JPH0447006B2 - - Google Patents
Info
- Publication number
- JPH0447006B2 JPH0447006B2 JP24911583A JP24911583A JPH0447006B2 JP H0447006 B2 JPH0447006 B2 JP H0447006B2 JP 24911583 A JP24911583 A JP 24911583A JP 24911583 A JP24911583 A JP 24911583A JP H0447006 B2 JPH0447006 B2 JP H0447006B2
- Authority
- JP
- Japan
- Prior art keywords
- carbide
- cast iron
- graphite
- forming element
- element powder
- 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
- 238000000034 method Methods 0.000 claims description 33
- 239000000843 powder Substances 0.000 claims description 33
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 28
- 229910001018 Cast iron Inorganic materials 0.000 claims description 23
- 229910002804 graphite Inorganic materials 0.000 claims description 23
- 239000010439 graphite Substances 0.000 claims description 23
- 239000011230 binding agent Substances 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 7
- 239000000155 melt Substances 0.000 claims 1
- 239000000463 material Substances 0.000 description 23
- 230000000694 effects Effects 0.000 description 8
- 238000002844 melting Methods 0.000 description 8
- 230000008018 melting Effects 0.000 description 8
- 239000011347 resin Substances 0.000 description 7
- 229920005989 resin Polymers 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 230000007547 defect Effects 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 239000011812 mixed powder Substances 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 239000004925 Acrylic resin Substances 0.000 description 3
- 229920000178 Acrylic resin Polymers 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- UNASZPQZIFZUSI-UHFFFAOYSA-N methylidyneniobium Chemical compound [Nb]#C UNASZPQZIFZUSI-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000005480 shot peening Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D5/00—Heat treatments of cast-iron
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Description
（産業上の利用分野）
本発明は、鋳鉄部材の表面部にチル層を形成す
ることにより該表面部の硬度を高めてその耐摩耗
性の向上を図るようにした鋳鉄部材の表面硬化方
法に関するものである。
（従来技術）
この種の鋳鉄部材の表面硬化方法としては種々
の方法が知られており、例えば鋳鉄部材の表面に
溶融樹脂等のバインダと炭化物生成元素粉末との
混合液を塗布したのち、バインダを一部除去して
電子ビーム等を用いて溶融チル化処理を施し、該
表面部にチル層を形成する方法がある。
ところが、この公知方法によれば、
(1) 炭化物生成元素粉末が母材表面上に塗布され
ているため該炭化物生成元素粉末の母材内部へ
の拡散状態が悪く、その結果、形成されるチル
層が不均一な組織になり易い、
(2) レーザビーム等を用いて溶融チル化処理を行
なう際、保護ガスの噴流によつて炭化物生成元
素粉末が飛散するのを防止する必要上からバイ
ンダを完全に取り除くことができず、このた
め、バインダの焼成時に発生するガスによりチ
ル層内に気泡が発生し、その強度が低下する、
等の問題がある。
なお、鋳鉄を酸化処理して形成した鋳鉄のポー
ラス部に低融点金属を含浸するものは、特開昭49
−65316号公報で知られている。
（発明の目的）
本発明は、上記の如き従来の表面硬化方法の問
題に鑑み、ガス欠陥が少なく致密で均一な組織を
もつたチル層が形成でき、しかも炭化物生成元素
粉末の歩留りも良好な鋳鉄部材の表面硬化方法を
提案することを目的としてなされたものである。
（発明の構成）
本発明の鋳鉄部材の面硬化方法は、鋳鉄で形成
された鋳鉄部材の表面に、大気加熱法等による脱
黒鉛処理を施して該表面上に露出している黒鉛を
適度に除去し、しかる後、該表面上に有機系バイ
ンダに混合した炭化物生成元素粉末を塗布してこ
れをすり込み処理により前記黒鉛除去後の凹穴内
にすり込み、その後該凹穴内にすり込まれたバイ
ンダを焼失させて除去したのち前記表面部にレー
ザビーム等の熱源を用いて溶融チル化処理を施し
て該表面部にチル層を形成することを特徴として
いる。
さらに本発明の鋳鉄部材の表面硬化方法を詳し
く説明すると、本発明の表面硬化方法は、先ず第
１図Ａに示す如く表面１ａ上に黒鉛（片状黒鉛で
も球状黒鉛でもよい）２，２……を露出させた鋳
造製の母材１を用意し、この母材１に大気加熱法
等により脱黒鉛処理を施して第１図Ｂに示す如く
該表面１ａ上に除去黒鉛跡による凹穴３，３……
を多数形成する。次に、この母材表面１ａ上に残
つた凹穴３，３……内に、炭化物生成元素粉末と
バインダの混合液をすり込み、その後、該バイン
ダを除去（焼失）して該凹穴３，３……内に炭化
物生成元素粉末４を残留させる（第１図Ｃ）。
次に、この母材１の表面部分に電子ビームある
いはレーザビーム等の熱源を用いて溶融チル化処
理を施し、第１図Ｄに示す如く表面部分にチル層
５を形成するものである。
尚、大気加熱法による脱黒鉛処理は、母材１を
加熱炉にて大気中で600℃〜950℃に加熱し、母材
１の表面に露出している黒鉛２，２……を酸化さ
せて除去するものである。この黒鉛の除去深さ
は、処理時間が長くなるほど深くなる。従つて、
処理時間は、必要なチル層の厚さに応じて適宜に
設定してやる必要がある。又、処理温度は、600
℃以下になると脱炭速度が鈍り黒鉛が除去されに
くくなり、また950℃以上になると母材表面の酸
化スケールの生成が増長され表面に厚い酸化膜が
できて内部の黒鉛が除去されにくくなるところか
ら上記の如く600℃〜950℃とするのが望ましい。
又、炭化物生成元素粉末としては例えば、ほう
素(B)、炭素(c)、パナジウム(v)、クロム（Cr）、マ
ンガン（Mn）、コバルト（Co）、ニツケル（Ni）、
ニオブ（Nb）、モリブデン（Mo）、タンタル
（Ta）、タングステン(W)等の元素粉末あるいはこ
れらの金属元素を２種類以上含む合金粉末とか炭
化タングステン（Wc）、炭化ニオブ（NbC）等
の炭化物が採用可能であり、実際に使用する場合
は、２種類以上の混合粉末とされる。又、粉末の
粒度は黒鉛除去穴へのすり込み性を良好ならしめ
る意味から200メツシユ以下が適当であり、さら
に粉末に硬度としては、粉末の塑性変形によるす
り込み性の悪化を防止するという点から鋳鉄素地
より少なくとも高い硬度を有する必要があり、通
常Hv250以上の硬度を有していることが望まし
い。
又、バインダとしては、下記第１表に示した樹
脂等が適用可能である。
(Industrial Application Field) The present invention relates to a method for hardening the surface of a cast iron member, in which a chill layer is formed on the surface of the cast iron member to increase the hardness of the surface and improve the wear resistance of the cast iron member. It is something. (Prior Art) Various methods are known for surface hardening of this type of cast iron member. For example, after applying a liquid mixture of a binder such as a molten resin and carbide-forming element powder to the surface of the cast iron member, the binder is hardened. There is a method in which a portion of the material is removed and a chilled layer is formed on the surface by melting and chilling using an electron beam or the like. However, according to this known method, (1) since the carbide-forming element powder is coated on the surface of the base material, the diffusion state of the carbide-forming element powder into the base material is poor, and as a result, the formed chill (2) When melting and chilling using a laser beam, it is necessary to prevent the carbide-forming element powder from scattering due to a jet of protective gas. It cannot be completely removed, and as a result, there are problems such as bubbles being generated in the chill layer due to the gas generated when the binder is fired, reducing its strength. In addition, a method of impregnating a low melting point metal into the porous part of cast iron formed by oxidizing cast iron is disclosed in Japanese Patent Application Laid-open No. 49
It is known from the publication No.-65316. (Object of the Invention) In view of the problems of the conventional surface hardening method as described above, the present invention has been developed to form a chilled layer having a close and uniform structure with few gas defects, and also to provide a good yield of carbide-forming element powder. The purpose of this work was to propose a surface hardening method for cast iron members. (Structure of the Invention) The surface hardening method for a cast iron member of the present invention involves degraphitizing the surface of a cast iron member formed of cast iron by atmospheric heating or the like to moderately remove graphite exposed on the surface. After that, a carbide-forming element powder mixed with an organic binder is applied onto the surface, and this is rubbed into the recessed hole after the graphite has been removed by a rubbing process, and then rubbed into the recessed hole. The method is characterized in that after the binder is burned out and removed, the surface portion is subjected to a melting and chilling treatment using a heat source such as a laser beam to form a chill layer on the surface portion. Further, to explain in detail the surface hardening method of a cast iron member of the present invention, first, as shown in FIG. 1A, graphite (flake graphite or spheroidal graphite) 2, 2... A cast base material 1 with exposed ... is prepared, and this base material 1 is degraphitized by atmospheric heating or the like, and as shown in FIG. ,3...
form a large number of Next, a mixed liquid of carbide-forming element powder and a binder is rubbed into the recessed holes 3, 3... remaining on the base material surface 1a, and then the binder is removed (burned out) and , 3 . . . to leave the carbide-forming element powder 4 (FIG. 1C). Next, the surface portion of the base material 1 is melted and chilled using a heat source such as an electron beam or a laser beam to form a chilled layer 5 on the surface portion as shown in FIG. 1D. In addition, the degraphitization treatment by the atmospheric heating method involves heating the base material 1 in a heating furnace to 600°C to 950°C in the atmosphere to oxidize the graphite 2, 2... exposed on the surface of the base material 1. It is to be removed. The depth of graphite removal becomes deeper as the treatment time becomes longer. Therefore,
The processing time needs to be appropriately set depending on the required thickness of the chill layer. In addition, the processing temperature is 600
When the temperature is below ℃, the decarburization rate slows down and it becomes difficult to remove graphite, and when the temperature exceeds 950℃, the formation of oxide scale on the surface of the base material increases and a thick oxide film is formed on the surface, making it difficult to remove the graphite inside. Therefore, as mentioned above, it is desirable to set the temperature to 600°C to 950°C. Examples of carbide-forming element powders include boron (B), carbon (c), panadium (v), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni),
Elemental powders such as niobium (Nb), molybdenum (Mo), tantalum (Ta), and tungsten (W), or alloy powders containing two or more of these metal elements, and carbides such as tungsten carbide (Wc) and niobium carbide (NbC). can be adopted, and when actually used, a mixed powder of two or more types is used. In addition, the particle size of the powder is preferably 200 mesh or less in order to make it easy to slip into the graphite removal hole, and the hardness of the powder is also important to prevent deterioration of the slipability due to plastic deformation of the powder. Therefore, it is necessary to have a hardness that is at least higher than that of the cast iron base, and it is usually desirable to have a hardness of Hv250 or higher. Further, as the binder, resins shown in Table 1 below can be used.
【表】
さらに、この樹脂（バインダ）と炭化物生成元
素粉末との配合比率は、樹脂５〜20体積％に対し
て炭化物生成元素粉末80〜95体積％とするのが望
ましい。即ち、樹脂量が５体積％以下になると母
材１と炭化物生成元素粉末との結合性が低下して
凹穴３へのすり込み（充填）が困難となり、逆に
樹脂量が20体積％以上になると凹穴３内にすり込
まれる炭化物生成元素粉末の絶体量が減少しその
効果がうすれる。尚、溶剤の添加量は、樹脂と炭
化物生成元素粉末の配合比率に応じて適宜に設定
する。また、すり込み処理の圧力としては1.0
Kg／cm2以上が好ましい。
上述の如くして形成されたチル層５は、後述す
る如くガス欠陥が少なく、しかも緻密で均一な組
織を有し、従つて耐摩耗性に優れているものであ
るが以下、これを下記する実施例及び該実施例に
対する耐摩耗性試験結果等から論証することにす
る。
（実施例）
先ず、炭素3.5％、けい素4.0％、マンガン0.5
％、リン0.05％、硫黄0.06％、鉄91.89％の成分を
もつ材料を鋳造及び機械加工して30mm×50mm×20
mmの試験片を得る。この試験片の黒鉛形態は片状
黒鉛である。
次に、この試験片に対して、シヨツトの材質を
アルミナサイド（粒度150）、ガラスビーズ（粒度
80）とし、噴射圧力Ｐ＝1.0〜3.0Kg／cm2、シヨツ
ト角度90゜の条件の下でシヨツトピーニングを行
なう。
次に、この試験片に対して大気加熱法により黒
鉛除去処理を行なう。即ち、電気炉を用いて試験
片を大気中で800℃に２時間加熱した後、これを
大気中で放冷する（第１図Ｂ参照）。
次に、アクリル樹脂（バインダ）と、鉄とほう
素と炭素を鉄95.5％、ほう素1.5％、炭素３％配
合比率で混合した混合粉末と、アセトン（溶剤）
とをアクリル樹脂７体積％、混合粉末93体積％
（アセトンは適当量）の配合比率で混合してなる
塗布液を用意し、これを試験片の表面にはけ塗り
（スプレー方式でもよい）で塗布した後、約10分
間自然乾燥させて溶剤を拡散させる。
次に、試験片の表面上に塗布された上記塗布液
を、ラバー砥石を用いて2.0Kg／cm2の圧力で該表
面上の黒鉛除去跡（凹穴）内にすり込み（すり込
み処理）、その後、該試験片を300℃で一時間加熱
して該凹穴内にすり込まれた塗布液中のアクリル
樹脂を焼失させて（バインダの除去）、該凹穴内
に混合粉末（即ち、炭化物生成元素粉末）を残留
させる（第１図Ｃ参照）。
次に、熱源としてレーザビームを用いて試験片
の前記混合粉末がすり込まれた表面に溶融チル化
処理を施して該表面部分にチル層を形成した（第
１図Ｄ参照）。尚、この溶融チル化処理の処理条
件としては、ビーム出力……3KW、レンズ径…
…５インチ、ab値……１，２、加工速度……
0.55m／min、アシストガス……N2、ビームモー
ド……シングルモードとした。
上記製造工程に従つて表面硬化処理を行なつた
試験片の組織写真（倍率×100）を第３図に示し
ている。この第３図の組織写真において白く写つ
ている部分（試験片表面１ａから深さＸの範囲）
がチル層であり、また該チル層の内側（深部側）
に位置する黒い部分（符号Ｙの部分）はチル化さ
れていない素材組織部分である。この第３図から
は、このチル層はガス欠陥もなくしかも緻密で均
一な組織であることがわかる。
さらに、本発明の表面硬化方法による表面硬化
効果（耐摩耗性効果）を調べるために、本発明の
表面硬化方法によつて処理が行なわれた上記試験
片（試験片Ａという）と、本発明の表面硬化方法
以外の方法によつて表面硬化処理が行なわれた２
つの試験片即ち、脱黒鉛処理を行なつていない試
験片の表面に試験片Ａに使用した塗布液を塗布し
た後、レーザビームを使用して溶融チル化処理を
施した試験片Ｂと、脱黒鉛処理を行なつていない
試験片の表面に塗布液を塗布することなくそのま
まレーザビームを使用して溶融チル化処理を施し
た試験片ｃの合計３個の試験片を用意し、これら
３個の試験片のチル層を形成した表面の硬度を調
べ、その結果を第２図に示したが、この試験結果
から、本発明の表面硬化方法によつて表面処理を
行なつた試験片Ａの表面硬度が他の方法によつて
表面処理を行なつた試験片Ｂ及び試験片Ｃに較べ
て高く、十分な表面硬化効果があつたことがわか
る。ここのように、本発明の表面硬化方法によつ
て形成されたチル層はガス欠陥がほとんどなくし
かも緻密で均一な組織とされ従つてその硬度（耐
摩耗性）も高いわけであるが、これは素材表面の
黒鉛を除去して該表面上に残つた凹欠内に炭化物
生成元素粉末をすり込むようにしたことによるも
のである。即ち、ガス欠陥の少ないチル層が得ら
れるのは、素材表面上の凹穴内に炭化物生成元素
粉末とバインダの混合液をすり込むようにしてい
るため、該素材表面部にレーザビームを使用して
溶融チル化処理を施す場合に酸化防止用の保護ガ
スによつて炭化物生成元素粉末が飛散されるとい
うおそれが少なく、それだけバインダの除去率を
向上させる、換言すれば凹穴内に残留するバイン
ダ量を可及的に減少させることが可能であり、後
工程の溶融チル化処理時にバインダの焼成によつ
て発生するガスが可及的に少なくなるためであ
る。
又、緻密で且つ均一なチル層が得られるのは、
炭化物生成元素粉末が、素材表面上でなく該素材
表面に形成された凹穴内にすり込まれているため
（換言すれば、炭化物生成元素粉末が素材の深部
に存在しているため）、該素材表面部に溶融チル
化処理を行なつた場合に該炭化物生成元素粉末の
の拡散が促進されるためである。
尚、上記実施例においては、第１図Ｂに示す如
く素材表面に露出する黒鉛を部分的に除去して凹
穴の底部に若干量黒鉛を残すようにしているが、
（炭化物生成作用を促進させるため）、本発明の他
の実施例においては素材表面に露出する黒鉛を全
て除去するようにしてもよい。
また、脱黒鉛処理は水酸化ナトリウム水溶液に
鋳鉄部材を浸漬して行う電解法であつてもよい。
（発明の効果）
本発明の鋳鉄部材の表面硬化方法によれば、鋳
鉄部材の表面に露出している黒鉛を除去してその
あとに残つた凹穴内に炭化物生成元素粉末を充填
するものであるため、該鋳鉄部材の表面にガス欠
陥が少なくしかも緻密で均一な組織をもつたチル
層を形成することができ、鋳鉄部部材の耐摩耗性
が向上するという効果がある。
さらに、鋳鉄部材の表面に残つた黒鉛除去後の
凹穴内に炭化物生成元素粉末を充填した状態でレ
ーザビーム等の熱源を使用して溶融チル化処理を
施すものであるため、素材表面に炭化物生成元素
粉末を塗布したままの状態で溶融チル化処理を施
す従来方法の場合の如く溶融チル化処理時に炭化
物生成元素粉末が多量に飛散するというようなこ
とがなく、それだけ炭化物生成元素粉末の歩留り
が向上し、コストダウンを図り得るという効果も
ある。[Table] Further, the blending ratio of the resin (binder) and the carbide-forming element powder is preferably 80 to 95 volume % of the carbide-forming element powder to 5 to 20 volume % of the resin. That is, when the resin amount is less than 5% by volume, the bonding property between the base material 1 and the carbide-forming element powder decreases, making it difficult to insert (fill) into the recessed hole 3. Conversely, when the resin amount is 20% by volume or more, When this happens, the absolute amount of carbide-forming element powder that is rubbed into the recessed hole 3 decreases, and its effect is diminished. Incidentally, the amount of the solvent added is appropriately set depending on the blending ratio of the resin and the carbide-forming element powder. Also, the pressure for the rubbing process is 1.0
Kg/cm 2 or more is preferable. The chill layer 5 formed as described above has few gas defects as described later, has a dense and uniform structure, and therefore has excellent wear resistance, which will be described below. This will be demonstrated from Examples and the results of wear resistance tests for the Examples. (Example) First, carbon 3.5%, silicon 4.0%, manganese 0.5
%, 0.05% phosphorus, 0.06% sulfur, and 91.89% iron are cast and machined into 30mm x 50mm x 20
Obtain a mm test piece. The graphite form of this test piece is flake graphite. Next, for this test piece, the shot material was changed to alumina side (grain size 150) and glass beads (grain size 150).
80), shot peening is performed under the conditions of injection pressure P = 1.0 to 3.0 Kg/cm 2 and shot angle of 90°. Next, graphite removal treatment is performed on this test piece by an atmospheric heating method. That is, the test piece was heated in the atmosphere to 800° C. for 2 hours using an electric furnace, and then allowed to cool in the atmosphere (see FIG. 1B). Next, acrylic resin (binder), mixed powder made by mixing iron, boron, and carbon with a mixing ratio of 95.5% iron, 1.5% boron, and 3% carbon, and acetone (solvent)
Acrylic resin 7% by volume, mixed powder 93% by volume
(appropriate amount of acetone) is prepared, and this is applied to the surface of the test piece by brushing (a spray method is also acceptable), and then air-dried for about 10 minutes to remove the solvent. Spread it. Next, the above coating liquid applied to the surface of the test piece is rubbed into the graphite removal marks (concave holes) on the surface using a rubber grindstone at a pressure of 2.0 kg/cm 2 (rubbing treatment). Thereafter, the test piece was heated at 300°C for one hour to burn off the acrylic resin in the coating solution rubbed into the recessed hole (removal of binder), and the mixed powder (i.e., carbide formation) was deposited in the recessed hole. elemental powder) (see Figure 1C). Next, using a laser beam as a heat source, the surface of the test piece into which the mixed powder was rubbed was melted and chilled to form a chilled layer on the surface (see FIG. 1D). The processing conditions for this melting and chilling treatment are: beam output...3KW, lens diameter...
...5 inches, ab value...1, 2, machining speed...
0.55m/min, assist gas... N2 , beam mode...single mode. FIG. 3 shows a photograph (magnification: x100) of the structure of a test piece subjected to surface hardening treatment according to the above manufacturing process. The white part in the microstructure photograph in Figure 3 (range of depth X from the specimen surface 1a)
is the chill layer, and the inside (deep side) of the chill layer
The black part (the part marked Y) located in is the part of the material structure that has not been chilled. It can be seen from FIG. 3 that this chill layer has no gas defects and has a dense and uniform structure. Furthermore, in order to investigate the surface hardening effect (wear resistance effect) by the surface hardening method of the present invention, the above test piece (referred to as test piece A) treated by the surface hardening method of the present invention and the present invention Surface hardening treatment was performed by a method other than the surface hardening method of 2.
After applying the coating liquid used for test piece A on the surface of two test pieces, that is, a test piece that has not been subjected to degraphitization treatment, test piece B was subjected to melting and chilling treatment using a laser beam, and A total of three test pieces (c), which were subjected to melting and chilling treatment using a laser beam without applying a coating liquid to the surface of a test piece that had not been subjected to graphite treatment, were prepared, and these three The hardness of the surface of the test piece A on which the chill layer was formed was investigated, and the results are shown in Figure 2.From this test result, the hardness of the test piece A, which had been surface-treated by the surface hardening method of the present invention, was determined. It can be seen that the surface hardness was higher than that of Test Pieces B and C, which were surface-treated by other methods, and that a sufficient surface hardening effect was achieved. As shown here, the chill layer formed by the surface hardening method of the present invention has almost no gas defects, has a dense and uniform structure, and has high hardness (wear resistance). This is because graphite on the surface of the material is removed and carbide-forming element powder is rubbed into the depressions remaining on the surface. In other words, a chilled layer with few gas defects can be obtained by rubbing the mixture of carbide-forming element powder and binder into the concave holes on the surface of the material, which is then melted using a laser beam on the surface of the material. When performing chilling treatment, there is less risk of the carbide-forming element powder being scattered by the protective gas for oxidation prevention, which improves the binder removal rate.In other words, the amount of binder remaining in the recessed hole can be reduced. This is because the amount of gas generated by firing the binder during the melt-chilling process in the subsequent process is reduced as much as possible. In addition, a dense and uniform chill layer can be obtained by
Because the carbide-forming element powder is rubbed into the concave hole formed on the material surface rather than on the material surface (in other words, because the carbide-forming element powder is present deep within the material), the material This is because when the surface portion is subjected to melt-chilling treatment, the diffusion of the carbide-forming element powder is promoted. In the above embodiment, as shown in FIG. 1B, the graphite exposed on the surface of the material is partially removed to leave a small amount of graphite at the bottom of the recessed hole.
In other embodiments of the present invention, all graphite exposed on the surface of the material may be removed (to promote the carbide generation effect). Further, the degraphitizing treatment may be an electrolytic method performed by immersing the cast iron member in an aqueous sodium hydroxide solution. (Effects of the Invention) According to the surface hardening method for cast iron members of the present invention, the graphite exposed on the surface of the cast iron member is removed and the recesses remaining after that are filled with carbide-forming element powder. Therefore, a chill layer with few gas defects and a dense and uniform structure can be formed on the surface of the cast iron member, which has the effect of improving the wear resistance of the cast iron member. Furthermore, since the recessed hole after removing the graphite remaining on the surface of the cast iron member is filled with carbide-forming element powder, a heat source such as a laser beam is used to perform the melting and chilling treatment, which prevents the formation of carbide on the surface of the material. Unlike the conventional method in which the element powder is melted and chilled while it is applied, a large amount of carbide-forming element powder is not scattered during the melt-chilling process, and the yield of carbide-forming element powder is increased accordingly. It also has the effect of improving performance and reducing costs.
第１図各図は本発明の表面硬化方法によつて表
面処理を行なう場合の処理進行状態図、第２図は
表面硬度試験の試験結果を示す線図、第３図は本
発明の表面硬化方法によつて形成されたチル層の
組織写真である。
１……鋳鉄部材、２……黒鉛、３……凹穴、４
……炭化物生成元素粉末、５……チル層。
Figure 1 shows the progress of the surface treatment when surface hardening is carried out by the surface hardening method of the present invention, Figure 2 is a diagram showing the test results of the surface hardness test, and Figure 3 is the surface hardening method of the present invention. 1 is a photograph of the structure of a chilled layer formed by the method. 1... Cast iron member, 2... Graphite, 3... Recessed hole, 4
... Carbide-forming element powder, 5... Chill layer.
Claims (1)
熱法等による脱黒鉛処理を施して該表面上に露出
している黒鉛を適度に除去し、しかる後、該表面
上に有機系バインダに混合した炭化物生成元素粉
末を塗布してこれをすり込み処理により前記黒鉛
除去後の凹穴内にすり込み、その後該凹穴内にす
り込まれたバインダを焼失させて除去したのち前
記表面部にレーザビーム等の熱源を用いて溶融チ
ル化処理を施して該表面部にチル層を形成するこ
とを特徴とする鋳鉄部材の表面硬化方法。1. The surface of a cast iron member made of cast iron is subjected to degraphitization treatment using an atmospheric heating method or the like to appropriately remove graphite exposed on the surface, and then mixed with an organic binder on the surface. The carbide-forming element powder is applied and rubbed into the recessed hole from which the graphite has been removed, and then the binder rubbed into the recessed hole is burned out and removed, and then a laser beam or the like is applied to the surface area. A method for hardening the surface of a cast iron member, the method comprising performing a melt chilling treatment using a heat source to form a chill layer on the surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24911583A JPS60135518A (en) | 1983-12-23 | 1983-12-23 | Surface hardening method of cast iron member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24911583A JPS60135518A (en) | 1983-12-23 | 1983-12-23 | Surface hardening method of cast iron member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60135518A JPS60135518A (en) | 1985-07-18 |
| JPH0447006B2 true JPH0447006B2 (en) | 1992-07-31 |
Family
ID=17188169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24911583A Granted JPS60135518A (en) | 1983-12-23 | 1983-12-23 | Surface hardening method of cast iron member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60135518A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60187660A (en) * | 1984-02-24 | 1985-09-25 | Honda Motor Co Ltd | Partially hardened cast iron parts |
| JPS62199779A (en) * | 1986-02-26 | 1987-09-03 | Haru Eng:Kk | Method for modifying metallic surface layer |
| CN107245713B (en) * | 2017-05-25 | 2019-02-26 | 中北大学 | Alloy powder for repairing ductile iron roll surface by laser cladding |
-
1983
- 1983-12-23 JP JP24911583A patent/JPS60135518A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60135518A (en) | 1985-07-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0480791B2 (en) | ||
| EP3631035A1 (en) | Method and system for improving the surface fracture toughness of brittle materials, and a cutting tool produced by such method | |
| UA75593C2 (en) | An alloy based on iron containing chrome-tungsten carbide, and a method for producing thereof | |
| KR101279840B1 (en) | Hardfacing ferroalloy materials | |
| JP4208426B2 (en) | Induction hardening method and bearing parts | |
| US9003681B2 (en) | Bucket teeth having a metallurgically bonded coating and methods of making bucket teeth | |
| KR950704526A (en) | ENGINEERING FERROUS METALS, IN PARTICULAR CAST IRON AND STEEL | |
| US3855015A (en) | Work roll for hot rolling | |
| KR910003481B1 (en) | Pig iron for the manufacture of brake bodies | |
| JPH0447006B2 (en) | ||
| JPH03115587A (en) | Production of remelted cam shaft | |
| EP0290052A1 (en) | Process for the fabrication of sliding surfaces of parts of motors for vehicles | |
| JP2000219931A (en) | Cemented carbide and its production | |
| RU2507027C1 (en) | Method of inductive hardening and reconditioning of parts | |
| JPH02145759A (en) | Method for carburizing steel | |
| KR102697911B1 (en) | Castings with hardened surface layer and manufacturing method for the same | |
| JP2774801B2 (en) | Rocker arm and method of manufacturing the same | |
| JPS62127460A (en) | Surface treatment | |
| US5096662A (en) | Method for forming high abrasion resisting layers on parent materials | |
| JPH01201459A (en) | High toughness wear-resistant parts | |
| EP0494977B1 (en) | Method of modifying the surface of a substrate | |
| JPH05179411A (en) | Surface modifying method for member made of aluminum alloy | |
| JPH0149784B2 (en) | ||
| JPH0518886B2 (en) | ||
| JPH06122137A (en) | Composite cylinder for plastic molding machine |