JPS6130660A - Method for subjecting high-alloy steel member to gas soft-nitriding - Google Patents
Method for subjecting high-alloy steel member to gas soft-nitridingInfo
- Publication number
- JPS6130660A JPS6130660A JP15178384A JP15178384A JPS6130660A JP S6130660 A JPS6130660 A JP S6130660A JP 15178384 A JP15178384 A JP 15178384A JP 15178384 A JP15178384 A JP 15178384A JP S6130660 A JPS6130660 A JP S6130660A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- alloy steel
- nitriding
- treatment
- gas soft
- 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.)
- Pending
Links
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
- C23C8/08—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 only one element being applied
- C23C8/24—Nitriding
- C23C8/26—Nitriding of ferrous surfaces
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)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、高合金鋼部材のガス軟窒化処理方法に関し、
詳しくは、予め、゛冷間加工もしくは低温時効処理され
た高合金鋼部材の冷間加工効果もしくは低温時効処理効
果を損なうことなく、上述の冷間強化処理に加えて、さ
らに、曲げ疲労強度を著しく向上させることのできる高
合金鋼部材のガス軟窒化処理方法にかかる。[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for gas nitrocarburizing treatment of high alloy steel members.
Specifically, in addition to the above-mentioned cold strengthening treatment, the bending fatigue strength is further increased without impairing the cold working effect or the low temperature aging treatment effect of the high alloy steel member that has been cold worked or low temperature aging treated. The present invention relates to a gas nitrocarburizing treatment method for high alloy steel members that can be significantly improved.
従来、鋼や鋳鉄の疲労強度を改善するために実施されて
いるガス軟窒化処理方法は、通常、５５０〜６００℃の
高温で処理されていることから、高合金鋼部材に冷間加
工や低温時効処理等の低温強化処理を実施された高合金
鋼部材においては、その冷間加工効果が消滅してしまっ
たり、時効処理を施こされた高合金鋼部材、とりわけ、
４８０〜５１０℃の低温温度域で低温時効処理された高
合金鋼部材においては、過時効となって硬さや曲げ疲労
強度が低下してしまう。Conventionally, gas nitrocarburizing treatment methods that have been used to improve the fatigue strength of steel and cast iron are usually treated at high temperatures of 550 to 600°C. In high-alloy steel members that have undergone low-temperature strengthening treatment such as aging treatment, the cold working effect may disappear, and in high-alloy steel members that have undergone aging treatment, especially
In high-alloy steel members subjected to low-temperature aging treatment in the low-temperature range of 480 to 510°C, hardness and bending fatigue strength deteriorate due to overaging.
また、従来のガス軟窒化処理方法においてはその処理温
度が高いことから、ガス軟窒化処理に伴う被処理部材で
ある高合金鋼部材の変寸・変形等の歪も大きくなる′等
の問題点があった。In addition, in the conventional gas soft nitriding treatment method, the processing temperature is high, so there are problems such as increased distortion due to dimensional change and deformation of the high alloy steel member that is the treated member due to the gas soft nitriding treatment. was there.
これらの従来のガス軟窒化処理における問題を発生させ
ないためには、低温（例えば、５５０℃以下）でガス軟
窒化処理することが望ましいものの、処理温度が低くな
ると窒化速度も低下するという問題点があった。In order to avoid these problems with conventional gas soft nitriding, it is desirable to perform gas soft nitriding at a low temperature (for example, 550°C or lower), but the problem is that the lower the treatment temperature, the lower the nitriding speed. there were.
ところで、従来のガス軟窒化処理方法においても、吸熱
型ガスにアンモニヤガスを添加した雰囲気中に、微量の
空気もしくは酸素を添加することによって、低温におけ
る浸炭及び窒化反応を促進する方法〔例えば、「熱処理
」１６巻３号（昭和５１年６月）Ｐ１４０〜〕、アンモ
ニヤガス中に体積比率で０．５〜５％の空気もしくは０
．１〜１％の酸素を添加したガス軟窒化処理雰囲気中に
て、温度４５０〜６５０℃の範囲で処理するガス軟窒化
処理方法（例えば、特公昭４９−３０３３９号）、−酸
化炭素とアンモニヤガスを主成分とする混合ガスに、体
積比率で５〜１０％の空気もしくは１〜２％の酸素を添
加した浸炭窒化性ガスを使用したガス軟窒化処理方法（
例えば、特公昭４９−４６４６２号）等の、ガス軟窒化
処理温度を低温化する方法が試みられている。By the way, in the conventional gas nitrocarburizing treatment method, the carburizing and nitriding reactions at low temperatures are promoted by adding a trace amount of air or oxygen to an atmosphere in which ammonia gas is added to an endothermic gas [for example, ""HeatTreatment" Vol. 16 No. 3 (June 1976) P140~], 0.5 to 5% air by volume in ammonia gas or 0.
．． A gas soft nitriding method (for example, Japanese Patent Publication No. 49-30339) in which the process is carried out in a gas soft nitriding atmosphere containing 1 to 1% oxygen at a temperature in the range of 450 to 650°C, - Carbon oxide and ammonia gas A gas nitrocarburizing treatment method using a carbonitriding gas prepared by adding 5 to 10% air or 1 to 2% oxygen by volume to a mixed gas whose main component is
For example, a method of lowering the gas soft nitriding temperature has been attempted, such as Japanese Patent Publication No. 49-46462).
しかし、上述のような酸素を添加して軟窒化反応を促進
するガス軟窒化処理方法においては、いずれも、体積比
率で４．０％を越える空気の添加を許容している。However, in the gas nitrocarburizing treatment methods described above in which the nitrocarburizing reaction is promoted by adding oxygen, the addition of air exceeding 4.0% by volume is allowed.
また、被処理部材として高合金鋼部材、とりわけ、マル
エージング鋼のような高合金鋼部材に適合した処理条件
を明らかにしているガス軟窒化処理方法は未だ発表され
ていない。Further, no gas soft nitriding treatment method has yet been published that specifies treatment conditions suitable for high alloy steel members, particularly high alloy steel members such as maraging steel, as the member to be treated.
本発明は、上述のような従来技術の問題点を解決するた
めになされたもので、高合金鋼部材に適合した処理条件
であって、しかも、従来のガス軟窒化処理より低温（５
５０℃以下）においてガス軟窒化処理することにより、
ガス軟窒化処理前に施された冷間加工や低温時効処理の
低温強化処理効果を損なうことなく、冷間加工や低温時
効処理の低温強化処理効果にガス軟窒化処理の効果を付
加させることによって、高合金鋼部材の曲げ疲労強度を
著しく向上させることのできる高合金鋼部材のガス軟窒
化処理方法を提供することを目的としている。The present invention was made to solve the problems of the prior art as described above, and has processing conditions suitable for high-alloy steel members, and at a lower temperature (55%) than the conventional gas nitrocarburizing treatment.
By performing gas nitrocarburizing treatment at a temperature below 50℃,
By adding the effect of gas soft nitriding treatment to the low temperature strengthening treatment effect of cold working and low temperature aging treatment without impairing the low temperature strengthening treatment effect of cold working and low temperature aging treatment performed before gas soft nitriding treatment. The object of the present invention is to provide a method for gas nitrocarburizing treatment of high-alloy steel members, which can significantly improve the bending fatigue strength of high-alloy steel members.
このような目的は、本発明によれば、予め、冷間加工も
しくは低温時効処理された高合金鋼部材を、ガス軟窒化
処理することによって曲げ疲労強度を改善する高合金鋼
部材のガス軟窒化処理方法であって、
前記高合金鋼部材を冷間加工もしくは低温時効処理され
た高合金鋼部材とし、ガス軟窒化処理雰囲気を吸熱型ガ
スとアンモニアガスの混合ガス中に、空気を体積比率で
０．１〜４．０％添加した雰囲気として、４００〜５５
０℃においてガス軟窒化処理することを特徴とする高合
金鋼部材のガス軟窒化処理方法によって達成される。According to the present invention, the present invention aims to improve the bending fatigue strength of high-alloy steel members by performing gas soft-nitriding treatment on high-alloy steel members that have been previously subjected to cold working or low-temperature aging treatment. In the treatment method, the high-alloy steel member is a high-alloy steel member that has been cold-worked or low-temperature aging treated, and the gas nitrocarburizing treatment atmosphere is a mixed gas of endothermic gas and ammonia gas, and air is added at a volume ratio. 400 to 55 as an atmosphere containing 0.1 to 4.0%
This is achieved by a method for gas soft-nitriding treatment of high alloy steel members, which is characterized by performing gas soft-nitriding treatment at 0°C.
以下、本発明の作用について説明する。 Hereinafter, the effects of the present invention will be explained.
本発明法において、被処理部材として高合金鋼部材とし
ているのは、冷間加工及び低温時効処理等の低温強化処
理効果を最大限に発揮させるためである。In the method of the present invention, a high-alloy steel member is used as the member to be treated in order to maximize the effects of low-temperature strengthening treatments such as cold working and low-temperature aging treatment.
また、本発明法においてガス軟窒化処理のための雰囲気
を、吸熱型ガスとアンモニアガスの混合ガス中に、空気
を体積比率で０．１〜４．０％添加した雰囲気としてい
るのは、吸熱型ガスとアンモニアガスの混合ガスは、ガ
ス軟窒化処理中における被処理部材である高合金鋼部材
への炭素及び窒素を侵入拡散を容易とするためと、被処
理部材である高合金鋼部材の酸化を防止するためであり
、また、空気を体積比率で０．１〜４．０％添加してい
るのは、第１図に示すように、０．１％未満では添加に
よる軟窒化反応促進の効果が充分でなく、４．０％を越
えるとガス軟窒化処理により形成される化合物層厚さが
それに見合って増加しないばかりでなく、ガス軟窒化処
理中において被処理部材である高合金綱部材の酸化を生
じ易くなるからである。In addition, in the method of the present invention, the atmosphere for gas nitrocarburizing treatment is an atmosphere in which 0.1 to 4.0% by volume of air is added to a mixed gas of endothermic gas and ammonia gas. The mixed gas of mold gas and ammonia gas is used to facilitate the penetration and diffusion of carbon and nitrogen into the high-alloy steel member to be treated during the gas soft-nitriding treatment, and to facilitate the diffusion of carbon and nitrogen into the high-alloy steel member to be treated during the gas soft-nitriding process. This is to prevent oxidation, and the reason why air is added in a volume ratio of 0.1 to 4.0% is as shown in Figure 1.If it is less than 0.1%, the nitrocarburizing reaction is accelerated. If it exceeds 4.0%, not only will the thickness of the compound layer formed by gas soft nitriding not increase commensurately, but also the high alloy steel that is the treated member during gas soft nitriding. This is because oxidation of the member is likely to occur.
〔実施例〕
以下、添付図面に基づいて、本発明の１実施例を説明す
る。[Embodiment] Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.
この実施例においては、下表に示すような組成を有する
２種類のマルエージング鋼製無段変速機用無端金属フー
プの試験片を用いて、後述のような処理条件として低温
時効処理とガス軟窒化処理を実施した。In this example, test pieces of two types of maraging steel endless metal hoops for continuously variable transmissions having the compositions shown in the table below were used. Nitriding treatment was carried out.
表
注）なお、Ｓｉ、Ｍｎ、Ｐ、Ｓ、Ｂ、Ｚｒ、Ｃａは、試
料■及び試料■において、いずれも等しい含有量であり
、それぞれ、５ｉＢ０．１０％２Ｍｎ ； ０．１０％
、ＰｉＯ，０１０％、Ｓｉ０．０１０％。Table note) In addition, Si, Mn, P, S, B, Zr, and Ca have the same content in sample ■ and sample ■, respectively, 5iB0.10%2Mn; 0.10%
, PiO, 010%, Si 0.010%.
Ｂ；０．００３％、ＺｒＨｏ、０２％、Ｃａ；０．０５
％である。B; 0.003%, ZrHo, 02%, Ca; 0.05
%.
この実施例においては、まず、試料■及び試料■をとも
に４８０〜ｂ
時効処理を実施した。In this example, first, sample (1) and sample (2) were both subjected to 480-b aging treatment.
その後、上記における試料■に対しては、吸熱型ガス；
７．５１ ／ｍｉｎ 、アンモニヤガス；８．７５１
／ １ｎ ＋ 空気；０，３１／ｌｌ１ｉｎのガス軟
窒化処理雰囲気にて、４９０°ｃｘ１５分のガス軟窒化
処理を施し、ついで、上記雰囲気中にて３００℃まで冷
却した後、アルゴンガスに切り換えて１００℃まで冷却
した。After that, for sample ① in the above, an endothermic gas;
7.51/min, ammonia gas; 8.751
/ 1n + air: Perform gas soft nitriding treatment at 490°C x 15 minutes in a gas soft nitriding treatment atmosphere of 0.31/ll1in, then cool to 300°C in the above atmosphere, and then switch to argon gas. Cooled to 100°C.
ちなみに、本発明法における上述のような処理条件によ
りガス軟窒化処理された高合金鋼部材の金属組織を示す
顕微鏡写真を第２図に示す。Incidentally, FIG. 2 shows a micrograph showing the metal structure of a high alloy steel member subjected to gas nitrocarburizing treatment under the above-mentioned treatment conditions in the method of the present invention.
第２図から明らかなように、本発明法によりガス軟窒化
処理された高合金鋼部材に形成される化合物層厚さは１
６〜１７μとなっている。As is clear from Fig. 2, the thickness of the compound layer formed on the high alloy steel member subjected to gas nitrocarburizing treatment by the method of the present invention is 1
It is 6 to 17μ.
また、上記における試料■に対しても、上述の低温時効
処理後、試料■と同様の吸熱型ガス；７゜５１／＋ｗｉ
ｎ、アンモニヤガス；８．７５１／ａ＋ｉｎ。In addition, for the above sample ■, after the above-mentioned low temperature aging treatment, the same endothermic gas as sample ■; 7°51/+wi
n, ammonia gas; 8.751/a+in.
空気ｉ０．３１／ｓｉｎのガス軟窒化処理雰囲気にて、
４２０℃×６０分のガス軟窒化処理を施し、ついで、試
料■と同様に、上記雰囲気中にて３００℃まで冷却した
後、アルゴンガスに切り換えて１００℃まで冷却した。In a gas nitrocarburizing atmosphere of air i0.31/sin,
A gas nitrocarburizing treatment was performed at 420° C. for 60 minutes, and then, similarly to sample ①, the sample was cooled to 300° C. in the above atmosphere, and then switched to argon gas and cooled to 100° C.
次に、上述のように低温時効処理した後ガス軟窒化処理
を実施した、試料■及び試料■、並びに、従来の高温ガ
ス軟窒化処理した試料を用いて、引張応力；σｔ ＝
３０ Ｋｇ／ｍａｄ” 、曲げ応力；σＢ＝１３５ Ｋ
ｇ／ｍｍ２の試験条件のもとで曲げ疲労強度試験を実施
した。Next, tensile stress; σt =
30 Kg/mad”, bending stress; σB=135 K
A bending fatigue strength test was conducted under test conditions of g/mm2.
この試験結果を第３図に示す。The test results are shown in FIG.
この試験結果から明らかなように、従来法によりガス軟
窒化処理した無端金属フープ試験片は、２．０Ｘ１０’
回の繰り返し数で破断したのに対し、本発明法によりガ
ス軟窒化処理した無端金属フープ試験片は、５．２Ｘ１
０’回の繰り返し数においても破断することなく、曲げ
疲労強度寿命が２５倍以上に改善されていることが理解
される。As is clear from this test result, the endless metal hoop specimen treated with gas nitrocarburizing by the conventional method was 2.0×10'
In contrast, the endless metal hoop specimen treated by gas nitrocarburizing according to the method of the present invention broke after 5.2×1
It is understood that the bending fatigue strength life is improved by more than 25 times without breaking even after 0' repetitions.
以上により明らかなように、本発明にかかる高合金鋼部
材のガス軟窒化処理方法によれば、高合金鋼部材に適合
した処理条件であって、しかも、従来のガス軟窒化処理
より低温（５５０℃以下）においてガス軟窒化処理する
ことにより、ガス軟窒化処理前に施された冷間加工や低
温時効処理の低温強化処理効果を損なうことなく、冷間
加工や低温時効処理の効果にガス軟窒化処理の効果を付
加させることによって、高合金鋼部材の曲げ疲労強度を
著しく向上させることができる利点がある。As is clear from the above, according to the gas soft-nitriding method for high-alloy steel members according to the present invention, the treatment conditions are suitable for high-alloy steel members, and the temperature is lower (550°C) than the conventional gas soft-nitriding treatment. By performing gas soft nitriding at temperatures below By adding the effect of nitriding treatment, there is an advantage that the bending fatigue strength of high alloy steel members can be significantly improved.
第１図は、本発明法によるガス軟窒化処理における空気
添加量と化合物層厚さの関係を示すグラフ。
第２図は、本発明法によりガス軟窒化処理した高合金鋼
部材の金属組織を示す顕微鏡写真。
第３図は、従来法と本発明法によりガス軟窒化処理した
無端金属フープ試験片による曲げ疲労強度試験結果を示
すグラフである。
ａ−−−−−・化合物層。
Ａ−−・−被処理部材の酸化領域。FIG. 1 is a graph showing the relationship between the amount of air added and the thickness of the compound layer in the gas nitrocarburizing treatment according to the method of the present invention. FIG. 2 is a micrograph showing the metal structure of a high-alloy steel member subjected to gas soft-nitriding according to the method of the present invention. FIG. 3 is a graph showing the results of a bending fatigue strength test using endless metal hoop specimens subjected to gas nitrocarburizing by the conventional method and the method of the present invention. a-----Compound layer. A-- Oxidized region of the member to be treated.
Claims (1)
鋼部材を、ガス軟窒化処理することによって曲げ疲労強
度を改善する高合金鋼部材のガス軟窒化処理方法であっ
て、 前記高合金鋼部材を冷間加工もしくは低温時効処理され
た高合金鋼部材とし、ガス軟窒化処理雰囲気を吸熱型ガ
スとアンモニアガスの混合ガス中に、空気を体積比率で
０．１〜４．０％添加した雰囲気として、４００〜５５
０℃においてガス軟窒化処理することを特徴とする高合
金鋼部材のガス軟窒化処理方法。[Claims] 1. A method for gas soft-nitriding treatment of high-alloy steel members, which improves bending fatigue strength by performing gas soft-nitriding treatment on high-alloy steel members that have been previously subjected to cold working or low-temperature aging treatment. The high alloy steel member is a high alloy steel member that has been cold-worked or low-temperature aging treated, and the gas nitrocarburizing treatment atmosphere is a mixed gas of endothermic gas and ammonia gas, and air is added at a volume ratio of 0.1 to As an atmosphere with 4.0% addition, 400 to 55
A method for gas soft-nitriding treatment of high-alloy steel members, characterized by performing gas soft-nitriding treatment at 0°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15178384A JPS6130660A (en) | 1984-07-20 | 1984-07-20 | Method for subjecting high-alloy steel member to gas soft-nitriding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15178384A JPS6130660A (en) | 1984-07-20 | 1984-07-20 | Method for subjecting high-alloy steel member to gas soft-nitriding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6130660A true JPS6130660A (en) | 1986-02-12 |
Family
ID=15526200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15178384A Pending JPS6130660A (en) | 1984-07-20 | 1984-07-20 | Method for subjecting high-alloy steel member to gas soft-nitriding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6130660A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62192528A (en) * | 1986-02-19 | 1987-08-24 | Toyota Central Res & Dev Lab Inc | Manufacture of maraging steel member having superior wear resistance and fatigue strength |
| JPS63176430A (en) * | 1987-01-14 | 1988-07-20 | Honda Motor Co Ltd | Manufacture of coil spring |
| JP2007168832A (en) * | 2005-12-21 | 2007-07-05 | Fuji Seal International Inc | Package for microwave-heating |
-
1984
- 1984-07-20 JP JP15178384A patent/JPS6130660A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62192528A (en) * | 1986-02-19 | 1987-08-24 | Toyota Central Res & Dev Lab Inc | Manufacture of maraging steel member having superior wear resistance and fatigue strength |
| JPH0582452B2 (en) * | 1986-02-19 | 1993-11-19 | Toyoda Chuo Kenkyusho Kk | |
| JPS63176430A (en) * | 1987-01-14 | 1988-07-20 | Honda Motor Co Ltd | Manufacture of coil spring |
| JP2007168832A (en) * | 2005-12-21 | 2007-07-05 | Fuji Seal International Inc | Package for microwave-heating |
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