JPS6330395B2 - - Google Patents
Info
- Publication number
- JPS6330395B2 JPS6330395B2 JP18194881A JP18194881A JPS6330395B2 JP S6330395 B2 JPS6330395 B2 JP S6330395B2 JP 18194881 A JP18194881 A JP 18194881A JP 18194881 A JP18194881 A JP 18194881A JP S6330395 B2 JPS6330395 B2 JP S6330395B2
- Authority
- JP
- Japan
- Prior art keywords
- carburizing
- powder
- gas
- sintered iron
- particle size
- 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
- 238000005255 carburizing Methods 0.000 claims description 64
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 58
- 239000000843 powder Substances 0.000 claims description 29
- 229910052742 iron Inorganic materials 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 22
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 9
- 239000011812 mixed powder Substances 0.000 claims description 8
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 239000007789 gas Substances 0.000 description 33
- 239000002245 particle Substances 0.000 description 17
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 14
- 239000000203 mixture Substances 0.000 description 14
- 229910000831 Steel Inorganic materials 0.000 description 8
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000001294 propane Substances 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 239000006229 carbon black Substances 0.000 description 4
- 238000010791 quenching Methods 0.000 description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 235000013162 Cocos nucifera Nutrition 0.000 description 1
- 244000060011 Cocos nucifera Species 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 239000010723 turbine oil Substances 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 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
- C23C8/60—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 solids, e.g. powders, pastes
- C23C8/62—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 solids, e.g. powders, pastes only one element being applied
- C23C8/64—Carburising
- C23C8/66—Carburising of ferrous surfaces
Description
本発明は焼結鉄部材の浸炭法に関する。
一般に焼結鉄は、その表面から内部へ通じる空
孔が多いため、浸炭処理の際に、これら空孔を通
じて浸炭性ガスが急速に浸透し、次いで表面拡散
作用による迅速なカーボンの拡散合金化が起こ
る。従つて、通常の鋼材の場合と異なり、深く且
つ不均一に浸炭され易く、一定の深さに浸炭をす
ることが困難である。また、焼結鉄部材は鉄鋼部
材に比して、その形状及び寸法が複雑で小型であ
りしかも少量多種にわたる場合が多い。従つて、
焼結鉄部材の浸炭法としては、焼結鉄表面部に短
時間に一定の浸炭層を形成でき且つ浸炭処理条件
の設定を容易にしかも正確に行ない得る方法が望
まれている。
従来、焼結鉄部材の浸炭処理法としては短時間
に浸炭層を形成できることからガス浸炭法が多用
されて来た。しかしながら、ガス浸炭法はガス組
成の制御に高度な技術と熟練を要し、そのため処
理条件の設定変更に伴つて往々にして品質の不安
定を招くという欠点を有している。
本発明の目的は、上記ガス浸炭法の欠点を克服
し、高度な技術と熟練を必要とせずに極めて容易
な操作で正確に浸炭処理条件の設定変更ができ、
しかもガス浸炭法と同程度に短時間で効果的に処
理でき且つ品質の安定した製品の得られる焼結鉄
部材の浸炭法を提供するところにある。
即ち、本発明は、浸炭処理条件下で実質的に変
化しない耐火物粉末に炭素を主体とした浸炭剤粉
末を配合した混合粉末に焼結鉄を埋没せしめ、２
〜90％の一酸化炭素を含むガスを雰囲気とする加
熱炉内に於いて浸炭処理を行なうことを特徴とす
る焼結鉄部材の浸炭法に係る。
本発明の浸炭法の浸炭反応は次に示す二つの化
学反応が同時に右方向に進行することにより起こ
る。
(1)及び(2)式の反応が右方向に進行する割合をよ
り高めるためには、一酸化炭素の供給を多くし且
つ二酸化炭素とカーボンの反応が迅速に行なわれ
る必要がある。本発明はこれらの点をいずれも満
足するものである。
本発明に於いては、耐火物粉末に、炭素を主体
とした浸炭剤粉末を配合した混合粉末が使用され
る。この際の浸炭剤粉末としては、固体浸炭法で
用いる固体浸炭法（例えば、やしがら炭やカーボ
ンブラツク等に炭酸バリウム等の浸炭促進剤を配
合したもの）と同等のものを用いることができる
が、その粉末粒度としては、小さいものほど粉末
の比表面積が大きく雰囲気ガスと迅速に反応して
浸炭能力が高まるため、200メツシユ篩下の微粉
末を用いるのが好ましい。また、耐火物粉末とし
ては、浸炭条件下で実質的に変化しないものを広
く使用でき、例えばアルミナ、マグネシア、シリ
カ、ジルコンサンド又はこれらの混合物若しくは
化合物等を挙げることができる。耐火物粉末の粒
度としては、浸炭剤粉末との混合粉末の通気性を
高め雰囲気ガスが浸透し易く浸炭作用が充分に発
揮されるために、20メツシユ篩下であるのが好ま
しく、20メシユ篩下〜80メツユ篩上であるのが特
に好ましい。かかる耐火物粉末は、浸炭剤粉末を
分散させて相互固着を防止し浸炭能力を効果的に
発揮させる。また、処理時の加熱を平均化させる
という効果も有する。
耐火物粉末と浸炭剤粉末の配合割合は特に限定
がなく用途に応じて広い範囲で適宜選択される
が、浸炭能力、経済性及び作業性等の点から、混
合粉末中に後者を２〜60重量％含有せしめるのが
好ましく、６〜24重量％含有せしめるのが特に好
ましい。
本発明に於ける雰囲気ガスとしては、２〜90％
の範囲で一酸化炭素を含有するメタン、プロパ
ン、ブタン等の炭化水素の変成ガス、都市ガス等
を使用することができる。一酸化炭素が２％以下
では、一酸化炭素の絶対量が少ないため浸炭反応
が進行しにくく経済的でなく、90％以上では一酸
化炭素が分解しススを生じるため作業性が劣化す
る。
雰囲気ガスは、浸炭度合が使用するガスの組成
により異なるため、用途に応じて適宜選択され
る。
浸炭温度と処理時間は、焼結鉄の種類、大き
さ、数等により適宜選択されるが通常800〜1000
℃、15分〜２時間である。浸炭終了後は、常法に
従つて焼入れ硬化される。
従来のガス浸炭処理に於いては、雰囲気ガスの
使用中にその組成割合が多少変動するため、浸炭
能力が低下したり逆に過剰浸炭されたりして、品
質が不安定となる要因となつていた。然るに、本
発明の浸炭法では、雰囲気ガスの組成割合が多少
変動しても、浸炭剤周辺での浸炭剤と雰囲気ガス
の反応により、浸炭能力がかなりの程度調整され
るので、従来のガス浸炭処理の場合に比して浸炭
度合は一定しており品質が安定する。本発明の浸
炭法は、一見して固体浸炭法の様に考えられる
が、むしろガス浸炭法に近く、その浸炭反応はガ
ス浸炭法と同等以上に迅速であり効果的である。
本発明の浸炭法は、浸炭処理条件の設定に際し
て特に高度の技術や熟練を要せず容易に且つ安定
して行なえるので、大量生産品は勿論のこと多種
少量生産品の浸炭処理にも適している。尚、浸炭
処理用混合粉末は繰り返し使用できるが、カーボ
ンが次第に目減りするので時折りカーボンを補充
添加して浸炭能力の安定化を図ることが望まし
い。
次に実施例及び比較例を挙げて本発明を更に具
体的に説明する。尚ここで用いた焼結鉄は次の方
法により製造したものである。
ニツケル粉：平均粒度5μｍ
カーボン（黒鉛粉）：平均粒度10μｍ
モリブデン粉：平均粒度1μｍ
鉄粉：粒度100メツシユ以下
上記粉末を適宜配合したもの100部に対しステ
アリン酸亜鉛粉１部を潤滑剤として加えて配合
し、6ton／cm2の圧力で成形後、分解アンモニアガ
ス中1180℃で１時間加熱焼結して、各焼結鉄を得
た。
実施例 １
組成：２％ニツケル、0.2％カーボン、残部鉄、
密度：7.0ｇ／cm3、寸法形状：φ11.3×15mm円柱の
焼結鉄を、アルミナ粉末（粒度約60メツシユ）に
カーボンブラツク粉末（粒度200メツシユ篩下）
７％及び炭酸バリウム粉末（粒度200メツシユ篩
下）３％を配合した混合粉末を入れた鋼板製容器
内に埋没せしめ、該容器をプロパン変性ガス（ガ
ス組成CO≒24％、H2≒32％、N2≒44％）の存在
下、880℃に加熱した炉内に配置して90分間浸炭
処理を行つた。得られた浸炭処理済み焼結鉄を、
再びプロパン変成ガス（ガス組成同上）を満たし
850℃に加熱した炉内に鋼板製容器に入れて配置
し60分間加熱後タービン油（140#）中に焼入れ
た。さらに得られた焼入れ品を窒素ガスを満たし
200℃に加熱した炉内に、鋼板製溶器に入れて配
置し60分間焼もどし後空冷した。得られた浸炭焼
入れ処理焼結鉄について表面マクロ硬さ（ロツク
ウエルＡスケール）および試料断面のミクロ硬さ
（マイクロビツカース100ｇ／15sec）を測定して、
浸炭度合あるいは焼入れ硬化度合を調べた結果を
第１表に示す。
比較例 １
比較のための実施例１と同一の焼結鉄に従来の
ガス浸炭焼入れ処理（雰囲気ガスとして実施例１
で用いたものにプロパンを３％加えたものを用い
た。浸炭処理880℃×90min、850℃に降温後油中
焼入れ、焼もどし処理200℃×60min）を施した
場合についての結果を第１表に示す。
実施例 ２
組成：４％ニツケル、0.5％モリブデン、0.2％
カーボン、残部鉄、密度：7.0ｇ／cm3、寸法形
状：φ11.3×15mm円柱の焼結鉄をアルミナ粉末
（粒度約60メツシユ）にカーボンブラツク粉末
（粒度200メツシユ篩下）４％及び炭酸バリウム粉
末（粒度200メツシユ篩下）２％を配合した混合
粉末を入れた鋼板製容器内に埋没せしめ、該容器
をプロパン変性ガス（組成24％CO、32％H2、44
％N2）の存在下、880℃に加熱した炉内に配置し
て60分間浸炭処理を行つた。得られた浸炭処理済
み焼結鉄に実施例１と同等の焼入れおよび焼きも
どし処理を施した。第１表にマクロ硬さとミクロ
硬さ測定の結果を示す。
比較例 ２
比較のため実施例２と同一の焼結鉄に従来のガ
ス浸炭焼入れ処理（雰囲気ガスとして実施例１で
用いたものにプロパンを３％加えたものを用い
た。浸炭処理880℃×60min、850℃に降温後油中
焼入れ、焼もどし処理200℃×60min）を施した
場合についての結果を第１表に示す。
The present invention relates to a method for carburizing sintered iron parts. Generally, sintered iron has many pores leading from the surface to the inside, so during carburizing treatment, carburizing gas rapidly penetrates through these pores, and then carbon diffuses rapidly into alloys due to surface diffusion. happen. Therefore, unlike ordinary steel materials, it is likely to be carburized deeply and unevenly, making it difficult to carburize to a constant depth. Furthermore, compared to steel members, sintered iron members are more complex in shape and size, are smaller, and are often produced in small quantities and in many different types. Therefore,
As a carburizing method for sintered iron members, a method is desired that can form a certain carburized layer on the surface of the sintered iron in a short period of time and can easily and accurately set carburizing treatment conditions. Conventionally, gas carburizing has been frequently used as a carburizing method for sintered iron members because it can form a carburized layer in a short time. However, the gas carburizing method requires advanced technology and skill to control the gas composition, and therefore has the disadvantage that changing the processing conditions often causes instability in quality. The purpose of the present invention is to overcome the drawbacks of the above-mentioned gas carburizing method, and to enable setting of carburizing treatment conditions to be changed accurately with extremely easy operation without requiring advanced technology or skill.
Moreover, it is an object of the present invention to provide a carburizing method for sintered iron members that can be processed effectively in a short period of time as much as the gas carburizing method, and can produce products with stable quality. That is, the present invention embeds sintered iron in a mixed powder in which a carburizing agent powder mainly composed of carbon is blended with a refractory powder that does not substantially change under carburizing treatment conditions, and
The present invention relates to a carburizing method for sintered iron members, which is characterized by carrying out carburizing treatment in a heating furnace with an atmosphere of gas containing ~90% carbon monoxide. The carburizing reaction of the carburizing method of the present invention occurs as the following two chemical reactions proceed simultaneously in the right direction. In order to further increase the rate at which the reactions of equations (1) and (2) proceed in the right direction, it is necessary to increase the supply of carbon monoxide and to cause the reaction between carbon dioxide and carbon to occur quickly. The present invention satisfies all of these points. In the present invention, a mixed powder is used in which a refractory powder is blended with a carburizing agent powder mainly composed of carbon. The carburizing agent powder used in this case can be the same as that used in the solid carburizing method (for example, a mixture of coconut shell charcoal, carbon black, etc. with a carburizing accelerator such as barium carbonate). However, as for the particle size of the powder, it is preferable to use a fine powder under a 200-mesh sieve because the smaller the particle size, the larger the specific surface area of the powder and the faster it reacts with the atmospheric gas, increasing the carburizing ability. Further, as the refractory powder, a wide range of materials that do not substantially change under carburizing conditions can be used, such as alumina, magnesia, silica, zircon sand, or mixtures or compounds thereof. The particle size of the refractory powder is preferably below a 20 mesh sieve, in order to increase the air permeability of the mixed powder with the carburizing agent powder, allow atmospheric gas to penetrate easily, and fully demonstrate the carburizing effect. Particularly preferred is a sieve of lower to 80 mesh. Such refractory powder disperses carburizing agent powder to prevent mutual adhesion and effectively exhibit carburizing ability. It also has the effect of equalizing the heating during processing. The blending ratio of refractory powder and carburizing agent powder is not particularly limited and can be appropriately selected within a wide range depending on the application, but from the viewpoint of carburizing ability, economical efficiency, workability, etc. The content is preferably 6% to 24% by weight, particularly preferably 6 to 24% by weight. The atmospheric gas in the present invention is 2 to 90%
Hydrocarbon modified gas such as methane, propane, butane, city gas, etc. containing carbon monoxide within the range of 20 to 30% can be used. If the carbon monoxide content is less than 2%, the absolute amount of carbon monoxide is small, making it difficult for the carburizing reaction to proceed and it is not economical. If it is more than 90%, the carbon monoxide decomposes and produces soot, resulting in poor workability. The atmospheric gas is selected as appropriate depending on the application, since the degree of carburization varies depending on the composition of the gas used. Carburizing temperature and treatment time are selected appropriately depending on the type, size, number, etc. of sintered iron, but usually 800 to 1000
°C for 15 minutes to 2 hours. After carburizing, it is quenched and hardened according to a conventional method. In conventional gas carburizing processing, the composition ratio of the atmospheric gas fluctuates somewhat during use, resulting in a decrease in carburizing ability or excessive carburizing, which can lead to unstable quality. Ta. However, in the carburizing method of the present invention, even if the composition ratio of the atmospheric gas changes slightly, the carburizing ability can be adjusted to a considerable extent by the reaction between the carburizing agent and the atmospheric gas around the carburizing agent, so it is different from the conventional gas carburizing method. Compared to the case of treatment, the degree of carburization is constant and the quality is stable. The carburizing method of the present invention may seem like a solid carburizing method at first glance, but it is actually closer to a gas carburizing method, and its carburizing reaction is faster and more effective than that of the gas carburizing method. The carburizing method of the present invention does not require particularly advanced technology or skill when setting carburizing treatment conditions, and can be carried out easily and stably, so it is suitable for carburizing not only mass-produced products but also a wide variety of small-volume products. ing. Incidentally, the mixed powder for carburizing treatment can be used repeatedly, but since the carbon content gradually decreases, it is desirable to occasionally replenish and add carbon to stabilize the carburizing ability. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. The sintered iron used here was manufactured by the following method. Nickel powder: Average particle size 5 μm Carbon (graphite powder): Average particle size 10 μm Molybdenum powder: Average particle size 1 μm Iron powder: Particle size 100 mesh or less Add 1 part zinc stearate powder as a lubricant to 100 parts of a suitable blend of the above powders. After molding at a pressure of 6 ton/cm 2 , each sintered iron was obtained by heating and sintering at 1180° C. for 1 hour in decomposed ammonia gas. Example 1 Composition: 2% nickel, 0.2% carbon, balance iron,
Density: 7.0g/cm 3 , dimensions: φ11.3 x 15mm cylindrical sintered iron, alumina powder (particle size approx. 60 mesh) and carbon black powder (particle size 200 mesh under sieve)
7% and barium carbonate powder (particle size 200 mesh sieved) 3% mixed powder was buried in a steel plate container, and the container was filled with propane modified gas (gas composition CO≒24%, H 2 ≒32%). , N 2 ≒44%), and was placed in a furnace heated to 880°C, and carburized for 90 minutes. The obtained carburized sintered iron is
Fill again with propane converted gas (gas composition same as above)
A steel plate container was placed in a furnace heated to 850°C, heated for 60 minutes, and then quenched in turbine oil (140#). Furthermore, the obtained quenched product is filled with nitrogen gas.
It was placed in a steel plate melter in a furnace heated to 200°C, tempered for 60 minutes, and then cooled in air. The surface macro hardness (Rockwell A scale) and the micro hardness of the cross section of the sample (microbits 100 g/15 sec) were measured for the obtained carburized and quenched sintered iron.
Table 1 shows the results of examining the degree of carburization or degree of quench hardening. Comparative Example 1 For comparison, the same sintered iron as in Example 1 was subjected to conventional gas carburizing and quenching treatment (Example 1 was used as the atmospheric gas).
The one used in the above was used with 3% propane added. Table 1 shows the results of carburizing at 880°C for 90 minutes, cooling to 850°C, quenching in oil, and tempering at 200°C for 60 minutes. Example 2 Composition: 4% nickel, 0.5% molybdenum, 0.2%
Carbon, balance iron, density: 7.0 g/cm 3 , dimensions: φ11.3 x 15 mm cylindrical sintered iron, alumina powder (particle size approx. 60 mesh), carbon black powder (particle size 200 mesh under sieve) 4% and carbonic acid The container was buried in a steel plate container containing a mixed powder containing 2% of barium powder (particle size 200 mesh sieved), and the container was filled with propane-modified gas (composition 24% CO, 32% H 2 , 44%
%N 2 ) in a furnace heated to 880° C. and carburized for 60 minutes. The obtained carburized sintered iron was quenched and tempered in the same manner as in Example 1. Table 1 shows the results of macro hardness and micro hardness measurements. Comparative Example 2 For comparison, the same sintered iron as in Example 2 was subjected to conventional gas carburizing and quenching (the atmospheric gas used in Example 1 plus 3% propane was used. Carburizing treatment at 880°C Table 1 shows the results when the specimen was cooled to 850°C for 60min, then quenched in oil and tempered at 200°C for 60min.
【表】
実施例 ３
組成：100％鉄、密度：6.8ｇ／cm3、寸法形状：
φ11.3×15mm円柱の焼結鉄をアルミナ粉末（粒度
約60メツシユ）にカーボンブラツク粉末（粒度
200メツシユ篩下）15％及び炭酸バリウム粒末
（粒度200メツシユ篩下）５％を配合した混合粉末
を入れた鋼板製容器内に埋没せしめ、該容器をプ
ロパン変成ガス（24％CO、32％H2、44％N2）の
存在下850℃に加熱した炉内に配置して90分間浸
炭処理を行つた。得られた浸炭処理焼結鉄につい
てその試料断面の顕微鏡組織写真（倍率×200）
を第１図に示す。Ａは試料表面を示す。第１図よ
り均一に浸炭されていることが判る。
比較例 ３
比較のため実施例３と同一の焼結鉄をプロパン
変成ガス（組成同上）の存在下850℃に加熱した
炉内に浸炭処理剤なしで鋼板製容器に入れて配置
して90分間加熱したものについてその試料断面の
顕微鏡組織写真（倍率×200）を第２図に示す。
Ａは試料表面を示す。第２図より殆んど浸炭され
ていないことが判る。
以上の結果から、本発明の浸炭法は簡便な操作
にして従来のガス浸炭法と同等乃至それ以上のす
ぐれた浸炭性能を示すことがわかる。[Table] Example 3 Composition: 100% iron, density: 6.8g/cm 3 , dimensions and shape:
A φ11.3 x 15 mm cylinder of sintered iron is mixed with alumina powder (particle size approx. 60 mesh) and carbon black powder (particle size
The container was buried in a steel plate container containing a mixed powder containing 15% of barium carbonate powder (particle size of 200 mesh) and 5% of barium carbonate powder (particle size of 200 mesh), and the container was filled with propane converted gas (24% CO, 32% It was placed in a furnace heated to 850° C. in the presence of H 2 , 44% N 2 ) and carburized for 90 minutes. Microscopic micrograph of a cross section of the obtained carburized sintered iron (magnification x 200)
is shown in Figure 1. A indicates the sample surface. It can be seen from Figure 1 that the carburization was uniform. Comparative Example 3 For comparison, the same sintered iron as in Example 3 was placed in a steel plate container without a carburizing agent in a furnace heated to 850°C in the presence of propane converted gas (composition as above) for 90 minutes. Figure 2 shows a microscopic microstructure photograph (magnification x 200) of a cross section of the heated sample.
A indicates the sample surface. From Figure 2, it can be seen that there is almost no carburization. From the above results, it can be seen that the carburizing method of the present invention is easy to operate and exhibits excellent carburizing performance equivalent to or better than the conventional gas carburizing method.
第１図は浸炭処理焼結鉄（実施例３）の断面の
顕微鏡組織写真（倍率×200）を示す。第２図は
浸炭処理剤無しで浸炭処理した焼結鉄（比較例
３）の断面の顕微鏡組織写真（倍率×200）を示
す。Ａはいずれの場合も試料表面を示す。
FIG. 1 shows a micrograph (magnification: x200) of a cross section of carburized sintered iron (Example 3). FIG. 2 shows a micrograph (magnification: x200) of a cross section of sintered iron (Comparative Example 3) that was carburized without a carburizing agent. A indicates the sample surface in both cases.
Claims (1)
粉末に炭素を主体とした浸炭剤粉末を配合した混
合粉末に焼結鉄を埋没せしめ、２〜90％の一酸化
炭素を含むガスを雰囲気とする加熱炉内に於いて
浸炭処理を行なうことを特徴とする焼結鉄部材の
浸炭法。1. Sintered iron is buried in a mixed powder made of a refractory powder that does not substantially change under carburizing conditions and a carburizing agent powder mainly composed of carbon, and a gas containing 2 to 90% carbon monoxide is placed in the atmosphere. A carburizing method for sintered iron members, characterized by carrying out carburizing treatment in a heating furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18194881A JPS5884967A (en) | 1981-11-12 | 1981-11-12 | Carburizing method for sintered iron member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18194881A JPS5884967A (en) | 1981-11-12 | 1981-11-12 | Carburizing method for sintered iron member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5884967A JPS5884967A (en) | 1983-05-21 |
| JPS6330395B2 true JPS6330395B2 (en) | 1988-06-17 |
Family
ID=16109673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18194881A Granted JPS5884967A (en) | 1981-11-12 | 1981-11-12 | Carburizing method for sintered iron member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5884967A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003073796A (en) * | 2001-09-03 | 2003-03-12 | Fuji Oozx Inc | Surface treatment method for titanium-based material |
| JP2008266762A (en) * | 2007-04-25 | 2008-11-06 | Aisin Seiki Co Ltd | Method for manufacturing metal material including carburizing treatment process |
| JP6321982B2 (en) * | 2014-02-06 | 2018-05-09 | 国立大学法人 熊本大学 | Method for surface treatment of metal material |
-
1981
- 1981-11-12 JP JP18194881A patent/JPS5884967A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5884967A (en) | 1983-05-21 |
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