JP3310797B2 - Gas nitrocarburizing method - Google Patents
Gas nitrocarburizing methodInfo
- Publication number
- JP3310797B2 JP3310797B2 JP31747094A JP31747094A JP3310797B2 JP 3310797 B2 JP3310797 B2 JP 3310797B2 JP 31747094 A JP31747094 A JP 31747094A JP 31747094 A JP31747094 A JP 31747094A JP 3310797 B2 JP3310797 B2 JP 3310797B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- pressure
- chamber
- nitrocarburizing
- valve
- 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 - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 35
- 239000007789 gas Substances 0.000 claims description 34
- 238000012545 processing Methods 0.000 claims description 34
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 28
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 12
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- 239000011261 inert gas Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000001273 butane Substances 0.000 claims description 5
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 claims description 5
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 claims description 5
- 239000001294 propane Substances 0.000 claims description 5
- 239000000567 combustion gas Substances 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000005121 nitriding Methods 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- 210000002159 anterior chamber Anatomy 0.000 claims description 2
- 238000004880 explosion Methods 0.000 description 8
- 239000010410 layer Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000012495 reaction gas Substances 0.000 description 4
- 239000012159 carrier gas Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000007542 hardness measurement Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は鋼の軟窒化方法に関する
ものである。軟窒化は、鋼の表面から内部に向かって窒
素原子と炭素原子を浸透・拡散させて固溶させ、表面近
傍に両者の化合物を析出させることにより、被処理材の
耐摩耗性、疲労強度、耐食性等を著しく向上させること
ができる表面硬化法で、他の表面硬化法、例えば浸炭焼
入れと比較して寸法変化が非常に少ないという特徴を有
する。そのため、主として小物機械部品の表面硬化処理
に広く用いられている。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for soft nitriding steel. In soft nitriding, the nitrogen and carbon atoms penetrate and diffuse from the surface of the steel toward the inside to form a solid solution, and both compounds are deposited near the surface, resulting in wear resistance, fatigue strength, This is a surface hardening method that can significantly improve corrosion resistance and the like, and has a feature that dimensional change is very small as compared with other surface hardening methods, for example, carburizing and quenching. Therefore, it is widely used mainly for surface hardening treatment of small mechanical parts.
【０００２】[0002]
【従来の技術】ところで、ガスによる軟窒化方法とし
て、従来よりアンモニアガスと吸熱型変成ガス（以下Ｒ
Ｘガスという）による方法があり、また最近では窒素ガ
スにアンモニアガスとＣＯ２ガスを添加する方法などが
知られている。2. Description of the Related Art Conventionally, as a method of nitrocarburizing with a gas, an ammonia gas and an endothermic modified gas (hereinafter referred to as R) have been used.
X gas), and recently, a method of adding ammonia gas and CO 2 gas to nitrogen gas is known.
【０００３】[0003]
【発明が解決しようとする課題】アンモニアガスとＲＸ
ガスによる方法の場合、吸熱型変成炉が別途必要であ
る、多量のアンモニアガスを消費する、スーティングを
起こしやすい等の問題があった。また、窒素ガスにアン
モニアガスとＣＯ２ガスを添加する方法の場合、高価な
市販窒素ガスを使用する、あるいは窒素ガス発生装置が
別途必要である、などの問題がある。SUMMARY OF THE INVENTION Ammonia gas and RX
In the case of the method using gas, there are problems that an endothermic shift furnace is separately required, a large amount of ammonia gas is consumed, and sooting is easily caused. Further, in the case of adding ammonia gas and CO 2 gas to nitrogen gas, there is a problem that an expensive commercially available nitrogen gas is used or a nitrogen gas generator is separately required.
【０００４】そこで本発明は、変成炉や窒素ガス発生装
置を必要とせず、高価な窒素ガスを使用せず、また少な
いガス流量で安価で且つ安全に行うことができる軟窒化
処理方法を提供することを目的としてなされたものであ
る。Accordingly, the present invention provides a nitrocarburizing method which does not require a shift furnace or a nitrogen gas generator, does not use expensive nitrogen gas, and can be performed cheaply and safely with a small gas flow rate. It is done for the purpose of.
【０００５】[0005]
【課題を解決するための手段】本発明は、予め概ね５７
０℃に加熱保持された処理室に被処理物を装入して、鋼
部品の表面に窒素と炭素の化合物層を形成する軟窒化処
理法において、該処理室に実質的にアンモニアガスとＣ
Ｏ２ガスのみを導入して処理雰囲気を調製することを特
徴とするものである。また本発明は、処理室と前室とを
有する熱処理炉による、上記のガス軟窒化処理法におい
て、該両室間の被処理品の出し入れを減圧下で、または
不活性ガスを導入して大気圧以上の圧力下で行うことを
特徴とするものである。また本発明は、処理室と前室と
を有する熱処理炉による、該上記のガス軟窒化処理法に
おいて、該両室間の被処理品の出し入れの際に前室の圧
力を検出し、該圧力が負圧となったときに前室に窒素ガ
ス、ブタンまたはプロパンの少なくとも一つから選ばれ
たガスの燃焼ガスを吸引させることを特徴とするもので
ある。According to the present invention, there is provided an information processing apparatus comprising:
In a nitrocarburizing treatment method in which an object to be treated is charged into a treatment chamber heated and maintained at 0 ° C. and a compound layer of nitrogen and carbon is formed on the surface of a steel part, ammonia gas and C
The process atmosphere is prepared by introducing only O 2 gas. Further, according to the present invention, in the above-mentioned gas nitrocarburizing method using a heat treatment furnace having a processing chamber and a pre-chamber, the loading and unloading of an article to be processed between the two chambers can be performed under reduced pressure or by introducing an inert gas. The process is performed under a pressure higher than the atmospheric pressure. Further, according to the present invention, in the above-described gas nitrocarburizing method using a heat treatment furnace having a processing chamber and a front chamber, the pressure of the front chamber is detected when the article to be processed is taken in and out between the two chambers. When the pressure becomes negative, combustion gas of at least one of nitrogen gas, butane and propane is sucked into the front chamber.
【０００６】[0006]
【作用】処理室内では以下の反応が起こる。 ２ＮＨ３→ ２〔Ｎ〕 ＋ ３Ｈ２ ・・・・・ （１） ＣＯ２ ＋ Ｈ２ → ＣＯ ＋ Ｈ２Ｏ ・・・・・ （２） ２ＣＯ → 〔Ｃ〕 ＋ ＣＯ２ ・・・・・ （３） 以上の反応により発生した発生期のＮとＣが鋼の表面よ
り侵入して内向きに拡散し、固溶する。また表面近傍に
化合物を析出して、拡散層と析出化合物とからなる表面
硬化層をつくる。The following reactions occur in the processing chamber. 2NH 3 → 2 [N] + 3H 2 ··· (1) CO 2 + H 2 → CO + H 2 O · · · (2) 2CO → [C] + CO 2 ···· (3) The nascent N and C generated by the above reaction penetrate from the surface of the steel, diffuse inward, and form a solid solution. Further, a compound is deposited near the surface to form a hardened surface layer composed of the diffusion layer and the precipitated compound.
【０００７】キャリアガスを用いず、アンモニアガスと
ＣＯ２ガス、即ち反応ガスのみが処理室内に導入される
ので、反応ガスが希釈されることなく、少ないガス流量
でも反応の進行に充分なガス分圧が達成される。Since only the ammonia gas and the CO 2 gas, ie, the reaction gas, are introduced into the processing chamber without using a carrier gas, the reaction gas is not diluted, and a gas component sufficient for the reaction to proceed even at a small gas flow rate is used. Pressure is achieved.
【０００８】処理室と前室間の被処理品の出し入れを減
圧下で、または不活性ガスを導入して大気圧以上の圧力
下で行い、装置内の酸素濃度を爆発限界以下に抑える。
また、処理室と前室間の被処理品の出し入れの際に、前
室が負圧となったときに前室にブタンまたはプロパンの
燃焼ガスを吸引させる場合は、これらの原料ガス投入量
１体積あたり、燃焼生成物として２０〜２６体積程度の
窒素ガスを含む大量の雰囲気が入手でき、安価である。
こうして、前室が負圧となったときに単に窒素ガスを吸
引させる場合と同様、爆発を防止できる。The loading and unloading of articles to be processed between the processing chamber and the prechamber is performed under reduced pressure or at a pressure higher than the atmospheric pressure by introducing an inert gas, so that the oxygen concentration in the apparatus is kept below the explosion limit.
In addition, when injecting or removing an article to be processed between the processing chamber and the front chamber, when the combustion pressure of butane or propane is sucked into the front chamber when the front chamber becomes a negative pressure, the raw material gas input amount is set to 1 A large amount of atmosphere containing about 20 to 26 volumes of nitrogen gas as a combustion product per volume is available and inexpensive.
Thus, an explosion can be prevented as in the case of simply sucking nitrogen gas when the pressure in the front chamber becomes negative.
【０００９】[0009]
【実施例】次に、本発明の実施例を図面を参照しながら
説明する。Next, embodiments of the present invention will be described with reference to the drawings.
【００１０】[0010]
【実施例１】図１は、本発明の方法の実施に使用できる
装置の１構成例を示すもので、処理室（１）と前室
（２）の両方が真空排気可能となっている。処理室
（１）の容積は１．０３ｍ３である。まず弁（７）を開
き処理室（１）を真空ポンプ（４）で排気しながら、処
理室（１）を５７０℃まで昇温する。復温完了後、弁
（１２）を開いて処理室（１）に窒素ガスを供給し、復
圧する。復圧後は弁（１２）を閉じて窒素ガスの供給を
止めたあと、弁（１３）を開き、アンモニアガスを１．
５ｍ３／ｈｒ、ＣＯ２ガスを０．２ｍ３／ｈｒの流量で
供給して、処理雰囲気を調製する。[Embodiment 1] FIG. 1 shows an example of the structure of an apparatus which can be used for carrying out the method of the present invention. Both the processing chamber (1) and the front chamber (2) can be evacuated. The volume of the processing chamber (1) is 1.03 m 3 . First, the temperature of the processing chamber (1) is raised to 570 ° C. while opening the valve (7) and evacuating the processing chamber (1) by the vacuum pump (4). After the completion of the temperature recovery, the valve (12) is opened and nitrogen gas is supplied to the processing chamber (1) to recover the pressure. After the pressure is restored, the valve (12) is closed to stop the supply of the nitrogen gas.
The processing atmosphere is prepared by supplying 5 m 3 / hr and CO 2 gas at a flow rate of 0.2 m 3 / hr.
【００１０】ここで処理室（１）内の圧力が大気圧以上
のときは弁（７）と弁（１９）を開いて排気し、また処
理室（１）内の圧力が大気圧より低いときには弁（１
９）が自動的に閉じるようになっている。処理室からの
排気配管の温度が低いとＮＨ４（ＣＯ３）２の粉が発生
し、配管の詰まりを生ずるので、排気配管は１５０℃に
加熱・保温されている。真空ポンプとしては、通常のロ
ータリーポンプを使用すると真空ポンプ油に未分解のア
ンモニアが溶け込み、その後徐々にいつまでも蒸発を続
けて可燃性ガスを排出することになるので安全上好まし
くない。そこで油や水を使わないドライポンプを使用し
ている。Here, when the pressure in the processing chamber (1) is higher than the atmospheric pressure, the valve (7) and the valve (19) are opened to evacuate, and when the pressure in the processing chamber (1) is lower than the atmospheric pressure. Valve (1
9) automatically closes. If the temperature of the exhaust pipe from the processing chamber is low, powder of NH 4 (CO 3 ) 2 is generated and the pipe is clogged. Therefore, the exhaust pipe is heated and kept at 150 ° C. If a normal rotary pump is used as the vacuum pump, undecomposed ammonia dissolves in the vacuum pump oil, and thereafter, it evaporates forever and flammable gas is discharged, which is not preferable in terms of safety. Therefore, a dry pump that does not use oil or water is used.
【００１２】処理室（１）内の雰囲気が安定した後、被
処理品（１０）を搬入するが、それには、次のようにす
る。まず前扉（１４）を開き、被処理品（１０）を、油
槽上部の前室（２）内に装入する。弁（５）を開き、真
空ポンプ（３）により前室（２）を真空排気する。前室
（２）内の圧力が１０Ｔｏｒｒ以下になったところで弁
（５）を閉じ、続いて同圧弁（１７）を開く。処理室
（１）と前室（２）とが同圧となったところで中間扉
（１５）を開き、被処理品（１０）を処理室（１）内に
搬送する。次に中間扉（１５）と同圧弁（１７）を閉じ
て、所定時間の処理を行う。After the atmosphere in the processing chamber (1) is stabilized, the article to be processed (10) is carried in, as follows. First, the front door (14) is opened, and the article to be processed (10) is loaded into the front chamber (2) above the oil tank. The valve (5) is opened, and the front chamber (2) is evacuated by the vacuum pump (3). When the pressure in the front chamber (2) becomes 10 Torr or less, the valve (5) is closed, and then the same pressure valve (17) is opened. When the processing chamber (1) and the front chamber (2) have the same pressure, the intermediate door (15) is opened, and the article to be processed (10) is transported into the processing chamber (1). Next, the intermediate door (15) and the same pressure valve (17) are closed, and a process for a predetermined time is performed.
【００１３】所定時間経過後、同圧弁（１７）を開き、
前室（２）と処理室（１）とを同圧にする。次に弁
（６）を開き、前室（２）内が所定圧力になるまで窒素
ガスを供給する。弁（１３）を閉じる。中間扉（１５）
を開き、被処理品（１０）を前室（２）へ搬送する。中
間扉（１５）を閉じると同時に被処理品（１０）をエレ
ベータで油槽の焼入油中につけて油冷する。同圧弁（１
５）を閉じる。弁（１３）を開きガスを流す。弁（５）
を開き前室（２）を真空ポンプ（３）により真空排気す
る。所定時間の油冷の後、被処理品（１０）を焼入油中
から引き上げ、油切りを行う。所定時間の油切りの後、
弁（５）を閉じたあと弁（６）を開き、前室（２）を窒
素ガスで大気圧まで復圧し、弁（６）を閉じると同時に
前扉（１４）を開き被処理品（１０）を搬出する。前扉
（１４）を閉じる。After a lapse of a predetermined time, the same-pressure valve (17) is opened,
The front chamber (2) and the processing chamber (1) are set to the same pressure. Next, the valve (6) is opened, and nitrogen gas is supplied until the inside of the front chamber (2) reaches a predetermined pressure. Close valve (13). Intermediate door (15)
Is opened, and the article to be processed (10) is transported to the front chamber (2). At the same time as closing the intermediate door (15), the article to be treated (10) is immersed in quenched oil in an oil tank by an elevator and oil-cooled. Same pressure valve (1
5) Close. Open valve (13) and allow gas to flow. Valve (5)
Is opened, and the front chamber (2) is evacuated by a vacuum pump (3). After oil cooling for a predetermined time, the article to be treated (10) is pulled out of the quenched oil, and oil is removed. After a predetermined amount of oil draining,
After closing the valve (5), the valve (6) is opened, the pressure in the front chamber (2) is restored to the atmospheric pressure with nitrogen gas, and the front door (14) is opened at the same time as the valve (6) is closed to open the article (10). ). Close the front door (14).
【００１４】[0014]
【実施例２】本発明はまた、図２に示すような、前室
（２）のみ真空排気可能な装置を使用して実施すること
もできる。処理室（１）は通常の雰囲気熱処理炉と同様
のものである。この場合、先に述べた実施例１の装置を
使用して本発明を実施する場合と比べて、次の点が異な
る。即ち、１）処理室内（１）における雰囲気の調製方
法、および、２）処理室（１）と前室（２）との間の被
処理品（１０）の出し入れの際の圧力制御方法、の二点
が異なる。以下順にそれを説明する。[Embodiment 2] The present invention can also be carried out by using a device capable of evacuating only the front chamber (2) as shown in FIG. The processing chamber (1) is similar to a normal atmosphere heat treatment furnace. In this case, the following points are different from the case where the present invention is implemented using the apparatus of the first embodiment described above. That is, 1) a method of preparing an atmosphere in the processing chamber (1), and 2) a method of controlling a pressure when the article to be processed (10) is taken in and out between the processing chamber (1) and the front chamber (2). Two differences. These will be described below in order.
【００１５】１）まず弁（７）を開き、処理室（１）の
温度を５７０℃まで昇温する。昇温開始と同時に弁（１
２）を開き、窒素ガスを流す。昇温が完了し、且つ処理
室（１）内の残存空気濃度が爆発限界以下まで窒素ガス
でパージされた時点で、弁（１３）を開き、アンモニア
ガスとＣＯ２ガスを流す。ガスが流れていることを流量
計（８）、（９）で確認した後、弁（１２）を閉じて窒
素ガスを止める。1) First, the valve (7) is opened, and the temperature of the processing chamber (1) is raised to 570 ° C. The valve (1
Open 2) and let nitrogen gas flow. When the temperature rise has been completed and the residual air concentration in the processing chamber (1) has been purged with nitrogen gas to below the explosion limit, the valve (13) is opened, and ammonia gas and CO 2 gas flow. After confirming that the gas is flowing with the flow meters (8) and (9), the valve (12) is closed to stop the nitrogen gas.
【００１６】２）処理室（１）と前室（２）の間の被処
理品（１０）の出し入れの際には、まず弁（６）を開い
て前室（２）に窒素ガスを供給し、前室（２）内の圧力
が大気圧以上になるまで復圧してから、同圧弁（１７）
を開く。そのあとで中間扉（１５）を開いて被処理品
（１０）の搬送を行う。2) When the article to be processed (10) is taken in and out between the processing chamber (1) and the front chamber (2), the valve (6) is first opened to supply nitrogen gas to the front chamber (2). Then, the pressure in the front chamber (2) is restored until the pressure in the front chamber (2) becomes higher than the atmospheric pressure.
open. After that, the intermediate door (15) is opened to carry the article to be processed (10).
【００１７】[0017]
【実施例３】本発明はまた、真空排気を全く使用せず
に、図３に示すような、通常の雰囲気熱処理炉と同様の
装置を使用しても実施することができる。その場合、処
理室（１）に導入された雰囲気ガスは、中間扉（１５）
の小孔や周囲から漏れ出して前室（２）に流れてゆき、
前室（２）内の雰囲気ガスは排ガスベントを通って炉外
に排出される。被処理品（１０）搬送時の炉の動作は大
略通常のガス軟窒化炉と同様であるが、通常のガス軟窒
素化炉に比べてガス流量がかなり少ないために、特に爆
発防止対策が必要である。[Embodiment 3] The present invention can also be carried out by using an apparatus similar to a normal atmospheric heat treatment furnace as shown in FIG. 3 without using any vacuum evacuation. In that case, the atmospheric gas introduced into the processing chamber (1) is supplied to the intermediate door (15).
Leaks out of the small holes and surroundings and flows into the anterior chamber (2),
The atmosphere gas in the front chamber (2) is discharged outside the furnace through the exhaust gas vent. The operation of the furnace at the time of transporting the article to be processed (10) is almost the same as that of a normal gas nitrocarburizing furnace, but the gas flow rate is considerably smaller than that of a normal gas nitrocarburizing furnace. It is.
【００１８】爆発を防止するためには前室の空間容積を
できるだけ小さくし、装置内負圧時間を出来るだけ短く
することが必要である。しかし、それだけでは確実に爆
発を防止することはできない。確実に防止するために
は、油冷や、前扉が閉じたために装置内が負圧になった
とき、不活性ガスを強制的に装置内に吸引させることに
より、装置内への外気の吸引を阻止する必要がある。不
活性ガスとしては窒素ガスが考えられるが、高価である
上に反応性ガスを希釈してしまうという問題がある。そ
こで強制吸引させるガスとして、不活性ガスのかわりに
ブタン、プロパン等の燃焼ガスを使用する。図３に示す
ように、装置内の圧力を常時圧力スイッチで監視し、負
圧になった際には爆発防止用バーナを自動的に燃焼させ
る。In order to prevent an explosion, it is necessary to make the space volume of the front chamber as small as possible and to make the negative pressure time in the apparatus as short as possible. However, this alone cannot reliably prevent an explosion. In order to prevent this, it is necessary to prevent the outside air from being sucked into the device by forcibly sucking inert gas into the device when the inside of the device becomes negative pressure due to oil cooling or when the front door is closed. It needs to be stopped. As an inert gas, a nitrogen gas is conceivable, but it is expensive and has a problem of diluting the reactive gas. Therefore, as the gas to be forcibly sucked, a combustion gas such as butane or propane is used instead of the inert gas. As shown in FIG. 3, the pressure in the apparatus is constantly monitored by a pressure switch, and when the pressure becomes negative, the burner for preventing explosion is automatically burned.
【００１９】次に、本発明の方法と従来法により、それ
ぞれ処理した部材の表面硬度、組織等につき調査し、品
質の比較を行った。テスト条件および結果を以下に示
す。被処理品としては、以下のものを用いた。 寸法：１２０ｍｍ×５０ｍｍ×２．３ｍｍ（厚み） 材質：ＳＰＣ材 重量：７２．６ｇ／個 処理条件としては、図４に示すものを用いた。被処理品
の表面硬度は、マイクロビッカース硬度計を用い、測定
荷重１００ｇで、１個当たり表と裏各３点ずつ測定し
た。その結果を表１に示す。参考値として、処理前の生
材の表面硬度はＨｖ（０．１）１１８であった。また表
面硬度測定結果の度数分布をとったところ、図５に示す
ようになった。Next, by using the method of the present invention and the conventional method, the surface hardness, the structure and the like of each treated member were investigated, and the quality was compared. The test conditions and results are shown below. The following were used as articles to be processed. Dimensions: 120 mm × 50 mm × 2.3 mm (thickness) Material: SPC material Weight: 72.6 g / piece The processing conditions shown in FIG. 4 were used. The surface hardness of the article to be treated was measured using a micro-Vickers hardness tester at a measurement load of 100 g and three points each for the front and back sides. Table 1 shows the results. As a reference value, the surface hardness of the raw material before the treatment was Hv (0.1) 118. FIG. 5 shows the frequency distribution of the surface hardness measurement results.
【００２０】[0020]
【表１】 [Table 1]
【００２１】次に被処理表面に垂直な、被処理表面近傍
の断面組織を光学顕微鏡で観察した。その結果を図６に
示す。両者ともほぼ同様の組織を呈する。次に、化合物
層の厚さを上記と同一の断面上で測定した。その結果を
表２に示す。Next, a cross-sectional structure perpendicular to the surface to be processed and near the surface to be processed was observed with an optical microscope. FIG. 6 shows the result. Both exhibit almost the same organization. Next, the thickness of the compound layer was measured on the same cross section as above. Table 2 shows the results.
【００２２】次に、化合物層の組成を同定するために、
Ｘ線回折分析を行った。その回折パターンを図７に示
す。両者ともＦｅ３Ｎのピークと同定されるが、本発明
の方法で処理したものの方が従来法で処理したものに比
べてわずかに広角側にずれており、少し格子面間隔が大
きくなっていることがわかった。Ｆｅ３Ｃのピークは両
者ともに検出されなかった。Next, in order to identify the composition of the compound layer,
X-ray diffraction analysis was performed. FIG. 7 shows the diffraction pattern. Both of them are identified as Fe 3 N peaks, but those processed by the method of the present invention are slightly shifted to the wide-angle side as compared with those processed by the conventional method, and the lattice spacing is slightly larger. I understand. No Fe 3 C peak was detected in either case.
【００２３】以上により、本発明の方法によれば、キャ
リアガスを使用せず、且つより少ない反応ガス流量で、
従来技術の方法とほぼ同等品質の軟窒化処理品が得られ
ることが確認できた。As described above, according to the method of the present invention, a carrier gas is not used, and a smaller reaction gas flow rate is used.
It was confirmed that a nitrocarburized product having almost the same quality as that of the method of the prior art can be obtained.
【００２４】[0024]
【表２】 [Table 2]
【００２５】次に、本発明の方法と従来法における使用
ガスのコストを比較した。金額計算に際し、各ガスの立
方メートル当たりの単価をそれぞれ、ＮＨ３＝３４２，
ＲＸ＝１９，ＣＯ２＝１５７，Ｎ２＝７０とし、また処
理室の容積を２．１ｍ３とした。その結果を表３に示
す。以上のように、本発明の方法は、従来技術の方法に
比べてガスのコストが大幅に少なくて済む。Next, the costs of gases used in the method of the present invention and the conventional method were compared. In calculating the amount of money, the unit price per cubic meter of each gas was NH 3 = 342,
RX = 19, CO 2 = 157, N 2 = 70, and the volume of the processing chamber was 2.1 m 3 . Table 3 shows the results. As described above, the method of the present invention requires much less gas cost than the prior art method.
【００２６】[0026]
【表３】 [Table 3]
【００２７】[0027]
【発明の効果】本発明の方法によれば、吸熱型変成炉や
窒素ガス発生装置などのキャリアガス発生装置を必要と
せず、また高価なアンモニアガスや市販窒素ガスを多量
に使用することもないため、従来に比べてより安価に軟
窒化処理を行うことができる。また本発明の方法によれ
ば、処理室と前室間の被処理品の出し入れを減圧下で、
または不活性ガスを導入して大気圧以上の圧力下で行う
ので、少ない反応ガス流量でも爆発の危険がなく、安全
に軟窒化処理を行うことができる。同様に、出し入れの
際、前室が負圧となったときに、前室にブタンまたはプ
ロパンの燃焼ガスを吸引させることにすれば、パージガ
スのコストを削減でき、処理コストを一層下げることが
できると同時に、単に窒素ガスを吸引させる場合同様、
爆発の危険をなくすことができる。According to the method of the present invention, a carrier gas generator such as an endothermic shift furnace or a nitrogen gas generator is not required, and a large amount of expensive ammonia gas or commercially available nitrogen gas is not used. Therefore, the nitrocarburizing treatment can be performed at lower cost than in the conventional case. Further, according to the method of the present invention, the removal of the article to be processed between the processing chamber and the front chamber is performed under reduced pressure,
Alternatively, since the reaction is performed under a pressure higher than the atmospheric pressure by introducing an inert gas, there is no danger of explosion even with a small flow rate of the reaction gas, and the nitrocarburizing treatment can be performed safely. Similarly, when the front chamber is at a negative pressure when taking in and out, if the combustion gas of butane or propane is sucked into the front chamber, the cost of the purge gas can be reduced, and the processing cost can be further reduced. At the same time, just like letting nitrogen gas suck,
Explosion danger can be eliminated.
【００２８】[0028]
【図１】は本発明の方法の実施に使用する装置の一態様
を示す図である。FIG. 1 is a diagram showing one embodiment of an apparatus used for carrying out the method of the present invention.
【図２】は本発明の方法の実施に使用する装置の他の一
態様を示す図である。FIG. 2 is a diagram showing another embodiment of an apparatus used for carrying out the method of the present invention.
【図３】は本発明の方法の実施に使用する装置のさらに
他の一態様を示す図である。FIG. 3 is a diagram showing still another embodiment of the apparatus used for carrying out the method of the present invention.
【図４】は上記比較テストの処理条件を示す図である。FIG. 4 is a diagram showing processing conditions of the comparison test.
【図５】は上記比較テストにより得られた被処理品の表
面硬度測定結果のヒストグラムである。FIG. 5 is a histogram of a surface hardness measurement result of the article to be processed obtained by the above-described comparative test.
【図６】は上記比較テストにより得られた被処理品表面
近傍の、光学顕微鏡による断面組織写真である。FIG. 6 is a cross-sectional structure photograph by an optical microscope of the vicinity of the surface of the article to be processed obtained by the above-described comparative test.
【図７】は上記比較テストにより被処理品表面に形成さ
れた化合物層の、Ｘ線回折パターンである。FIG. 7 is an X-ray diffraction pattern of a compound layer formed on the surface of the article to be processed by the above-described comparative test.
１ 処理室 ２ 前室 ３ 真空ポンプ ４ 真空ポンプ ５ 真空弁 ６ 弁 ７ 真空弁 ８ 流量計 ９ 流量計 １０ 被処理品 １１ 雰囲気攪拌ファン １２ 弁 １３ 弁 １４ 前扉 １５ 中間扉 １６ シーケンサ １７ 同圧弁 １８ 弁 １９ 弁 DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Front chamber 3 Vacuum pump 4 Vacuum pump 5 Vacuum valve 6 Valve 7 Vacuum valve 8 Flowmeter 9 Flowmeter 10 Workpiece 11 Atmospheric stirring fan 12 Valve 13 Valve 14 Front door 15 Intermediate door 16 Sequencer 17 Same pressure valve 18 Valve 19 Valve
Claims (3)
室に被処理物を装入して、鋼部品の表面に窒素と炭素の
化合物層を形成する軟窒化処理法において、該処理室に
実質的にアンモニアガスとＣＯ２ガスのみを導入して処
理雰囲気を調製することを特徴とする鋼部品の軟窒化処
理方法。1. A nitrocarburizing treatment method in which an object to be processed is charged into a processing chamber heated and maintained at about 570 ° C. in advance and a compound layer of nitrogen and carbon is formed on the surface of a steel part. A method for nitrocarburizing steel parts, wherein a treatment atmosphere is prepared by introducing substantially only ammonia gas and CO 2 gas.
ガス軟窒化処理において、該両室間の被処理品の出し入
れを減圧下で、または不活性ガスを導入して大気圧以上
の圧力下で行うことを特徴とする、請求項１記載の鋼部
品の軟窒化処理方法。2. In a gas nitrocarburizing treatment by a heat treatment furnace having a treatment chamber and a front chamber, a product to be treated is taken in and out between the two chambers under reduced pressure or a pressure higher than the atmospheric pressure by introducing an inert gas. The method for nitrocarburizing a steel part according to claim 1, wherein the method is performed under the following conditions.
ガス軟窒化処理において、該両室間の被処理品の出し入
れの際に前室の圧力を検出し、該圧力が負圧となったと
きに前室に窒素ガス、ブタンまたはプロパンの少なくと
も一つから選ばれたガスの燃焼ガスを吸引させることを
特徴とする、請求項１記載の鋼部品の軟窒化処理方法。3. A gas nitrocarburizing process using a heat treatment furnace having a processing chamber and a front chamber, wherein the pressure of the front chamber is detected when a product to be processed is taken in and out between the two chambers, and the pressure becomes negative. 2. The method for soft-nitriding a steel part according to claim 1, wherein the combustion gas of at least one selected from the group consisting of nitrogen gas, butane and propane is sucked into the anterior chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31747094A JP3310797B2 (en) | 1994-11-14 | 1994-11-14 | Gas nitrocarburizing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31747094A JP3310797B2 (en) | 1994-11-14 | 1994-11-14 | Gas nitrocarburizing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08134626A JPH08134626A (en) | 1996-05-28 |
| JP3310797B2 true JP3310797B2 (en) | 2002-08-05 |
Family
ID=18088597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31747094A Expired - Lifetime JP3310797B2 (en) | 1994-11-14 | 1994-11-14 | Gas nitrocarburizing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3310797B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9212416B2 (en) | 2009-08-07 | 2015-12-15 | Swagelok Company | Low temperature carburization under soft vacuum |
| US10246766B2 (en) | 2012-01-20 | 2019-04-02 | Swagelok Company | Concurrent flow of activating gas in low temperature carburization |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4499886B2 (en) * | 2000-08-01 | 2010-07-07 | 中外炉工業株式会社 | Two-chamber gas nitronitriding furnace |
| JP5291354B2 (en) * | 2008-02-08 | 2013-09-18 | オリエンタルエンヂニアリング株式会社 | Gas nitriding furnace and gas soft nitriding furnace |
| JP5562726B2 (en) * | 2010-05-31 | 2014-07-30 | 一般財団法人電力中央研究所 | Curing detection method and curing detection system |
-
1994
- 1994-11-14 JP JP31747094A patent/JP3310797B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9212416B2 (en) | 2009-08-07 | 2015-12-15 | Swagelok Company | Low temperature carburization under soft vacuum |
| US10156006B2 (en) | 2009-08-07 | 2018-12-18 | Swagelok Company | Low temperature carburization under soft vacuum |
| US10934611B2 (en) | 2009-08-07 | 2021-03-02 | Swagelok Company | Low temperature carburization under soft vacuum |
| US10246766B2 (en) | 2012-01-20 | 2019-04-02 | Swagelok Company | Concurrent flow of activating gas in low temperature carburization |
| US11035032B2 (en) | 2012-01-20 | 2021-06-15 | Swagelok Company | Concurrent flow of activating gas in low temperature carburization |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08134626A (en) | 1996-05-28 |
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