JPS6341982B2 - - Google Patents
Info
- Publication number
- JPS6341982B2 JPS6341982B2 JP54041456A JP4145679A JPS6341982B2 JP S6341982 B2 JPS6341982 B2 JP S6341982B2 JP 54041456 A JP54041456 A JP 54041456A JP 4145679 A JP4145679 A JP 4145679A JP S6341982 B2 JPS6341982 B2 JP S6341982B2
- Authority
- JP
- Japan
- Prior art keywords
- cast iron
- soft
- nitriding
- oxide film
- iron material
- 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
Links
- 238000005121 nitriding Methods 0.000 claims description 35
- 229910001018 Cast iron Inorganic materials 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 25
- 238000004140 cleaning Methods 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 17
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 11
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 8
- 239000000839 emulsion Substances 0.000 claims description 7
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 7
- 239000002480 mineral oil Substances 0.000 claims description 7
- 235000010446 mineral oil Nutrition 0.000 claims description 7
- 238000005260 corrosion Methods 0.000 claims 1
- 239000007789 gas Substances 0.000 description 10
- 239000000243 solution Substances 0.000 description 9
- 238000012360 testing method Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 229910001562 pearlite Inorganic materials 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 1
- 239000010428 baryte Substances 0.000 description 1
- 229910052601 baryte Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 150000002505 iron Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/34—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases more than one element being applied in more than one step
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Description
【発明の詳細な説明】
この発明は鋳鉄材の軟窒化法に関し、詳しくは
軟窒化処理の前に鋳鉄材を予備酸化し、軟窒化処
理により形成する窒化層の成長速度を迅速にして
窒化層の厚さを厚くするようにしたものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soft nitriding method for cast iron materials, and more specifically, the cast iron material is pre-oxidized before soft nitriding treatment, and the growth rate of the nitrided layer formed by the soft nitriding treatment is increased to increase the nitrided layer. The thickness is increased.
ロータリエンジンのサイドハウジング等に用い
られる耐摩性が要求される鋳鉄では、軟窒化処理
を行い、表面に軟窒化層を形成することが行われ
ている。 Cast iron, which is used for side housings of rotary engines and the like and is required to have wear resistance, is subjected to soft nitriding treatment to form a soft nitrided layer on its surface.
従来、上記軟窒化処理は素材の表面を洗浄液で
洗浄して後に窒化炉に入れて行つているが、窒化
速度が遅く所要厚さの窒化層を得るのに長時間か
かり、多量生産に不適である欠点があつた。 Conventionally, the soft nitriding treatment described above is performed by cleaning the surface of the material with a cleaning solution and then putting it into a nitriding furnace, but the nitriding speed is slow and it takes a long time to obtain a nitrided layer of the required thickness, making it unsuitable for mass production. There was a certain drawback.
まして鋳鉄では基地がパーライトになつており
（摺動面等の耐摩耗性を要する部位では特に）、こ
のパーライト基地上には軟窒化層が形成しにく
く、一般に鋳鉄材表面に軟窒化層を工業的、量産
的に形成することはできないと考えられていた。 Furthermore, the base of cast iron is pearlite (especially in areas that require wear resistance such as sliding surfaces), and it is difficult to form a soft nitrided layer on this pearlite base, so it is generally difficult to form a soft nitrided layer on the surface of cast iron. It was thought that it could not be produced in a mass-produced manner.
本発明者達は上記欠点を解消するために種々の
実験を行つたところ、鋳鉄材を防錆洗浄液で洗浄
後、窒化炉に入れる前に鋳鉄材を加熱して表面に
Fe2O3を主成分とする酸化被膜を形成すると同時
に、その基地表面のパーライトをフエライト化し
ておくことにより、その後、窒化炉に入れると窒
化速度が速くなり、従来と同じ窒化炉で同一時間
窒化した場合、かなり厚い（約30％程度厚い）窒
化層が得られることを知見した。 The inventors of the present invention conducted various experiments to solve the above-mentioned drawbacks, and found that after cleaning the cast iron material with an anti-rust cleaning solution, the cast iron material was heated to coat the surface before being put into the nitriding furnace.
By forming an oxide film whose main component is Fe 2 O 3 and at the same time converting the pearlite on the surface of the base into ferrite, the nitriding speed becomes faster when placed in a nitriding furnace. It has been found that when nitrided, a considerably thick (approximately 30% thicker) nitrided layer can be obtained.
この発明は上記結果に基いてなされたものであ
り、鋳鉄材の表面を、防錆洗浄液で洗浄した後
に、該鋳鉄材を400〜500℃に加熱して表面に鉄の
酸化被膜を形成すると共に、基地表面のバーライ
トを分解し、フエライト化しておき、かつ該加熱
処理前あるいは加熱処理中に該洗浄液を取り除
き、その後に該鋳鉄材を軟窒化処理して表面に軟
窒化層を形成することを特徴とする鋳鉄材の軟窒
化法を提供せんとするものである。 This invention was made based on the above results, and after cleaning the surface of a cast iron material with an anti-rust cleaning solution, the cast iron material is heated to 400 to 500°C to form an iron oxide film on the surface. , Decompose the barite on the surface of the base to turn it into ferrite, and remove the cleaning liquid before or during the heat treatment, and then nitrocarburize the cast iron material to form a nitrocarburide layer on the surface. The present invention aims to provide a soft nitriding method for cast iron materials, which is characterized by the following.
さらに、この発明は、上記防錆洗浄液として鉱
油系エマルジヨンタイプのものを用い、予備酸化
加熱時に、上記洗浄液を燃焼して除去することも
できるようにしたものである。 Further, in the present invention, a mineral oil emulsion type cleaning liquid is used as the rust-preventing cleaning liquid, and the cleaning liquid can be burned and removed during preliminary oxidation heating.
以下に、この発明を詳述すると、まず、鋳鉄材
の表面を、パークレンやトリクレン等の洗浄液で
洗浄し、表面の防錆洗浄液を完全に取り除くか、
あるいは、防錆洗浄液として鉱油系エマルジヨン
タイプのものを用いる。該鉱油系エマルジヨンタ
イプのものを用いると次の加熱工程で完全に燃焼
させることができるので、パークレンやトリクレ
ン等で洗浄しなくてもよい。 The present invention will be described in detail below. First, the surface of the cast iron material is cleaned with a cleaning solution such as Perclean or Triclean, and the rust-preventing cleaning solution on the surface is completely removed.
Alternatively, a mineral oil emulsion type detergent may be used as the anti-rust cleaning solution. If the mineral oil emulsion type is used, it can be completely combusted in the next heating step, so there is no need to wash it with perclean, trichlene, or the like.
上記鋳鉄材の表面を洗浄後、該鋳鉄材を400℃
〜500℃で１〜２分間加熱し、鋳鉄材の表面に
Fe2O3を主成分とする鉄の酸化被膜を形成する。
この加熱時に、洗浄液として鉱油系エマルジヨン
タイプのものを用いた場合、酸化被膜形成前に洗
浄液は完全に燃焼し、除去される。 After cleaning the surface of the above cast iron material, heat the cast iron material to 400℃.
Heat at ~500℃ for 1 to 2 minutes and apply it to the surface of cast iron.
Forms an iron oxide film whose main component is Fe 2 O 3 .
When a mineral oil emulsion type cleaning liquid is used during this heating, the cleaning liquid is completely burned and removed before the oxide film is formed.
上記加熱温度を400℃〜500℃とするのは、400
℃未満ではパーライト基地のフエライト化がすみ
やかに行われず、また第２図の表にも示すように
酸化膜の形成も不十分となる。 The above heating temperature is 400°C to 500°C.
If the temperature is below .degree. C., the pearlite base will not be converted into ferrite quickly, and as shown in the table of FIG. 2, the formation of an oxide film will also be insufficient.
一方500℃を越えると鋳鉄表面の黒鉛組織と基
地との境界部で軟窒化層の形成能力の差が極端に
現われ、鋳鉄材の表面が荒れると共に、変形が生
ずる。この加熱処理は１〜２分で加熱を中止して
放冷してもよい。なお、長時間処理温度で保持す
ると酸化膜の膜厚や厚くなりすぎ表面に荒れ及び
変形が生ずるので好ましくない。なおこの時間
は、材料の成分や大きさにより適切な値を選定す
る。 On the other hand, when the temperature exceeds 500°C, there is an extreme difference in the ability to form a nitrocarburized layer at the boundary between the graphite structure on the surface of the cast iron and the matrix, causing the surface of the cast iron to become rough and deformed. This heat treatment may be stopped after 1 to 2 minutes and allowed to cool. It should be noted that holding the oxide film at the treatment temperature for a long time is not preferable because the oxide film becomes too thick and the surface becomes rough and deformed. Note that an appropriate value for this time is selected depending on the components and size of the material.
上記した酸化被膜を形成後、鋳鉄材をガス軟窒
化炉内に装入する。その際、上記加熱後に直ちに
炉に装入しても一度冷却してから炉内に装入して
も酸化膜による効果は同等である。ただ前者のほ
うが窒化前の加熱処理の効果が顕著になる点で有
利である。また、鉄の酸化膜を形成して窒化する
と窒化速度が速くなる理由としては次の点が考え
られる。ガス軟窒化炉内では、鉄の酸化物が再び
鉄と酸素とに分解されて新鮮な鉄ができ、新鮮な
鉄が準備されるため、炉内で、この鉄がＣやＮと
結合しやすい状態となつており、その結果、Fe
―Ｃ―Ｎ層（軟窒化層）が速く形成されることと
なるものと思われ、該軟窒化層の被形成性が向上
することになる。尚、軟窒化法は上記ガス軟窒化
法に限らず、塩溶窒化法で行つても同様の効果が
得られる。 After forming the above-described oxide film, the cast iron material is charged into a gas soft nitriding furnace. At this time, the effect of the oxide film is the same whether the material is charged into the furnace immediately after the heating or once cooled before being charged into the furnace. However, the former is advantageous in that the effect of the heat treatment before nitriding becomes more pronounced. Further, the reason why the nitriding rate increases when an iron oxide film is formed and nitrided is as follows. In the gas nitrocarburizing furnace, iron oxide is decomposed into iron and oxygen again to produce fresh iron, and as fresh iron is prepared, this iron easily combines with C and N in the furnace. As a result, Fe
It is thought that the -CN layer (soft nitrided layer) will be formed quickly, and the formation property of the soft nitrided layer will be improved. Note that the soft nitriding method is not limited to the above-mentioned gas soft nitriding method, but the same effect can be obtained even if a salt solution nitriding method is used.
（） 80mm×60mm×５mmのテストピースを鋳鉄
材FC30で鋳造し、該テストピースを鉱油系エ
マルジヨンタイプの防錆洗浄液で洗浄し、次
に、常温より500℃になる迄30分間加熱して酸
化被膜を形成し、500℃に上昇後直ちに常温ま
で放冷し、その後、ガス軟窒化炉（NH3ガ
ス：Rxガス＝60：40）で軟窒化処理した。こ
の軟窒化処理時間と形成される軟窒化層の厚さ
の相関関系は、第１図のａに示す通りである。
() A test piece measuring 80 mm x 60 mm x 5 mm was cast using cast iron material FC 30 , and the test piece was washed with a mineral oil-based emulsion type anti-rust cleaning solution, and then heated for 30 minutes from room temperature to 500°C. After raising the temperature to 500°C, it was immediately cooled to room temperature, and then subjected to soft nitriding treatment in a gas soft nitriding furnace (NH 3 gas:Rx gas = 60:40). The correlation between the soft nitriding treatment time and the thickness of the soft nitrided layer formed is as shown in a of FIG.
上記したテストピースを上記防錆洗浄液で洗
浄後、加熱せずにガス軟窒化炉に入れて軟窒化
処理した。この場合の軟窒化処理時間と軟窒化
層の厚さの相関関系は第１図のｂに示す通りで
ある。 After cleaning the test piece with the anti-rust cleaning solution, it was placed in a gas soft-nitriding furnace without heating and subjected to soft-nitriding treatment. In this case, the correlation between the soft-nitriding treatment time and the thickness of the soft-nitrided layer is as shown in FIG. 1b.
上記ａとｂの関係から明らかなように、軟窒
化処理前に加熱して酸化被膜を形成しておく
と、酸化被膜を形成しない場合に比較して同一
の軟窒化処理時間では60％程度、軟窒化層の厚
さが厚くなつてる。よつて、従来と同一の軟窒
化処理時間をかけると厚い軟窒化層が得られ、
鋳鉄材の表面の耐摩耗性が大巾に向上し、一
方、従来と同一厚さの軟窒化層を得る場合には
軟窒化処理に要する時間を大巾に短縮できる。 As is clear from the relationship between a and b above, if an oxide film is formed by heating before nitrocarburizing, compared to the case where an oxide film is not formed, the nitrocarburizing treatment time is approximately 60% lower than when an oxide film is not formed. The thickness of the nitrocarburized layer becomes thicker. Therefore, a thick soft-nitrided layer can be obtained by applying the same soft-nitriding time as conventional methods,
The wear resistance of the surface of the cast iron material is greatly improved, and on the other hand, when obtaining a soft nitrided layer with the same thickness as before, the time required for soft nitriding treatment can be greatly shortened.
（） 上記（）と同一の鋳鉄材テストピース
を鋳造し、鉱油系エマルジヨンタイプの防錆洗
浄液で洗浄し、ついで、第２図のグラフの横軸
に示す如く、加熱温度を変えて酸化処理し、そ
の後常温まで温度の下つたテストピースをガス
軟窒化炉（NH3ガス：Rxガス＝60：40）で、
570℃で４時間軟窒化処理した。その時の軟窒
化層の厚さは第２図中の（）で示す如くであ
つた。即ち、400℃以下の加熱では軟窒化層の
厚さ増大効果は得られず、加熱なしの場合と殆
んど変らない。400℃を越えると軟窒化層の厚
さ増大効果が急激に大きくなつていることがわ
かる。しかし、500℃を越えると、鋳鉄材では
前述した通り、基地と黒鉛との境界部で表面の
荒れが著しくなり、仕上加工の困軟性も増大し
実用的でなくなる。第２図中の（）は加熱処
理後に冷却せずに装入した場合を示し、加熱処
理後冷却した場合に比較して軟窒化層の厚みは
大となつている。() The same cast iron test piece as in () above was cast, washed with a mineral oil-based emulsion type anti-rust cleaning solution, and then oxidized by changing the heating temperature as shown on the horizontal axis of the graph in Figure 2. After that, the test piece was cooled down to room temperature in a gas soft nitriding furnace (NH 3 gas: Rx gas = 60:40).
Soft-nitriding treatment was performed at 570°C for 4 hours. The thickness of the nitrocarburized layer at that time was as shown in parentheses in FIG. That is, heating at 400° C. or lower does not increase the thickness of the nitrocarburized layer, and there is almost no difference from the case without heating. It can be seen that when the temperature exceeds 400°C, the effect of increasing the thickness of the nitrocarburized layer increases rapidly. However, when the temperature exceeds 500°C, as mentioned above, the surface of the cast iron material becomes noticeably rough at the interface between the matrix and the graphite, and the difficulty of finishing increases, making it impractical. () in FIG. 2 shows the case where the material was charged without being cooled after the heat treatment, and the thickness of the nitrocarburized layer was larger than that in the case where the material was cooled after the heat treatment.
以上の説明より明らかなように、この発明に係
る軟窒化法によれば、軟窒化処理前に予備酸化処
理を行つているため、同一の軟窒化処理時間で従
来と比較して30％程度軟窒化層の厚さが大とな
り、品質が向上し、又、大巾な処理時間の短縮が
図れ、コストダウンができる利点を有する。 As is clear from the above explanation, according to the soft nitriding method of the present invention, the preliminary oxidation treatment is performed before the soft nitriding process, so the soft nitriding process is approximately 30% softer than the conventional soft nitriding process for the same soft nitriding time. This has the advantage that the thickness of the nitrided layer is increased, the quality is improved, and the processing time can be greatly shortened, resulting in cost reduction.
第１図は窒化処理時間と軟窒化層の相関関係を
示すグラフ、第２図は窒化前加熱温度と軟窒化層
の相関関係を示すグラフである。
FIG. 1 is a graph showing the correlation between the nitriding treatment time and the soft-nitrided layer, and FIG. 2 is a graph showing the correlation between the pre-nitriding heating temperature and the soft-nitrided layer.
Claims (1)
鋳鉄材を400〜500℃に加熱して表面にFe2O3を主
成分とする鉄の酸化被膜を形成し、しかる後にそ
の鋳鉄材を軟窒化処理して表面に軟窒化層を形成
することを特徴とする鋳鉄材の軟窒化法。 ２ 特許請求の範囲第１項記載の防錆洗浄液が、
酸化被膜を形成するための加熱時に燃焼する鉱油
系エマルジヨンタイプの洗浄液であることを特徴
とする鋳鉄材の軟窒化法。[Claims] 1. The surface of a cast iron material is cleaned with an anti-corrosion cleaning solution, and then the cast iron material is heated to 400 to 500°C to form an iron oxide film containing Fe 2 O 3 as the main component on the surface. A method of nitrocarburizing cast iron material, which is characterized in that the cast iron material is then subjected to nitrocarburizing treatment to form a nitrocarburized layer on the surface. 2. The anti-rust cleaning liquid according to claim 1,
A soft nitriding method for cast iron materials characterized by a mineral oil-based emulsion type cleaning liquid that burns during heating to form an oxide film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4145679A JPS55134172A (en) | 1979-04-04 | 1979-04-04 | Soft-nitriding method for iron base material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4145679A JPS55134172A (en) | 1979-04-04 | 1979-04-04 | Soft-nitriding method for iron base material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55134172A JPS55134172A (en) | 1980-10-18 |
| JPS6341982B2 true JPS6341982B2 (en) | 1988-08-19 |
Family
ID=12608867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4145679A Granted JPS55134172A (en) | 1979-04-04 | 1979-04-04 | Soft-nitriding method for iron base material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55134172A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| PL132768B3 (en) * | 1980-07-04 | 1985-04-30 | Inst Mech Precyz | Method of thermochemical treatment of cutting tools and tools for plastic working |
| JPH0784639B2 (en) * | 1990-09-04 | 1995-09-13 | 日栄鋼材株式会社 | Gas composite permeation reforming method |
| JP5731107B2 (en) * | 2009-07-01 | 2015-06-10 | 本田技研工業株式会社 | Nitriding member and manufacturing method thereof |
| US9334977B2 (en) | 2012-10-30 | 2016-05-10 | Nittan Valve Co., Ltd. | Engine valve |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5544516A (en) * | 1978-09-21 | 1980-03-28 | Honda Motor Co Ltd | Soft-nitriding method with gas |
-
1979
- 1979-04-04 JP JP4145679A patent/JPS55134172A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5544516A (en) * | 1978-09-21 | 1980-03-28 | Honda Motor Co Ltd | Soft-nitriding method with gas |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55134172A (en) | 1980-10-18 |
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