JP2000144369A - Oxidation treatment of inside face of stainless steel tube - Google Patents
Oxidation treatment of inside face of stainless steel tubeInfo
- Publication number
- JP2000144369A JP2000144369A JP10312768A JP31276898A JP2000144369A JP 2000144369 A JP2000144369 A JP 2000144369A JP 10312768 A JP10312768 A JP 10312768A JP 31276898 A JP31276898 A JP 31276898A JP 2000144369 A JP2000144369 A JP 2000144369A
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- Prior art keywords
- stainless steel
- steel pipe
- heating furnace
- oxidizing
- gas
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体や医薬品、
食品の製造に使用されるオゾン含有水等の流体を搬送す
るために使用されるステンレス鋼管の内面を酸化処理す
る方法に関する。The present invention relates to semiconductors, pharmaceuticals,
The present invention relates to a method for oxidizing an inner surface of a stainless steel pipe used for conveying a fluid such as ozone-containing water used for manufacturing food.
【０００２】[0002]
【従来の技術】近年の半導体素子の製造においては、素
子の高集積化に伴い微細な加工がなされる。特に超ＬＳ
Ｉと称されるデバイスには、１μｍ以下の微細なパター
ンの加工が施されている。超ＬＳＩ製造プロセスでは、
使用されるガスや水の微量の不純物が配線パターンに付
着して回路不良の原因となる。したがって、超ＬＳＩの
ような半導体を製造するプロセスで使用するガスや水な
どの流体は、高純度なものでなければならない。2. Description of the Related Art In recent years, in the manufacture of semiconductor devices, fine processing is carried out with high integration of devices. Especially super LS
A device referred to as I is processed with a fine pattern of 1 μm or less. In the VLSI manufacturing process,
A trace amount of impurities such as gas and water used adhere to the wiring pattern and cause a circuit failure. Therefore, fluids such as gas and water used in a process for manufacturing a semiconductor such as an VLSI must have high purity.
【０００３】これらの流体を供給する配管や部材に対し
ても、流体に接触する面からの微粒子や不純物の放出が
極力少ないことが要求される。[0003] The pipes and members for supplying these fluids are also required to emit as little particulates and impurities as possible from the surface in contact with the fluid.
【０００４】最近、半導体製造工程等におけるシリコン
ウエハ等の洗浄には、オゾンを含有する洗浄水（オゾン
含有水）が用いられるようになってきた。オゾンは漂白
剤、殺菌剤として使用されていることからもわかるよう
に、強い酸化力を持っているので、金属をイオン化し、
有機物を分解する作用がある。そのため、オゾン含有超
純水でシリコンウエハ等を洗浄すると、それに付着して
いる金属はイオン化されることにより、また有機物は分
解されることにより除去される。さらにオゾンは、洗浄
後自己分解するため、シリコンウエハ上に汚染物として
残留することがない。このようにオゾン含有水はシリコ
ンウェハの洗浄に極めて有効である。Recently, cleaning water containing ozone (ozone-containing water) has been used for cleaning silicon wafers and the like in a semiconductor manufacturing process and the like. As can be seen from the fact that ozone is used as a bleach and disinfectant, it has a strong oxidizing power, so it ionizes metals,
Has the effect of decomposing organic matter. Therefore, when a silicon wafer or the like is washed with ozone-containing ultrapure water, the metal adhering to the silicon wafer is ionized, and the organic matter is removed by decomposition. Further, ozone is self-decomposed after cleaning, and therefore does not remain as a contaminant on the silicon wafer. Thus, ozone-containing water is extremely effective for cleaning silicon wafers.
【０００５】従来から使用されてきたステンレス鋼は、
半導体製造プロセスで使用される超純水の配管用および
装置部材として必要な強度を持っており、加工性にも優
れている。しかし、オゾンを含む水に対する耐食性に劣
るという欠点がある。すなわち、ステンレス鋼材がオゾ
ン含有超純水によって腐食され、鋼材からＦｅ、Ｃｒ、
Ｎｉなどの金属イオンが溶出し、オゾン含有水が汚染さ
れるという問題がある。 本発明者らは、ステンレス鋼
からオゾン含有水中へ金属イオンが溶出するのをを防止
する対策として、ステンレス鋼の鋼材表面にＡｌ酸化物
の皮膜を設けることを提案した（特開平１０−７２６４
５号公報）。Conventionally used stainless steel is
It has the necessary strength for piping of ultrapure water used in the semiconductor manufacturing process and as a member of equipment, and has excellent workability. However, there is a disadvantage that the corrosion resistance to water containing ozone is poor. That is, stainless steel material is corroded by ozone-containing ultrapure water, and Fe, Cr,
There is a problem that metal ions such as Ni are eluted and the ozone-containing water is contaminated. The present inventors have proposed to provide an aluminum oxide film on the surface of a stainless steel material as a measure to prevent elution of metal ions from the stainless steel into the ozone-containing water (Japanese Patent Laid-Open No. 10-7264).
No. 5).
【０００６】Ａｌ酸化物皮膜を備えた鋼材として、特開
平７−６００９９号公報に１０〜１５０オングストロー
ムのＡｌ酸化物皮膜を備えた超真空環境で使用されるス
テンレス鋼、および特開平６−２７１９９３号公報に自
動車排気ガス用部材等の高温用部品に適したＡｌ酸化物
皮膜を備えた耐酸化性に優れたオーステナイト系ステン
レス鋼が開示されている。As a steel material having an Al oxide film, Japanese Patent Application Laid-Open No. 7-60099 discloses a stainless steel used in an ultra-vacuum environment having an Al oxide film of 10 to 150 angstroms, and Japanese Patent Application Laid-Open No. 6-271993. The publication discloses an austenitic stainless steel excellent in oxidation resistance and provided with an Al oxide film suitable for high-temperature parts such as automobile exhaust gas members.
【０００７】また、ステンレス鋼管の内面に酸化皮膜を
形成させる装置が、特開平２−４３３５３号公報、およ
び特開平３−１１１５５２号公報に開示されている。Further, an apparatus for forming an oxide film on the inner surface of a stainless steel pipe is disclosed in JP-A-2-43353 and JP-A-3-111552.
【０００８】これらの酸化処理装置は、所定の雰囲気、
温度の加熱炉内に鋼管全体を挿入して固定し、鋼管内に
所定の組成のガスを流しながら、鋼管を外面から加熱す
る装置で、いわゆるバッチ方式の酸化処理方法である。[0008] These oxidation treatment apparatuses are provided with a predetermined atmosphere,
A device that heats a steel pipe from the outer surface while inserting and fixing the entire steel pipe into a heating furnace at a temperature, and flowing a gas having a predetermined composition into the steel pipe. This is a so-called batch type oxidation treatment method.
【０００９】しかしながら、従来のバッチ方式で、最も
多用されている外径が６．３５ｍｍで、長さが４ｍもあ
る長いステンレス鋼管を酸化処理する場合、次の２つの
問題がある。However, in the conventional batch method, when oxidizing a long stainless steel pipe having an outer diameter of 6.35 mm and a length of 4 m, which is most frequently used, there are the following two problems.
【００１０】１つは、酸化処理の能率が悪いことであ
る。すなわち、被処理鋼管の炉への取り付け、不活性ガ
スの流入による鋼管内に残留する空気のパージ、鋼管内
面に付着している水分を除去するためのベーキング、酸
化処理ガスへの切り替え、加熱処理、冷却および被処理
鋼管の取り外し、といった多工程をバッチ処理毎に繰り
返す必要がある。また、処理能率の改善を目的として、
１回で処理可能な鋼管本数を増やした場合には、装置が
複雑で高価になる。One is that the efficiency of the oxidation treatment is poor. That is, the steel pipe to be treated is attached to the furnace, purging of air remaining in the steel pipe due to inflow of an inert gas, baking for removing moisture adhering to the inner surface of the steel pipe, switching to an oxidizing gas, heating treatment , Cooling, and removal of the steel pipe to be treated need to be repeated for each batch process. Also, for the purpose of improving processing efficiency,
When the number of steel pipes that can be processed at one time is increased, the apparatus becomes complicated and expensive.
【００１１】もう一つの問題は、酸化物皮膜を鋼管全長
に渡って被膜厚を均一に形成させることができないこ
と、および被膜中のＡｌ含有量も均一にならないことで
ある。前述したオゾン含有水用配管として要求される性
能を確保するためには、この問題が解消されねばならな
い。Another problem is that the oxide film cannot be formed uniformly over the entire length of the steel pipe, and the Al content in the film is not uniform. This problem must be solved in order to secure the performance required for the ozone-containing water pipe described above.
【００１２】従来のバッチ式処理方法では、鋼管の全長
にわたって同時に酸化反応が起こるので、酸化性ガスが
導入される管端近傍が最も酸化されるのに対し、酸化性
ガスの出口となる管端近傍では酸化されにくくなり、鋼
管の長さ方向に不均一なＡｌ酸化物皮膜が生成されてし
まう。酸化性ガスの出口側の管端近傍が酸化されにくい
のは、酸化性ガスが導入される側の管端近傍部と比較し
て、ガス中の酸化性成分である水蒸気や酸素の濃度が低
くなっているからである。In the conventional batch processing method, an oxidation reaction occurs simultaneously over the entire length of the steel pipe, so that the vicinity of the pipe end into which the oxidizing gas is introduced is most oxidized, while the pipe end serving as the outlet of the oxidizing gas is oxidized. In the vicinity, oxidation becomes difficult, and a non-uniform Al oxide film is generated in the length direction of the steel pipe. The fact that the vicinity of the tube end on the outlet side of the oxidizing gas is hardly oxidized has a lower concentration of water vapor and oxygen, which are oxidizing components in the gas, than the vicinity of the tube end on the side where the oxidizing gas is introduced. Because it is.
【００１３】また、被膜中のＡｌ含有量が鋼管の長さ方
向に不均一となるのは次の理由による。The reason why the Al content in the coating becomes uneven in the longitudinal direction of the steel pipe is as follows.
【００１４】管内に導入された酸化性ガスは消費されな
がら導入側から出側へと移動する。したがって、出側管
端の近傍部の酸素分圧は、導入側の管端近傍部よりも低
くなるため、導入側と出側では形成される皮膜の組成が
異なる。すなわち、酸素分圧が低いと鋼中のＡｌのみが
酸化されるが、酸素分圧が高いとＣｒやＦｅも酸化され
る。そのため、ガス入り側管端部では酸化被膜中にＣｒ
やＦｅが混在してＡｌの含有量が低くなるが、ガス出側
管端に近づくに従いＡｌ含有量が高くなるといった現象
が生じる。The oxidizing gas introduced into the pipe moves from the introduction side to the exit side while being consumed. Therefore, the oxygen partial pressure in the vicinity of the outlet pipe end is lower than that in the vicinity of the inlet pipe end, so that the compositions of the films formed on the inlet side and the outlet side are different. That is, when the oxygen partial pressure is low, only Al in the steel is oxidized, but when the oxygen partial pressure is high, Cr and Fe are also oxidized. Therefore, at the end of the gas inlet tube, Cr
Al and Fe are mixed to lower the Al content, but a phenomenon occurs in which the Al content increases as approaching the gas outlet tube end.
【００１５】[0015]
【発明が解決しようとする課題】本発明の課題は、半導
体、医薬品や食品の製造においてオゾン含有水等の流体
を搬送するために使用されるステンレス鋼管の内面に、
能率良く、しかもＡｌ含有量と膜厚が均一なＡｌ酸化物
皮膜を鋼管全長に形成する酸化処理方法を提供すること
である。SUMMARY OF THE INVENTION An object of the present invention is to provide an inner surface of a stainless steel pipe used for conveying a fluid such as ozone-containing water in the production of semiconductors, pharmaceuticals and foods.
An object of the present invention is to provide an oxidation treatment method for efficiently forming an Al oxide film having a uniform Al content and film thickness over the entire length of a steel pipe.
【００１６】[0016]
【課題を解決するための手段】本発明の要旨は以下の通
りである。The gist of the present invention is as follows.
【００１７】（１）水素：１０〜９９．９９９９体積
％、水蒸気：０．５〜３０体積ｐｐｍを含み、残部が不
活性ガスからなる酸化性混合ガスを、重量％でＡｌを１
〜６％含有するステンレス鋼管内に流しつつ、加熱炉内
に前記ステンレス鋼管を挿入し、その長手方向に移動さ
せながら８００〜１２００℃に加熱して、ステンレス鋼
管の内面にＡｌ酸化物被膜を形成させるステンレス鋼管
内面の酸化処理方法。(1) An oxidizing mixed gas containing 10 to 99.9999% by volume of hydrogen and 0.5 to 30 ppm by volume of steam and the balance consisting of an inert gas is mixed with 1% by weight of Al.
The stainless steel pipe is inserted into a heating furnace while flowing into a stainless steel pipe containing 6%, and heated to 800 to 1200 ° C. while moving in the longitudinal direction to form an Al oxide film on the inner surface of the stainless steel pipe. The oxidation treatment method for the inner surface of the stainless steel pipe.
【００１８】（２）加熱炉の入り口近傍、加熱炉内およ
び加熱炉出口近傍においてステンレス鋼管の外面が酸化
しないように、ステンレス鋼管のパスライン周辺を非酸
化性雰囲気とする上記（１）記載のステンレス鋼管内面
の酸化処理方法。(2) The non-oxidizing atmosphere around the stainless steel pipe pass line so that the outer surface of the stainless steel pipe is not oxidized near the entrance of the heating furnace, inside the heating furnace and near the heating furnace outlet. Oxidation treatment method for the inner surface of stainless steel pipe.
【００１９】（３）非酸化性雰囲気のチャンバ内に加熱
炉を設けることによりステンレス鋼管のパスライン周辺
を非酸化性雰囲気とする上記（２）記載のステンレス鋼
管内面の酸化処理方法。(3) The method for oxidizing the inner surface of a stainless steel pipe according to the above (2), wherein a heating furnace is provided in a chamber in a non-oxidizing atmosphere to make the periphery of the pass line of the stainless steel pipe a non-oxidizing atmosphere.
【００２０】（４）加熱炉よりも長いマッフルを備えた
加熱炉を用い、マッフル内を非酸化性雰囲気とすること
により、テンレス鋼管のパスライン周辺を非酸化性雰囲
気とする上記（２）のステンレス鋼管内面の酸化処理方
法。(4) The heating furnace having a muffle longer than the heating furnace is used, and the inside of the muffle is made a non-oxidizing atmosphere, so that the periphery of the pass line of the stainless steel pipe is made a non-oxidizing atmosphere. Oxidation treatment method for the inner surface of stainless steel pipe.
【００２１】（５）ステンレス鋼管内に流す酸化性混合
ガスの流量が下記式を満足する量である上記（１）、
（２）、（３）および（４）記載のステンレス鋼管内面
の酸化処理方法。(5) The above (1), wherein the flow rate of the oxidizing mixed gas flowing in the stainless steel pipe is an amount satisfying the following equation:
(2) The method for oxidizing the inner surface of a stainless steel pipe according to (3) or (4).
【００２２】酸化性混合ガスの流量（リットル／分）≧８．
２６×Ｒ×（Ｌ／Ｔ）／Ｃ ここで、 Ｒ：ステンレス鋼管の内径（ｍｍ） Ｌ：加熱炉均熱帯長さ（ｃｍ） Ｔ：ステンレス鋼管の均熱帯での酸化処理時間（分） Ｃ：酸化性ガス中の水蒸気濃度（体積ｐｐｍ） 本発明者らは、従来のバッチ式の酸化処理方法の欠点を
解消すべく種々実験、検討した結果以下の知見を得て本
発明を完成するに至った。Flow rate of oxidizing mixed gas (liter / minute) ≧ 8.
26 × R × (L / T) / C where: R: inner diameter of stainless steel pipe (mm) L: soaking length of heating furnace (cm) T: oxidation treatment time of stainless steel pipe in soaking (min) C : Steam concentration in oxidizing gas (volume ppm) The present inventors have conducted various experiments and studies to solve the drawbacks of the conventional batch-type oxidation treatment method. Reached.
【００２３】ａ）ステンレス鋼管内面にオゾンを含有す
る超純水に対する耐食性を付与して金属イオンの溶出を
防止するには、Ａｌの含有率が９０原子％以上で、厚さ
が１０〜２００ｎｍのＡｌ酸化物皮膜をステンレス鋼管
内面に形成するのが好ましい。 ｂ）そのようなＡｌ酸
化物被膜を形成するのに用いる酸化性ガスとして好適な
のは、水素：１０〜９９．９９９９体積％、水蒸気：
０．５〜３０体積ｐｐｍを含み残部が不活性ガスからな
る酸化性混合ガスであり、８００〜１２００℃の温度範
囲内で酸化処理するのがよい。A) To impart corrosion resistance to ultrapure water containing ozone on the inner surface of the stainless steel pipe to prevent elution of metal ions, the content of Al should be 90 atomic% or more and the thickness should be 10 to 200 nm. It is preferable to form an Al oxide film on the inner surface of the stainless steel pipe. b) Suitable oxidizing gases used to form such Al oxide coatings are hydrogen: 10-99.9999% by volume, water vapor:
It is an oxidizing mixed gas containing 0.5 to 30 ppm by volume and the balance being an inert gas, and is preferably oxidized within a temperature range of 800 to 1200 ° C.
【００２４】ｃ）鋼管の長手方向に厚さが均一になるよ
うにＡｌ酸化物皮膜を生成させ、しかも酸化物被膜中の
Ａｌ量を均一にするには、酸化性混合ガスを鋼管内に流
しつつ、加熱炉内で鋼管をその長手方向に移動させなが
ら酸化処理するのがよい。C) In order to form an Al oxide film so as to have a uniform thickness in the longitudinal direction of the steel pipe and to make the amount of Al in the oxide film uniform, an oxidizing mixed gas is passed through the steel pipe. In addition, the oxidation treatment is preferably performed while moving the steel pipe in the heating furnace in the longitudinal direction.
【００２５】[0025]
【発明の実施の形態】以下、本発明の酸化処理方法を具
体的に説明する。BEST MODE FOR CARRYING OUT THE INVENTION The oxidation treatment method of the present invention will be specifically described below.
【００２６】図１は、本発明の酸化処理方法を実施する
のに使用する酸化処理装置の一例を示す概略縦断面図で
ある。FIG. 1 is a schematic longitudinal sectional view showing an example of an oxidation treatment apparatus used to carry out the oxidation treatment method of the present invention.
【００２７】チャンバ３の中に加熱炉５が設けられてお
り、管継ぎ手９により接続されたステンレス鋼管１ａ、
１ｂが図示しない鋼管移動装置により所定の速度でチャ
ンバ、加熱炉内に挿入され、その長手方向に移動され
る。ステンレス鋼管内には管の後端に取り付けられた酸
化性ガス供給口８から酸化性ガス２が供給される。ま
た、チャンバ内には非酸化性ガス４がチャンバの供給口
７ａから供給され、必要により７ｂから排出される。A heating furnace 5 is provided in the chamber 3 and includes stainless steel pipes 1a,
1b is inserted into a chamber and a heating furnace at a predetermined speed by a steel pipe moving device (not shown), and is moved in the longitudinal direction thereof. The oxidizing gas 2 is supplied into the stainless steel pipe from an oxidizing gas supply port 8 attached to the rear end of the pipe. The non-oxidizing gas 4 is supplied into the chamber from a supply port 7a of the chamber, and is discharged from the chamber 7b if necessary.
【００２８】図１に示した例では、ステンレス鋼管を長
手方向に２本接続した例であるが、多数の鋼管を接続し
てもよく、また接続した鋼管を複数本同時に炉内で処理
すればより効率がよくなる。In the example shown in FIG. 1, two stainless steel pipes are connected in the longitudinal direction. However, a large number of steel pipes may be connected, and if a plurality of connected steel pipes are processed simultaneously in a furnace. More efficient.
【００２９】複数の鋼管を長手方向に接続する場合、管
の継ぎ手部からの管外雰囲気ガスの混入を避けるため、
気密性のある接続法が必要である。具体的には、溶接や
金属ガスケット式機械継ぎ手、食い込み式機械継ぎ手等
が例示される。When connecting a plurality of steel pipes in the longitudinal direction, in order to avoid mixing of extraneous atmospheric gas from the joints of the pipes,
An airtight connection method is required. Specific examples include a mechanical joint of a welding or metal gasket type and a mechanical joint of a bite type.
【００３０】加熱炉で加熱された管の内面で酸化反応が
起こり始める。加熱炉３に搬入される前の管の温度は、
酸化性ガスが反応しない温度にしておく、通常は常温で
あればよい。また、加熱炉５内で酸化処理が終了して炉
外へ排出された管の外面が大気によって酸化されるのを
防止するために、加熱炉５からチャンバ外へ出るまでの
距離を約２ｍ以上にして、酸化反応が起こらない程度の
温度まで管を徐冷した後にチャンバ外へ排出するのが望
ましい。An oxidation reaction starts on the inner surface of the tube heated in the heating furnace. The temperature of the tube before being carried into the heating furnace 3 is
The temperature at which the oxidizing gas does not react is usually set at room temperature. Further, in order to prevent the outer surface of the tube discharged outside the furnace after the oxidation treatment in the heating furnace 5 from being oxidized by the atmosphere, the distance from the heating furnace 5 to the outside of the chamber is about 2 m or more. Then, it is desirable that the tube is gradually cooled to a temperature at which an oxidation reaction does not occur, and then discharged out of the chamber.
【００３１】以下、本発明の酸化処理方法で規定した各
条件について説明する。The conditions specified in the oxidation treatment method of the present invention will be described below.
【００３２】１）ステンレス鋼管、Ａｌ含有量 ステンレス鋼管は鋼種に限定されるものでなく、オース
テナイト系ステンレス鋼管、フェライト系ステンレス鋼
管および２相系ステンレス鋼管が対象となる。1) Stainless Steel Pipe and Al Content The stainless steel pipe is not limited to the type of steel, but includes austenitic stainless steel pipe, ferritic stainless steel pipe, and two-phase stainless steel pipe.
【００３３】しかし、Ａｌ酸化物被膜を生成させるの
で、Ａｌ含有量は、重量％で１〜６％含有させる必要が
ある。１％未満では、本発明の方法で酸化処理してもオ
ゾン含有超純水に金属イオンを溶出させないＡｌ酸化物
被膜が得られない。一方、６％を超えると金属間化合物
が析出して熱間加工性および靭性が劣化する。したがっ
て、Ａｌ含有量は、１〜６％とした。However, since an Al oxide film is formed, the Al content must be 1 to 6% by weight. If it is less than 1%, an Al oxide film that does not elute metal ions into ozone-containing ultrapure water cannot be obtained even if the oxidation treatment is performed by the method of the present invention. On the other hand, if it exceeds 6%, the intermetallic compound precipitates and the hot workability and toughness deteriorate. Therefore, the Al content was set to 1 to 6%.
【００３４】対象とするステンレス鋼の好ましい化学組
成は以下の通りである。The preferred chemical composition of the target stainless steel is as follows:
【００３５】重量％で、Ｃｒ：１２〜３０％、Ｎｉ：０
〜３５％、Ａｌ：１〜６％、Ｓｉ：０．３％以下、Ｍ
ｏ：０〜３％、Ｂ＋Ｌａ＋Ｃｅ：０〜０．０１％、Ｃ
ｕ：０．１％以下、Ｎｂ＋Ｔｉ＋Ｚｒ：０．１％以下、
Ｃ：０．０３％以下、Ｍｎ：０．２％以下、Ｐ：０．０
３％以下、Ｓ：０．０１％以下、Ｎ：０．０５％以下、
Ｏ：０．０１％以下、残部：Ｆｅおよび不可避的不純
物。Cr: 12 to 30%, Ni: 0% by weight
-35%, Al: 1-6%, Si: 0.3% or less, M
o: 0 to 3%, B + La + Ce: 0 to 0.01%, C
u: 0.1% or less, Nb + Ti + Zr: 0.1% or less,
C: 0.03% or less, Mn: 0.2% or less, P: 0.0
3% or less, S: 0.01% or less, N: 0.05% or less,
O: 0.01% or less, balance: Fe and inevitable impurities.
【００３６】上記のステンレス鋼のなかでも、Ｎｉ含有
率が重量％で０〜５％のフェライト系ステンレス鋼、Ｃ
ｒ、ＮｉおよびＳｉ含有率が重量％でＣｒ：１２〜２５
％、Ｎｉ：１４〜３５％、Ｓｉ：０．２％以下であるオ
ーステナイト系ステンレス鋼材などが実用上もっとも好
適である。Among the above stainless steels, ferritic stainless steel having a Ni content of 0 to 5% by weight,
The content of r, Ni and Si is expressed in terms of wt.
%, Ni: 14 to 35%, and Si: 0.2% or less are most practically suitable.
【００３７】２）酸化性混合ガス （ａ）水素含有量 水素含有率が１０体積％未満では、酸化反応がおきてい
る際の管内の水蒸気含有率のわずかな変化で酸化挙動が
大きく変化し、Ａｌ含有率が高くて均一な厚さのＡｌ酸
化物皮膜を安定して形成することができない。一方、９
９．９９９９体積％を超えると高価になり経済的でない
ため、上限を９９．９９９９体積％とした。 （ｂ）水蒸気 水蒸気の含有量が０．５体積ｐｐｍ未満では、Ａｌ酸化
物皮膜を十分に形成することができない。３０体積ｐｐ
ｍを超えて含有させると、Ａｌ酸化物皮膜厚が２００ｎ
ｍを超える程に成長し、管内面が粗くなる。均一な厚さ
を保ち、かつＡｌ含有量が高いＡｌ酸化物皮膜を形成す
るためには、水蒸気の含有量を０．５〜２０体積ｐｐｍ
とするのがよい。さらに好ましくは、１〜１０体積ｐｐ
ｍである。2) Oxidizing mixed gas (a) Hydrogen content If the hydrogen content is less than 10% by volume, the oxidation behavior changes greatly due to a slight change in the water vapor content in the tube during the oxidation reaction. An Al oxide film having a high Al content and a uniform thickness cannot be formed stably. On the other hand, 9
If it exceeds 9.9999% by volume, it is expensive and uneconomical, so the upper limit was 99.9999% by volume. (B) Water vapor When the content of water vapor is less than 0.5 ppm by volume, an Al oxide film cannot be sufficiently formed. 30 volume pp
m, the Al oxide film thickness is 200 n
m so that the inner surface of the tube becomes rough. In order to maintain a uniform thickness and form an Al oxide film having a high Al content, the content of water vapor should be 0.5 to 20 ppm by volume.
It is good to do. More preferably, 1 to 10 volume pp
m.
【００３８】（ｃ）不活性ガス 水蒸気および水素以外の混合ガスは不活性ガスとする。
不活性ガスとしては、ヘリウムガス、アルゴンガス、ネ
オンガス等を用いることができる。これらのガスのう
ち、安価なアルゴンガスを使用するのが好ましい。水素
ガスおよび不活性ガスの含有量は流量制御器により、水
蒸気は露点計測と水蒸気添加器により調整することがで
きる。(C) Inert gas A mixed gas other than steam and hydrogen is an inert gas.
As the inert gas, helium gas, argon gas, neon gas, or the like can be used. Of these gases, it is preferable to use inexpensive argon gas. The content of hydrogen gas and inert gas can be adjusted by a flow controller, and the content of steam can be adjusted by dew point measurement and a steam adder.
【００３９】３）ステンレス鋼管の加熱温度 ステンレス鋼管の加熱温度は、８００〜１２００℃とす
る。８００℃未満ではＡｌ含有率が９０％以下の薄い酸
化物被膜しか形成できない。一方、１２００℃を超える
と酸化の進行が速いために皮膜が過度に厚くなる。好ま
しい加熱温度は８５０〜１１００℃である。3) Heating temperature of the stainless steel pipe The heating temperature of the stainless steel pipe is 800 to 1200 ° C. Below 800 ° C., only a thin oxide film having an Al content of 90% or less can be formed. On the other hand, when the temperature exceeds 1200 ° C., the progress of oxidation is so rapid that the film becomes excessively thick. A preferred heating temperature is 850 to 1100 ° C.
【００４０】４）酸化性ガスの流量 Ａｌの含有率が９０原子％以上で、厚さが１０〜２００
ｎｍのＡｌ酸化物皮膜をステンレス鋼管内面に形成する
ためには、上述した加熱温度および酸化性ガスの組成に
加え、酸化性ガスの流量を下記の式を満足する量とする
のが好ましい。酸化物皮膜の酸素源となるのに十分な量
の酸素を含有する酸化性ガスを管内に供給する必要があ
る。管内面にＡｌ酸化物（Ａｌ2Ｏ3、分子量１０１．９
３、密度 ３．９９ｇ／ｃｍ3）を最低１０ｎｍ生成させ
るためには、皮膜中とガス中の酸素量を比較する計算か
ら、酸化性ガス流量の必要下限は次式で表される。4) Flow rate of oxidizing gas The Al content is 90 atomic% or more and the thickness is 10 to 200
In order to form an Al oxide film having a thickness of nm on the inner surface of the stainless steel pipe, it is preferable that the flow rate of the oxidizing gas be an amount satisfying the following expression in addition to the above-mentioned heating temperature and the composition of the oxidizing gas. An oxidizing gas containing a sufficient amount of oxygen to serve as an oxygen source for the oxide film must be supplied into the tube. Al oxide (Al 2 O 3 , molecular weight 101.9)
3. In order to generate a density of 3.99 g / cm 3 ) of at least 10 nm, the necessary lower limit of the oxidizing gas flow rate is expressed by the following equation from a calculation comparing the amount of oxygen in the film and the amount of oxygen in the gas.
【００４１】酸化性ガスの流量（リットル／分）≧８．
２６×Ｒ×（Ｌ／Ｔ）／Ｃ Ｒ：ステンレス鋼管内径（ｃｍ） Ｌ：加熱炉均熱帯長さ（ｃｍ） Ｔ：ステンレス鋼管の均熱帯での処理時間（分） Ｃ：酸化性ガス中の水蒸気濃度（体積ｐｐｍ） 加熱炉均帯長さ（Ｌ）とは、加熱炉内で加熱目標温度に
なっている部分の長さである。加熱炉の均熱帯の長さ
（Ｌ）は、例えば、複数の加熱ゾーンを持つヒーターを
使用して、加熱ゾーンの長さを変えることにより変更す
ることができる。鋼管の均熱帯での処理時間（Ｔ）は、
鋼管の任意の点が加熱炉均熱帯を通過する時間である。Flow rate of oxidizing gas (liter / minute) ≧ 8.
26 × R × (L / T) / C R: Inner diameter of stainless steel pipe (cm) L: Length of heating furnace soaking zone (cm) T: Processing time of stainless steel tube in soaking zone (min) C: In oxidizing gas The water vapor concentration (volume ppm) of the heating furnace uniform zone length (L) is the length of the portion of the heating furnace at the heating target temperature. The length (L) of the soaking zone of the heating furnace can be changed by changing the length of the heating zone, for example, using a heater having a plurality of heating zones. The processing time (T) of the steel pipe in the soaking zone is
It is the time at which any point on the steel tube passes through the furnace soak.
【００４２】処理時間（Ｔ）は、１〜６０分の範囲に設
定するのが好ましい。１分未満では膜厚が不足すること
があり、また６０分を超えると皮膜が過度に厚くなると
ともに酸化処理の能率が低下する。The processing time (T) is preferably set in the range of 1 to 60 minutes. If the time is less than 1 minute, the film thickness may be insufficient. If the time exceeds 60 minutes, the film becomes excessively thick and the efficiency of the oxidation treatment is reduced.
【００４３】酸化性ガスの水蒸気濃度（Ｃ）は、管内面
にＡｌ酸化物皮膜を必要最低限である１０ｎｍ以上の厚
さに生成させることを目標とし、酸化反応に必要な酸素
は全て酸化性ガス中の水蒸気から供給されると見なして
設定する値である。The water vapor concentration (C) of the oxidizing gas is aimed at forming an Al oxide film on the inner surface of the tube to a minimum thickness of 10 nm or more. This is a value set assuming that the gas is supplied from the water vapor in the gas.
【００４４】管の移動速度は、処理時間Ｔと加熱炉均熱
帯長さＬから、Ｌ／Ｔにより得られた値となる。The moving speed of the pipe is a value obtained by L / T from the processing time T and the heating furnace uniform tropical length L.
【００４５】上記の式から分かるように、酸化性ガスの
流量は、鋼管内径、加熱炉中の均熱長さが長いほど、ま
た処理時間と水蒸気濃度が小さいほど多くなる。上記の
式で求められる値に満たない流量では、反応に使用され
る酸化性ガスが不足するため、鋼管内面の微視的凹凸を
考慮した場合に、前述した機能を発揮するのに必要な最
低膜厚１０ｎｍ以上のＡｌ酸化物皮膜が鋼管全長にわた
って形成されないことがある。一方、酸化性ガスを必要
以上に供給することは、ガスのコストを上昇させるので
好ましくない。流量の上限値は、下限値の３倍以内とす
るのが好ましい。As can be seen from the above equation, the flow rate of the oxidizing gas increases as the inner diameter of the steel pipe and the soaking length in the heating furnace are longer, and the processing time and the steam concentration are smaller. At a flow rate less than the value obtained by the above equation, the oxidizing gas used for the reaction is insufficient, so that taking into account the microscopic unevenness on the inner surface of the steel pipe, the minimum necessary for exerting the above-described function is considered. An Al oxide film having a thickness of 10 nm or more may not be formed over the entire length of the steel pipe. On the other hand, supplying an oxidizing gas more than necessary is not preferable because it increases the cost of the gas. It is preferable that the upper limit of the flow rate be within three times the lower limit.
【００４６】また、ガス圧力に関しては、鋼管の継ぎ手
部分あるいは鋼管前方先端からの空気あるいは非酸化性
ガスの混入を防ぐために、鋼管内ガスの圧力を大気圧お
よび加熱炉内圧より高めにしておく。具体的には、０．
２ｋｇｆ／ｃｍ2 以上、好ましくは０．５ｋｇｆ／ｃｍ
2 以上とする。鋼管の内圧は、鋼管が細径の場合は、
鋼管内抵抗により上昇するので、特に昇圧の手段は必要
ない。しかし、鋼管径が大きな、具体的には外径１２．
７ｍｍ（１／２インチ）以上の場合には、鋼管先端を小
径化するためのオリフィス（図１の６）を取り付けて昇
圧するのがよい。As for the gas pressure, the pressure of the gas in the steel pipe is higher than the atmospheric pressure and the internal pressure of the heating furnace in order to prevent air or non-oxidizing gas from entering from the joint portion of the steel pipe or the front end of the steel pipe. Specifically, 0.
2 kgf / cm 2 or more, preferably 0.5 kgf / cm
2 or more. If the steel pipe has a small diameter,
Since the pressure rises due to the resistance in the steel pipe, no particular means for increasing the pressure is required. However, the diameter of the steel pipe is large, specifically, the outer diameter is 12.
In the case of 7 mm (１ ／ inch) or more, it is preferable to increase the pressure by attaching an orifice (6 in FIG. 1) for reducing the diameter of the tip of the steel pipe.
【００４７】５）Ａｌ酸化物皮膜 ステンレス鋼管の内面にＡｌ酸化物皮膜（Ａｌ2Ｏ3）を
生成させるのは、前記したようにオゾンを含有する超純
水に対する耐食性を付与し、オゾン含有超純水への金属
イオンの溶出を防止するためである。Ａｌ酸化物被膜
は、Ａｌの含有率が９０原子％以上、厚さが１０〜２０
０ｎｍとするのが好ましい。なお、Ａｌ酸化物被膜は、
全てがＡｌ酸化物からなっているのが好ましいが、その
ような酸化物被膜を生成させることは困難であり、Ｃｒ
およびＦｅ等の酸化物を含むものとするが、それらはで
きるだけ少ないのが好ましい。5) Al Oxide Coating The formation of the Al oxide coating (Al 2 O 3 ) on the inner surface of the stainless steel pipe is achieved by imparting corrosion resistance to ozone-containing ultrapure water as described above. This is to prevent elution of metal ions into pure water. The Al oxide film has an Al content of 90 atomic% or more and a thickness of 10 to 20.
It is preferably set to 0 nm. The Al oxide film is
It is preferred that all are made of Al oxide, but it is difficult to form such an oxide film,
And oxides such as Fe, but it is preferable that they be as small as possible.
【００４８】６）酸化性ガスをステンレス鋼管内に流し
つつ、鋼管を加熱炉内を移動させながらの酸化処理 ステンレス鋼管の長手方向に厚さが均一になるようにＡ
ｌ酸化物皮膜を生成させること、および酸化物被膜中の
Ａｌ量を均一にするために酸化性混合ガスを鋼管内に流
しつつ、加熱炉内で鋼管をその長手方向に移動させなが
ら酸化処理する。6) Oxidizing treatment while flowing the oxidizing gas into the stainless steel tube while moving the steel tube in the heating furnace. A so that the thickness of the stainless steel tube becomes uniform in the longitudinal direction.
(1) Oxidizing treatment is performed while moving the steel pipe in the longitudinal direction in a heating furnace while flowing an oxidizing mixed gas into the steel pipe in order to generate an oxide film and to make the amount of Al in the oxide film uniform. .
【００４９】このような方法により酸化処理をおこなう
と、鋼管の長手方向のどの位置でも加熱炉内での酸化処
理条件が同じになるため、酸化物被膜厚および被膜中の
Ａｌ含有量が均一となる。When the oxidation treatment is performed by such a method, the oxidation treatment conditions in the heating furnace are the same at any position in the longitudinal direction of the steel pipe, so that the oxide coating thickness and the Al content in the coating are uniform. Become.
【００５０】７）非酸化性雰囲気 外表面が酸化したステンレス鋼管は、酸化皮膜の剥離に
よる不純物が発生するため、清浄度が要求される半導体
や医薬品、食品の製造に使用される配管には適さない。
したがって、酸化処理中にステンレス鋼管の外面が酸化
するのを防止するために、加熱炉の入り口近傍、加熱炉
内および加熱炉出口近傍のステンレス鋼管のパスライン
周辺を非酸化性雰囲気にするのが好ましい。非酸化雰囲
気にするには図１に示した手段がある。7) Non-oxidizing atmosphere Since the stainless steel pipe whose outer surface is oxidized generates impurities due to peeling of the oxide film, it is suitable for pipes used in the production of semiconductors, pharmaceuticals, and foods that require cleanliness. Absent.
Therefore, in order to prevent the outer surface of the stainless steel pipe from being oxidized during the oxidation treatment, the non-oxidizing atmosphere should be set around the stainless steel pipe pass line near the entrance of the heating furnace, inside the heating furnace, and near the heating furnace outlet. preferable. There is a means shown in FIG. 1 for making a non-oxidizing atmosphere.
【００５１】図２は、ステンレス鋼管のパスライン周辺
を非酸化性雰囲気にする他の方法を示す図である。すな
わち、加熱炉５内に加熱炉よりも長いマッフル１０を挿
入してマッフル内を非酸化性雰囲気とする方法で、上記
チャンバを用いるより簡単な装置となる利点がある。FIG. 2 is a view showing another method of setting the periphery of the pass line of the stainless steel pipe to a non-oxidizing atmosphere. That is, a method in which the muffle 10 longer than the heating furnace is inserted into the heating furnace 5 to make the inside of the muffle a non-oxidizing atmosphere has an advantage that a simpler apparatus using the above chamber can be obtained.
【００５２】非酸化性雰囲気は、酸素濃度３体積ｐｐｍ
以下で且つ水蒸気濃度３０体積ｐｐｍ以下の水素ガスや
アルゴンなどの不活性ガス、さらに好ましくは酸素濃度
１体積ｐｐｍ以下且つ水蒸気濃度１０体積ｐｐｍ以下の
水素ガスやアルゴンなどの不活性ガスを用いるのがよ
い。The non-oxidizing atmosphere has an oxygen concentration of 3 vol ppm
It is preferable to use an inert gas such as hydrogen gas or argon having a water vapor concentration of 30 vol ppm or less, and more preferably an inert gas such as a hydrogen gas or argon having an oxygen concentration of 1 vol ppm or less and a water vapor concentration of 10 vol ppm or less. Good.
【００５３】[0053]
【実施例】表１に示す２種の化学組成を有するオーステ
ナイト系ステンレス鋼から表２に示す３種類の寸法のス
テンレス鋼管を通常の方法で製造した。これらの鋼管に
表３に示す諸条件で酸化処理を施した。酸化処理は図１
に示した装置を用いておこなった。EXAMPLES Stainless steel pipes of three dimensions shown in Table 2 were produced from austenitic stainless steel having two chemical compositions shown in Table 1 by a usual method. These steel pipes were subjected to oxidation treatment under various conditions shown in Table 3. The oxidation treatment is shown in FIG.
This was performed using the apparatus shown in FIG.
【００５４】[0054]
【表１】 [Table 1]
【００５５】[0055]
【表２】 [Table 2]
【００５６】[0056]
【表３】 [Table 3]
【００５７】チャンバ内の非酸化性雰囲気は、水分を含
まない水素とした。The non-oxidizing atmosphere in the chamber was hydrogen containing no water.
【００５８】表３のNo.１〜１３は、本発明の方法によ
る酸化処理を施したものである。No.１４〜２０は本発
明で規定する条件から外れている方法で酸化処理を施し
たものである。また、No.１９ は、加熱炉内で鋼管を移
動させないで固定したまま酸化処理したもので、バッチ
方法に類似している（従来のバッチ方法では、鋼管全体
が同時に加熱されて酸化処理される）。Nos. 1 to 13 in Table 3 have been subjected to oxidation treatment by the method of the present invention. Nos. 14 to 20 have been subjected to an oxidation treatment by a method deviating from the conditions specified in the present invention. In addition, No. 19 is obtained by oxidizing the steel pipe in a heating furnace while keeping the steel pipe fixed without moving it, which is similar to the batch method. (In the conventional batch method, the entire steel pipe is heated and oxidized at the same time. ).
【００５９】加熱炉雰囲気が鋼管内へ混入することを防
止するために、酸化性ガスの出側には口径３ｍｍのオリ
フィス６を取り付けた。In order to prevent the atmosphere of the heating furnace from being mixed into the steel pipe, an orifice 6 having a diameter of 3 mm was attached to the outlet side of the oxidizing gas.
【００６０】酸化処理後の鋼管内面のＡｌ酸化物皮膜の
性状は次のようにして評価した。The properties of the Al oxide film on the inner surface of the steel pipe after the oxidation treatment were evaluated as follows.
【００６１】鋼管の端部から長さ１００ｃｍ毎の計５ヶ
所をマークし、酸化性ガスを導入した鋼管の入口部を位
置１とし、酸化性ガスの出口である鋼管の端部を位置５
とし、中間部を順に位置２、３、４とした。それぞれの
位置の鋼管の部分を縦半割りにして試験片を切り出し、
鋼管の内面に形成されているＡｌ酸化物皮膜を膜厚方向
に窒素イオンスパッタリングによる２次イオン質量分析
をおこなって、Ａｌ含有量と膜厚を測定した。A total of five points of 100 cm in length were marked from the end of the steel pipe, the inlet of the steel pipe into which the oxidizing gas was introduced was designated as position 1, and the end of the steel pipe as the outlet of the oxidizing gas was designated as position 5.
, And the intermediate portion was positioned at positions 2, 3, and 4 in that order. Cut the test piece by dividing the steel pipe part at each position in half vertically,
The Al oxide film formed on the inner surface of the steel pipe was subjected to secondary ion mass spectrometry by nitrogen ion sputtering in the thickness direction to measure the Al content and the film thickness.
【００６２】酸化処理後の鋼管内面の耐オゾン含有水性
は以下の方法で評価した。The ozone-resistant water content of the inner surface of the steel pipe after the oxidation treatment was evaluated by the following method.
【００６３】鋼管内部に、オゾン１１０ｇ／ｍ3 を含
む８０℃の酸素と比抵抗１６ＭΩｃｍの超純水を封入し
１００時間保持した。この場合、超純水は約７ｍｇ／ｌ
のオゾンを含むオゾン含有水となる。次に、このオゾン
含有水を誘導結合プラズマイオン質量分析法により定量
分析し、オゾン含有水中に溶出した金属イオン量（Ｆｅ
イオン、Ｃｒイオン、Ｎｉイオン、Ａｌイオンの総和）
を求めた。この結果をもとに、鋼管内面の表面積当たり
の金属イオン溶出量を換算し、耐オゾン水性を評価し
た。溶出量が０．５ｍｇ／ｍ2未満の場合は良好、０．
５ｍｇ／ｍ2以上２．０ｍｇ／ｍ2未満の場合は普通、
２．０ｍｇ／ｍ2以上の場合は不良とした。なお、表３
にはそれぞれ、○、△、×で表示した。In a steel tube, oxygen at 80 ° C. containing ozone at 110 g / m 3 and ultrapure water having a specific resistance of 16 MΩcm were sealed and kept for 100 hours. In this case, the ultrapure water is about 7 mg / l
Water containing ozone. Next, the ozone-containing water was quantitatively analyzed by inductively coupled plasma ion mass spectrometry, and the amount of metal ions (Fe
Ion, Cr ion, Ni ion, Al ion)
I asked. Based on this result, the amount of metal ions eluted per surface area of the inner surface of the steel pipe was converted to evaluate ozone water resistance. Good when the elution amount is less than 0.5 mg / m 2 ,
In the case of 5 mg / m 2 or more and less than 2.0 mg / m 2 ,
When it was 2.0 mg / m 2 or more, it was determined to be defective. Table 3
Are indicated by ○, Δ, and ×, respectively.
【００６４】結果を表４に示す。Table 4 shows the results.
【００６５】[0065]
【表４】 [Table 4]
【００６６】本発明例である No.１〜１３は、鋼管の径
および長さ方向の位置によらず、Ａｌ含有量が９０％を
超え、膜厚１０ｎｍ〜２００ｎｍのＡｌ酸化物皮膜が生
成していた。また、耐オゾン含有水性も良好であった。In Nos. 1 to 13 of the present invention, the Al content exceeded 90% and an Al oxide film having a film thickness of 10 nm to 200 nm was formed irrespective of the position in the diameter and length direction of the steel pipe. I was Further, the ozone-resistant water content was also good.
【００６７】これに対し、水蒸気含有率、水素含有率、
鋼管の加熱温度のいずれかが本発明の範囲外の比較例で
ある No.１４〜１８では、Ａｌ含有率９０％未満のもの
や膜厚が１０ｎｍ〜２００ｎｍの範囲にならないものが
あり、鋼管の位置によってＡｌ含有量や膜厚が異なって
いた。 No.１９で生成したＡｌ酸化物皮膜は、Ａｌ含有
率が低く膜厚も不足していた。さらに No.１４〜１８で
は、オゾン含有水中での金属溶出量が多く、耐オゾン含
有水性は不芳であった。On the other hand, water vapor content, hydrogen content,
In Nos. 14 to 18, which are comparative examples in which any one of the heating temperatures of the steel pipe is out of the range of the present invention, there is a steel pipe having an Al content of less than 90% and a film thickness not falling within the range of 10 nm to 200 nm. The Al content and the film thickness differed depending on the position. The Al oxide film produced in No. 19 had a low Al content and an insufficient film thickness. Further, in Nos. 14 to 18, the metal elution amount in the ozone-containing water was large, and the ozone-containing water resistance was poor.
【００６８】[0068]
【発明の効果】本発明の酸化処理方法によれば、半導体
や医薬品、食品の製造に使用されるオゾン含有水等の流
体を搬送するために使用するステンレス鋼管の内面に、
能率良くしかもＡｌ含有量と膜厚が均一なＡｌ酸化物皮
膜を形成することができる。According to the oxidation treatment method of the present invention, the inner surface of a stainless steel pipe used for transporting a fluid such as ozone-containing water used in the production of semiconductors, pharmaceuticals, and foods,
An Al oxide film having high efficiency and a uniform Al content and thickness can be formed.
【図１】本発明の酸化処理方法を実施するのに用いる酸
化処理装置の１例を示す概略断面図である。FIG. 1 is a schematic sectional view showing an example of an oxidation treatment apparatus used to carry out an oxidation treatment method of the present invention.
【図２】本発明の酸化処理方法を実施するのに用いる酸
化処理装置の他の例を示す概略断面図である。FIG. 2 is a schematic sectional view showing another example of an oxidation treatment apparatus used to carry out the oxidation treatment method of the present invention.
１ａ、１ｂ ステンレス鋼管 ２ 酸化性ガス ３ チャンバ ４ 非酸化雰囲気 ５ 加熱炉 ６ オリフィス ７ａ、７ｂ 非酸化雰囲気供給、排出口 ９ 管継ぎ手 10 マッフル 1a, 1b Stainless steel pipe 2 Oxidizing gas 3 Chamber 4 Non-oxidizing atmosphere 5 Heating furnace 6 Orifice 7a, 7b Non-oxidizing atmosphere supply / discharge port 9 Pipe joint 10 Muffle
Claims (5)
気：０．５〜３０体積ｐｐｍを含み、残部が不活性ガス
からなる酸化性混合ガスを、重量％でＡｌを１〜６％含
有するステンレス鋼管内に流しつつ、加熱炉内に前記ス
テンレス鋼管を挿入し、その長手方向に移動させながら
８００〜１２００℃に加熱して、ステンレス鋼管の内面
にＡｌ酸化物被膜を形成させることを特徴とするステン
レス鋼管内面の酸化処理方法。1. An oxidizing mixed gas containing 10 to 99.9999% by volume of hydrogen and 0.5 to 30% by volume of water vapor and the balance being an inert gas, and containing 1 to 6% by weight of Al. The stainless steel pipe is inserted into a heating furnace while flowing in the stainless steel pipe to be heated, and heated to 800 to 1200 ° C. while moving in the longitudinal direction to form an Al oxide film on the inner surface of the stainless steel pipe. Oxidation treatment method for the inner surface of a stainless steel pipe.
炉出口近傍においてステンレス鋼管の外面が酸化しない
ように、ステンレス鋼管のパスライン周辺を非酸化性雰
囲気とする請求項１記載のステンレス鋼管内面の酸化処
理方法。2. The stainless steel pipe according to claim 1, wherein the stainless steel pipe is provided with a non-oxidizing atmosphere around the pass line so that the outer surface of the stainless steel pipe is not oxidized near the entrance of the heating furnace, in the heating furnace, and near the heating furnace outlet. Inner surface oxidation treatment method.
けることによりステンレス鋼管のパスライン周辺を非酸
化性雰囲気とする請求項２記載のステンレス鋼管内面の
酸化処理方法。3. The method for oxidizing the inner surface of a stainless steel pipe according to claim 2, wherein a heating furnace is provided in a chamber in a non-oxidizing atmosphere to make the periphery of the pass line of the stainless steel pipe a non-oxidizing atmosphere.
を用い、マッフル内を非酸化性雰囲気とすることによ
り、テンレス鋼管のパスライン周辺を非酸化性雰囲気と
する請求項２記載のステンレス鋼管内面の酸化処理方
法。4. The stainless steel according to claim 2, wherein a heating furnace having a muffle longer than the heating furnace is used, and the inside of the muffle is made a non-oxidizing atmosphere, so that the periphery of the pass line of the stainless steel pipe is made a non-oxidizing atmosphere. Oxidation treatment method for steel pipe inner surface.
流量が下記式を満足する量である請求項１、２、３およ
び４記載のステンレス鋼管内面の酸化処理方法。 酸化性混合ガスの流量（リットル／分）≧８．２６×Ｒ×
（Ｌ／Ｔ）／Ｃ ここで、 Ｒ：ステンレス鋼管の内径（ｍｍ） Ｌ：加熱炉均熱帯長さ（ｃｍ） Ｔ：ステンレス鋼管の均熱帯での酸化処理時間（分） Ｃ：酸化性ガス中の水蒸気濃度（体積ｐｐｍ）5. The method for oxidizing the inner surface of a stainless steel pipe according to claim 1, wherein the flow rate of the oxidizing mixed gas flowing into the stainless steel pipe is an amount satisfying the following expression. Flow rate of oxidizing mixed gas (liter / min) ≧ 8.26 × R ×
(L / T) / C where: R: inner diameter of stainless steel pipe (mm) L: length of heating furnace soaking zone (cm) T: oxidation treatment time of stainless steel tube in soaking zone (min) C: oxidizing gas Water vapor concentration (ppm by volume)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31276898A JP3864585B2 (en) | 1998-11-04 | 1998-11-04 | Method of oxidizing the inner surface of stainless steel pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31276898A JP3864585B2 (en) | 1998-11-04 | 1998-11-04 | Method of oxidizing the inner surface of stainless steel pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000144369A true JP2000144369A (en) | 2000-05-26 |
| JP3864585B2 JP3864585B2 (en) | 2007-01-10 |
Family
ID=18033194
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31276898A Expired - Fee Related JP3864585B2 (en) | 1998-11-04 | 1998-11-04 | Method of oxidizing the inner surface of stainless steel pipe |
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| Country | Link |
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| JP (1) | JP3864585B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003239060A (en) * | 2002-02-13 | 2003-08-27 | Sumitomo Metal Ind Ltd | HEAT TREATMENT METHOD FOR Ni-BASE ALLOY TUBE |
| JP2010138473A (en) * | 2008-12-15 | 2010-06-24 | Sumitomo Metal Ind Ltd | Method for producing metal tube |
| JP2012018920A (en) * | 2010-06-11 | 2012-01-26 | Semiconductor Energy Lab Co Ltd | Ion doping apparatus and method of reducing dust in ion doping apparatus |
| CN103484829A (en) * | 2013-09-29 | 2014-01-01 | 西安超码科技有限公司 | Method and device for preparing film in tube through chemical vapor deposition |
| JP2020169346A (en) * | 2019-04-02 | 2020-10-15 | 日本製鉄株式会社 | Alloy pipe |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003239060A (en) * | 2002-02-13 | 2003-08-27 | Sumitomo Metal Ind Ltd | HEAT TREATMENT METHOD FOR Ni-BASE ALLOY TUBE |
| JP2010138473A (en) * | 2008-12-15 | 2010-06-24 | Sumitomo Metal Ind Ltd | Method for producing metal tube |
| JP2012018920A (en) * | 2010-06-11 | 2012-01-26 | Semiconductor Energy Lab Co Ltd | Ion doping apparatus and method of reducing dust in ion doping apparatus |
| CN103484829A (en) * | 2013-09-29 | 2014-01-01 | 西安超码科技有限公司 | Method and device for preparing film in tube through chemical vapor deposition |
| JP2020169346A (en) * | 2019-04-02 | 2020-10-15 | 日本製鉄株式会社 | Alloy pipe |
| JP7486925B2 (en) | 2019-04-02 | 2024-05-20 | 日本製鉄株式会社 | Alloy Tube |
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