the heat treatment chamber and its stop Is a heat treatment method characterized by performing inching repeatedly .
[0015]
According to the second aspect of the present invention, in addition to the function and effect of the first aspect, it is possible to supply a uniformly preheated workpiece to the heat treatment chamber, and further, it is possible to accurately equalize the heat treated workpiece. There is.
[0016]
The heat treatment furnace shown in claim 3 is provided with a preheating chamber, a heat treatment chamber, and a soaking chamber through a partition door inside a linear furnace body, and each chamber is provided with independently driven hearth rollers, The hearth roller in the preheating chamber and soaking chamber can be rotated forward and backward freely, the hearth roller in the heating chamber is configured only for forward rotation, and the hearth roller in the heat treatment chamber adds a small amount of tungsten, cobalt, and titanium to super heat resistant steel. It is characterized by being a material with improved creep characteristics . Therefore, only forward rotation or inching is performed in the heat treatment chamber.
[0017]
According to the third aspect of the present invention, the heat treatment method according to the first and second aspects can be easily performed, and at the same time, the workpiece is not reciprocated in the heat treatment chamber. The whole furnace body can be made compact. As described in connection with claim 1, the downsizing of the heat treatment chamber enables a significant cost reduction.
[0018]
Further, according to the present invention of claim 3, since the hearth roller in the heat treatment chamber has the characteristics , the hearth roller is rotated forward and backward in the heat treatment chamber to prevent its deformation as in the prior art. There is no need, and the heat treatment of the workpiece can be performed while the hearth roller is stopped. Therefore, a space for reciprocating the workpiece is unnecessary, and the entire furnace body can be made compact. Moreover, since the diameter of the hearth roller can be reduced, the amount of heat released from both ends penetrating the furnace wall can be reduced.
[0019]
One form of embodiment of the heat treatment furnace shown in claim 4, characterized in that the furnace wall of said furnace body is formed of a furnace brick layer, silica layer, the compression molding of the titanium oxide and inorganic fibers . According to the embodiment of the fourth aspect, with the improvement of the heat insulating effect of the furnace wall, the heat dissipation from the furnace surface is reduced, and the economic effect due to the reduction of heating energy is obtained. In addition, the thickness of the furnace wall can be reduced, and at the same time, the hearth roller can be shortened and the deformation preventing effect of the hearth roller can be improved. In Claims 3 and 4, specific examples of the heat treatment chamber include a carburizing chamber, a soft nitriding chamber, and a tempering chamber (Claim 5).
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view of a heat treatment furnace according to the present invention and a carburizing treatment example, FIG. 2 is a schematic side view of the heat treatment furnace according to the present invention and a soft nitriding treatment example, and FIG. 3 is a heat treatment according to the present invention. FIG. 4 is a sectional view of a furnace wall and an adiabatic temperature curve of the heat treatment furnace according to the present invention, FIG. 5 is a schematic side view of a conventional rail type batch furnace, and FIG. These are the schematic side views of the conventional hearth roller type batch furnace.
[0021]
As shown in FIGS. 1 to 3, the heat treatment furnace 1 according to the present invention includes a preheating chamber 3, a heat treatment chamber 4, and a soaking chamber 5 inside a linear furnace body via partition doors 1 and 2. Provided. In the figure, 10 is a charging table, 12 is an oil tank, and 13 is an outlet conveyor. Furthermore, as a preferred example, in the drawing embodiment, the preheating chamber 3: heat treatment chamber 4 and the soaking chamber 5: heat treatment chamber 4 are each configured to have a size of 1: 3, and the overall length is substantially the same as that of a conventional furnace. , Enabling about three times the production volume.
[0022]
In the present invention, the preheating chamber 3, the heat treatment chamber 4, and the soaking chamber 5 are provided with independently driven hearth rollers 6, 7, and 8, respectively. Further, the hearth rollers 6 and 8 in the preheating chamber 3 and the soaking chamber 5 are configured to be freely rotatable in the forward and reverse directions, and the hearth roller 7 in the heat treatment chamber 4 is configured to be capable of rotating only forward or inching.
[0023]
The hearth rollers 6, 7 and 8 have a creep property enhanced by adding a small amount of tungsten, cobalt, and titanium to super heat resistant steel. There is no need to repeat the rotation to prevent its deformation. Therefore, a space for reciprocating the workpiece W in the heat treatment chamber 4 is not required, and the heat treatment chamber and the entire furnace body can be made compact. Moreover, since the diameter of the hearth roller can be reduced from, for example, the conventional 104 mm to 90 mm, the amount of heat released from both ends penetrating the furnace wall can be reduced.
[0024]
The deformation of the hearth roller, specifically, the bending, is greatly affected by the temperature difference between the temperature of the workpiece W and the furnace temperature, along with the strength of the hearth roller. In this respect, the temperature difference between the temperature of the workpiece W and the furnace temperature is large in the preheating chamber 3. Therefore, in the preheating chamber 3, the hearth roller 6 is rotated forward and backward to reduce the temperature difference. By supplying the heat treatment chamber 4 to the heat treatment chamber 4, the deformation of the hearth roller 7 in the heat treatment chamber 4 can be minimized.
[0025]
In addition, in the heat treatment chamber in the carburizing furnace, when the conventional product and the hearth roller of the embodiment of the present application were tried, the conventional product had a bending of 2 mm or less at the time of acceptance, but it was 5 mm after 3 months of use. The above-mentioned bend and the need for replacement occurred, whereas the hearth roller in one embodiment of the present application was 0.3 mm at the time of acceptance, but it is still in a state of 1 mm or less even after 8 months of use. There was no need for replacement.
[0026]
The above values are measured with a dial gauge between a point of 75 mm inward and a central point from the flanges at both ends of the hearth roller, and the conventional hearth roller repeats forward and reverse rotations. Yes, the hearth roller in the embodiment of the present application is a case where only inching (stop and forward rotation) is performed.
[0027]
FIG. 4 shows a furnace wall structure and adiabatic temperature curve diagram of the heat treatment furnace according to the present invention. That is, the furnace wall is composed of a 115 mm brick layer 15, an 85 mm silica layer 16, a 50 mm titanium and inorganic fiber compression molding layer 17 from the furnace. Also, looking at the adiabatic temperature curve, the furnace body surface temperature maintained at 950 ° C in the furnace was 50.2 ° C (atmospheric temperature: 20 ° C), and the furnace wall thickness was significantly reduced and the revised Energy Conservation Law was observed. Became possible.
[0028]
The heat treatment furnace of the present invention is used for various heat treatments of metals. FIG. 1 shows an embodiment of the carburizing process. That is, the workpiece W supplied to the charging table 10 is supplied to the preheating chamber 3 via a charging door (not shown), and the hearth roller 6 in the preheating chamber 3 is rotated forward and backward to perform uniform preheating. Is called.
[0029]
Thereafter, the partition door 1 between the preheating chamber 3 and the heat treatment chamber 4 is opened, the hearth rollers 6 and 7 are driven, and the workpiece W is transferred to the heat treatment chamber 4, for example, a carbon potential 1. A carburizing process for 540 minutes for a predetermined time is performed at 0% and a predetermined temperature of 940 ° C.
[0030]
In the heat treatment furnace shown in FIGS. 1 to 3, the heat treatment chamber (carburizing chamber) the Hasurora 7 provided in the 4 by the forward rotation or inching is sequentially moving the work W to a predetermined position of the heat treatment chamber 4, Hasurora The carburizing process is performed without rotating 7 reversely.
[0031]
Specifically, in the case of the above-described carburizing process conditions, three blocks of workpieces W that can be transported and accommodated in the heat treatment chamber 4 are allowed to stay in the heat treatment chamber 4 for 540 minutes, respectively. As is performed, the hearth roller 7 in the heat treatment 4 is rotated forward or inching and stopped to perform a carburizing process. At the same time, the workpiece W that has been carburized is transferred to the soaking chamber 5, and the next workpiece W to be carburized from the preheating chamber 3 is carried in.
[0032]
The workpiece W that has been carburized in the heat treatment chamber 4 is conveyed to the heat equalization chamber 5 by opening the partition door 2 between the heat treatment chamber 4 and the heat equalization chamber 5 and driving the hearth rollers 7 and 8. Then, the hearth roller 8 in the soaking chamber 5 is rotated forward and reverse, and the temperature is lowered to a predetermined soaking temperature, for example, 850 ° C. and kept soaked.
[0033]
Thereafter, an opening / closing door (not shown) between the soaking chamber 5 and the oil tank 12 is opened to quench the soaking work W. Upon completion of the quenching, the exit door (not shown) is opened and the work W is moved to the exit conveyor 13. It is carried out to.
[0034]
As described above, in the heat treatment furnace shown in FIGS. 1 to 3, the work W is charged into the preheating chamber 3, the work W is transferred from the preheating chamber 3 to the heat treatment chamber 4, and the equalization from the heat treatment chamber 4 is performed. The work W is transferred to the heat chamber 5, and further, the work W is transferred from the soaking chamber 5 to the oil tank 12, and the work W is transferred from the oil tank 12 to the outlet conveyor 13 efficiently and continuously. , Production efficiency is increased.
[0035]
FIG. 2 shows an example of the soft nitriding process. That is, the workpiece W supplied to the charging table 10 is supplied to the preheating chamber 3 via a charging door (not shown), and the hearth roller 6 in the preheating chamber 3 is rotated forward and backward to perform uniform preheating. Is called. After that, the partition door 1 between the preheating chamber 3 and the heat treatment chamber 4 is opened, the hearth rollers 6 and 7 are driven, and the workpiece W is transferred to the heat treatment chamber (soft nitriding chamber) 4 so as to have RX in a predetermined atmosphere. In the gas and ammonia gas, for example, a soft nitriding process is performed at a predetermined temperature of 550 ° C. for a predetermined time of 120 minutes.
[0036]
When the soft nitriding treatment for a predetermined time is completed in the heat treatment chamber 4, the partition door 2 between the heat treatment chamber 4 and the soaking chamber 5 is opened, the hearth rollers 7 and 8 are driven, and the work W is moved to the soaking. Without being subjected to a soaking process, the open / close door between the soaking chamber 5 and the oil tank 12 is opened and the workpiece W is quenched without being subjected to a soaking step. The workpiece W is opened and conveyed to the exit conveyor 13.
[0037]
FIG. 3 shows an example of the tempering process. That is, the workpiece W supplied to the charging table 10 is supplied to the preheating chamber 3 via a charging door (not shown), and the hearth roller 6 in the preheating chamber 3 is rotated forward and backward to perform uniform preheating. Is called. After that, the partition door 1 between the preheating chamber 3 and the heat treatment chamber 4 is opened, the hearth rollers 6 and 7 are driven, and the workpiece W is transferred to the heat treatment chamber (tempering chamber) 4, and carbon in a predetermined atmosphere. In a potential of 0.3 to 0.5%, for example, a tempering process is performed at a predetermined temperature of 880 ° C. for a predetermined time of 30 minutes.
[0038]
The subsequent steps are the same as in the soft nitriding process, and quenching is performed without going through a soaking step.
[0039]
【The invention's effect】
According to the present invention, it is possible to provide a heat treatment method with improved production efficiency and thermal efficiency, and a compact and economical heat treatment furnace for performing the heat treatment method.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a heat treatment furnace according to the present invention and a diagram showing an example of a carburizing process.
FIG. 2 is a schematic side view of a heat treatment furnace according to the present invention and a diagram showing an embodiment of a soft nitriding treatment.
FIG. 3 is a schematic side view of a heat treatment furnace according to the present invention and a diagram showing an example of a tempering treatment.
FIG. 4 is a cross-sectional view of a furnace wall and an adiabatic temperature curve of a heat treatment furnace according to the present invention.
FIG. 5 is a schematic side view of a conventional rail type batch furnace.
FIG. 6 is a schematic side view of a conventional hearth roller type batch furnace.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Partition door 2 Partition door 3 Preheating chamber 4 Heat treatment chamber 5 Soaking chamber 6 Hearth roller 7 Hearth roller 8 Hearth roller 15 Brick layer 16 Silica layer 17 Compression molding layer of titanium oxide and inorganic fiber

Claims (5)

直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室にそれぞれ独立駆動のハースローラが設けられた熱処理炉において、ワークの加熱処理時には前記熱処理室のハースローラの正回転とその停止とを繰り返すインチングを行うことを特徴とする熱処理方法。In a heat treatment furnace in which a preheating chamber, a heat treatment chamber and a soaking chamber are provided in a linear furnace main body via a partition door, and each chamber is provided with an independently driven hearth roller, the heat treatment is performed during the heat treatment of the workpiece. A heat treatment method characterized by performing inching which repeats forward rotation and stopping of a hearth roller in a chamber. 直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室にそれぞれ独立駆動のハースローラが設けられた熱処理炉において、ワークの予熱時及び均熱時には、前記予熱室及び均熱室のハースローラを正回転及び逆回転させてワークを揺動させ、ワークの加熱処理時には前記熱処理室のハースローラの正回転とその停止とを繰り返すインチングを行うことを特徴とする熱処理方法。In a heat treatment furnace in which a preheating chamber, a heat treatment chamber, and a soaking chamber are provided through a partition door inside the linear furnace body, and an independent drive hearth roller is provided in each chamber, the workpiece is preheated and soaked. Sometimes, the workpiece is rocked by rotating the hearth rollers in the preheating chamber and the soaking chamber in forward and backward directions, and inching is repeatedly performed between the forward rotation and stopping of the hearth roller in the heat treatment chamber during the heat treatment of the workpiece. A heat treatment method. 直線状の炉本体内部に、仕切扉を介して予熱室、熱処理室及び均熱室が設けられ、前記各室にそれぞれ独立駆動のハースローラが設けられてなり、前記予熱室及び均熱室のハースローラが正回転及び逆回転自在に構成され、前記熱処理室のハースローラが正回転のみに構成され、前記熱処理室の前記ハースローラが超耐熱鋼に微量のタングステン、コバルト、チタンを添加してクリープ特性を高めた素材であることを特徴とする熱処理炉。Inside the linear furnace body, a preheating chamber, a heat treatment chamber, and a soaking chamber are provided via a partition door, and an independently driven hearth roller is provided in each chamber, and the hearth roller of the preheating chamber and the soaking chamber is provided. Is configured to freely rotate in the forward and reverse directions, the hearth roller in the heat treatment chamber is configured only in the forward rotation, and the hearth roller in the heat treatment chamber adds a small amount of tungsten, cobalt, and titanium to super heat-resistant steel to enhance creep characteristics. A heat treatment furnace characterized by being made of a material . 前記炉本体の炉壁が炉内からレンガ層、シリカ層、酸化チタン及び無機ファイバーの圧縮成形体層で構成されてなることを特徴とする請求項3に記載の熱処理炉。The heat treatment furnace according to claim 3, wherein the furnace wall of the furnace body is formed of a compression molded body layer of a brick layer, a silica layer, titanium oxide, and inorganic fibers from the inside of the furnace. 前記熱処理室が、浸炭室、軟窒化室又は調質室であることを特徴とする請求項3又は4に記載の熱処理炉。The heat treatment furnace according to claim 3 or 4, wherein the heat treatment chamber is a carburizing chamber, a soft nitriding chamber, or a tempering chamber.
JP2002348639A 2002-11-29 2002-11-29 Heat treatment method and heat treatment furnace Expired - Fee Related JP4330111B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2002348639A JP4330111B2 (en) 2002-11-29 2002-11-29 Heat treatment method and heat treatment furnace
PCT/JP2003/015120 WO2004050922A1 (en) 2002-11-29 2003-11-27 Method and furnace for heat treatment
EP03812311A EP1589120B1 (en) 2002-11-29 2003-11-27 Method and furnace for heat treatment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2002348639A JP4330111B2 (en) 2002-11-29 2002-11-29 Heat treatment method and heat treatment furnace

Publications (2)

Publication Number Publication Date
JP2004183013A JP2004183013A (en) 2004-07-02
JP4330111B2 true JP4330111B2 (en) 2009-09-16

Family

ID=32462929

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2002348639A Expired - Fee Related JP4330111B2 (en) 2002-11-29 2002-11-29 Heat treatment method and heat treatment furnace

Country Status (3)

Country Link
EP (1) EP1589120B1 (en)
JP (1) JP4330111B2 (en)
WO (1) WO2004050922A1 (en)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4876279B2 (en) * 2004-09-13 2012-02-15 Dowaサーモテック株式会社 Heat treatment furnace
JP4982762B2 (en) * 2005-09-30 2012-07-25 Dowaサーモテック株式会社 Heat treatment furnace
JP4982763B2 (en) * 2005-09-30 2012-07-25 Dowaサーモテック株式会社 Continuous heat treatment furnace
JP2010014290A (en) * 2008-07-01 2010-01-21 Ihi Corp Multiple-chamber type heat treat furnace
JP4982726B2 (en) * 2010-04-12 2012-07-25 Dowaサーモテック株式会社 Heat treatment furnace
CN102252525A (en) * 2011-01-10 2011-11-23 朱海良 Improved structure of electric furnace pipe
JP6191780B2 (en) 2014-09-04 2017-09-06 Jfeスチール株式会社 Method for producing grain-oriented electrical steel sheet and nitriding equipment
CN104593577B (en) * 2015-01-07 2017-07-25 浙江正泰电器股份有限公司 A kind of integral heat-processing method and coil block of the coil block with bimetal leaf
CN105018117B (en) * 2015-07-27 2017-12-01 长兴嘉诚炉业有限公司 A kind of meat corpse continous way pyrolysis charring method
CN105256112A (en) * 2015-11-06 2016-01-20 浙江尚鼎工业炉有限公司 Continuous type aluminum magnesium alloy thermal treatment furnace
CN105331790A (en) * 2015-11-06 2016-02-17 浙江尚鼎工业炉有限公司 Continuous aluminum magnesium alloy thermal treatment furnace
CN106399656B (en) * 2016-03-21 2018-05-22 管敏富 A kind of conveying bracket for Al alloy parts heat treatment
CN105671249B (en) * 2016-03-21 2017-09-01 青岛凯利热处理有限公司 A kind of heat-conducting mechanism in heat-treatment furnace
CN112775388B (en) * 2021-01-29 2023-03-31 诸暨虹茂重工机械有限公司 Rotating assembly for forging heating furnace
WO2022218829A1 (en) * 2021-04-16 2022-10-20 Aerospace Transmission Technologies GmbH Method for the heat treatment of metal workpieces
EP4305369A1 (en) * 2021-04-16 2024-01-17 Aerospace Transmission Technologies GmbH Device for the heat treatment of metal workpieces
WO2022218831A1 (en) * 2021-04-16 2022-10-20 Aerospace Transmission Technologies GmbH Method for the heat treatment of metal workpieces

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5167212A (en) * 1974-12-09 1976-06-10 Daido Steel Co Ltd FUNIKINET SUSHORIRONO SOSAHOHO
JPS6127485A (en) * 1984-07-17 1986-02-06 中外炉工業株式会社 Continuous type atmosphere heat treatment furnace
JP2582554B2 (en) 1986-07-24 1997-02-19 大同特殊鋼株式会社 Method of carburizing steel
JPH01252886A (en) * 1988-03-31 1989-10-09 Central Glass Co Ltd Heat working furnace and heat treatment effected thereby
JPH0714353Y2 (en) * 1988-07-08 1995-04-05 中外炉工業株式会社 Roller hearth type heat treatment furnace
JPH0622358U (en) * 1992-07-28 1994-03-22 石川島播磨重工業株式会社 Annealing furnace
JP2001200311A (en) * 2000-01-19 2001-07-24 Nippon Steel Corp Hearth roll for heat treatment furnace of steel product
JP4305716B2 (en) * 2002-02-12 2009-07-29 Dowaホールディングス株式会社 Heat treatment furnace

Also Published As

Publication number Publication date
EP1589120A1 (en) 2005-10-26
JP2004183013A (en) 2004-07-02
WO2004050922A1 (en) 2004-06-17
EP1589120A4 (en) 2006-02-22
EP1589120B1 (en) 2012-06-06

Similar Documents

Publication Publication Date Title
JP4330111B2 (en) Heat treatment method and heat treatment furnace
KR100363813B1 (en) Gas carburization method and its apparatus
JP4305716B2 (en) Heat treatment furnace
JPH08285462A (en) Thermally treating device for metallic work under vacuum
JPS6116910B2 (en)
KR100324854B1 (en) Surface hardening and surface hardening of steel
JP2005009702A (en) Multi-cell type vacuum heat treating apparatus
JP6480423B2 (en) Conveyor furnace
CN209816207U (en) Steel pipe non-oxidation normalizing device
US2290551A (en) Heat treating furnace
US802517A (en) Furnace for the continuous heating of metal objects without oxidation.
JP2015025161A (en) Surface hardening method of iron or iron alloy and apparatus of the same, and surface hardening structure of iron or iron alloy
KR100906191B1 (en) The Hearth Roller type continuous carburizing heat treatment furnace
CN212174998U (en) Push rod type quenching furnace
KR101414253B1 (en) pressure nitriding heat treatment process
CN107217132A (en) The method for removing roller bottom type continuous spheroidizing annealing furnace inner product carbon
JP6922759B2 (en) Manufacturing method of steel parts
JP2009046700A (en) Heat treatment method and heat treatment facility
JPS6328853A (en) Batch type carburizing process
JP3553207B2 (en) Metal heat treatment equipment
JP4169299B2 (en) Atmosphere batch furnace
JP2998168B2 (en) High temperature nitrocarburizing furnace and nitrocarburizing method
JP2742074B2 (en) Carburizing furnace
JP2003183724A (en) Heat treatment furnace
CN104593580A (en) Method for preventing annealing carburization of high-speed tool steel cold-drawn steel wire

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050929

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080319

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20080519

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20090514

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20090615

R150 Certificate of patent or registration of utility model

Ref document number: 4330111

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120626

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120626

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130626

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees