JPS6052514A - Manufacture of tough and hard gray cast iron - Google Patents

Manufacture of tough and hard gray cast iron

Info

Publication number
JPS6052514A
JPS6052514A JP16079683A JP16079683A JPS6052514A JP S6052514 A JPS6052514 A JP S6052514A JP 16079683 A JP16079683 A JP 16079683A JP 16079683 A JP16079683 A JP 16079683A JP S6052514 A JPS6052514 A JP S6052514A
Authority
JP
Japan
Prior art keywords
cast iron
gray cast
casting
mold
temp
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.)
Granted
Application number
JP16079683A
Other languages
Japanese (ja)
Other versions
JP2659353B2 (en
Inventor
Makoto Suenaga
末永　允
Mitsuru Yano
矢野　満
Yasuoki Ishihara
石原　安興
Kimiteru Otsuka
公輝 大塚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Proterial Ltd
Original Assignee
Hitachi Metals Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Metals Ltd filed Critical Hitachi Metals Ltd
Priority to JP58160796A priority Critical patent/JP2659353B2/en
Publication of JPS6052514A publication Critical patent/JPS6052514A/en
Application granted granted Critical
Publication of JP2659353B2 publication Critical patent/JP2659353B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
    • C21D1/20—Isothermal quenching, e.g. bainitic hardening
    • 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

Abstract

PURPOSE:To obtain a superior product in shortened working stages without adding expensive elements in large quantities by releasing a casting from the mold at a prescribed temp. above the A1 transformation range, and rapidly cooling the casting under specified conditions. CONSTITUTION:Molten metal having the composition of gray cast iron is charged into a casting mold and solidifed. The resulting casting is taken out of the mold at a prescribed temp. above the A1 transformation range, and it is rapidly cooled. At this time, the castig is rapidly cooled from said temp. at a cooling rate at which pearlitic transformation is not caused, and it is held at a temp. at which a mixed structure consisting of bainite and austenite is stably formed. After the lapse of a prescribed time, the casting is allowed to cool, or it is rapidly cooled. Thus, tough and hard gray cast iron having extremely superior machanical properties such as high strength and toughness is obtd.

Description

【発明の詳細な説明】 本発明は強靭ねずみ鋳鉄の製造法に係わり、特に鋳放し
状態で高強度、高靭性を有する強靭ねずみ鋳鉄の製造法
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing strong gray cast iron, and particularly to a method for manufacturing strong gray cast iron that has high strength and high toughness in an as-cast state.

ねずみ鋳鉄は基地中に片状黒鉛を有するため、鋳鉄の中
で最も大きな減衰能と熱導率を有するため、耐振動部材
あるいは快熱導性を要求される部材として、多用されて
いる。しかし、ねずみ鋳鉄は他の鋳鉄と比べてその引張
強さと靭性は、大きく劣る。Gray cast iron has flake graphite in its matrix, and has the highest damping capacity and thermal conductivity among cast irons, so it is often used as vibration-resistant members or members that require good thermal conductivity. However, gray cast iron is significantly inferior in tensile strength and toughness compared to other cast irons.

ねずみ鋳鉄において、パーライト地のものでその抗張力
は高々３０　ｋｇ／ｎｕｎ２程度であり、さらに高い抗
張力の材料を得るには基地をベイナイト組織とする必要
がある。強靭ねずみ鋳鉄を鋳放しの状態でベイナイト化
する方法はＭＯｌＮｉなどの高価な特殊元素を多量に添
加しなければならない。In gray cast iron, the tensile strength of pearlite base is about 30 kg/nun2 at most, and in order to obtain a material with even higher tensile strength, it is necessary to use a bainite structure as the base. The method of converting strong gray cast iron into bainite in its as-cast state requires the addition of a large amount of expensive special elements such as MOINi.

この方法は公知の事実であるが、きわめて不経済である
。Although this method is a known fact, it is extremely uneconomical.

本発明の目的は、Ｎｉ、Ｍｏなどの高価な元素を多量に
添加せずに、作業工程を短縮し且製造原価を低減し得る
高強度、高靭性の強靭ねずみ鋳鉄を製造する方法を提供
するにある。An object of the present invention is to provide a method for manufacturing strong gray cast iron with high strength and toughness, which can shorten the working process and reduce manufacturing costs without adding large amounts of expensive elements such as Ni and Mo. It is in.

本発明は、ねずみ鋳鉄組成を有する溶湯を鋳型に注湯し
凝固させた後、鋳造品をＡ１変態域以上のある所定の温
度で鋳型から取出し、急冷する強靭ねずみ鋳鉄の製造法
であって、上記Ａ１変態域以上の温度からパーライト変
態を生せしめない冷却速度で急冷し、ベイナイトとオー
ステナイトの混合組織を安定的に生せしめる温度に保持
し、所定時間経過後、放冷または急冷するものである。The present invention is a method for manufacturing strong gray cast iron, in which a molten metal having a gray cast iron composition is poured into a mold and solidified, and then the cast product is taken out of the mold at a predetermined temperature above the A1 transformation range and rapidly cooled. The product is rapidly cooled from a temperature above the A1 transformation range at a cooling rate that does not cause pearlite transformation, maintained at a temperature that stably produces a mixed structure of bainite and austenite, and allowed to cool or rapidly cool after a predetermined period of time has elapsed. .

以下本発明の実施例について詳細に説明する。Examples of the present invention will be described in detail below.

・ｋ案 実施例　１ （１）化学成分　（重量％） （２）テストピース　φ４０　’Ｋ　３００ｍｍ（３）
注入温度　１．４００〜１．４２０９Ｃ（４）熱処理 実施例　１ （１）化学成分　（重量％） （２）テストピース　φ４０　”ｌ　３００ｍｍ（３）
注入温度　１　、４００〜１．４２０　’Ｃ（４）熱処
理 （５）機械的性質 （６）組織、Ｎｏ、３は第２図に示す。・K plan example 1 (1) Chemical composition (weight%) (2) Test piece φ40'K 300mm (3)
Injection temperature 1.400-1.4209C (4) Heat treatment example 1 (1) Chemical composition (wt%) (2) Test piece φ40"l 300mm (3)
Injection temperature 1, 400-1.420'C (4) Heat treatment (5) Mechanical properties (6) Structure No. 3 is shown in FIG.

上述せる通り基地組織はベイナイト組織で、抗張力、耐
力、伸び、衝撃値などきわめて優れた機械的性質を有す
る強靭ねずみ鋳鉄である。As mentioned above, the base structure is a bainite structure, which is a strong gray cast iron having extremely excellent mechanical properties such as tensile strength, yield strength, elongation, and impact value.

以上の説明で明らかなように本発明による強靭ねずみ鋳
鉄の製造法は、鋳造品をＡ１変態域以上のある所定の温
度で鋳型から取出し、急冷する強靭ねずみ鋳鉄の製造法
であって、上記Ａ１変態域以上の温度からパーライト変
態を生ぜしぬない冷却速度で急冷し、ベイナイトとオー
ステナイトの混合組織を安定的に生ぜしぬる温度に保持
し、所定時間経過後、放冷または急冷するものである。As is clear from the above explanation, the method for manufacturing strong gray cast iron according to the present invention is a method for manufacturing strong gray cast iron in which a cast product is taken out of a mold at a predetermined temperature above the A1 transformation range and rapidly cooled. The product is rapidly cooled from a temperature above the transformation range at a cooling rate that does not cause pearlite transformation, is maintained at a lukewarm temperature that stably produces a mixed structure of bainite and austenite, and after a predetermined period of time is allowed to cool or rapidly cooled. .

従って、鋳造品の製作工程の短縮、再加熱の廃止による
製造原価の低減など経済性に優れ、しかも高強度、高靭
性など機械的性質のきわめて優れた強靭ねずみ鋳鉄を安
定して製造し得るものである。Therefore, it has excellent economic efficiency, such as shortening the manufacturing process of castings and reducing manufacturing costs by eliminating reheating, and can stably produce strong gray cast iron with extremely excellent mechanical properties such as high strength and high toughness. It is.

Claims (1)

【特許請求の範囲】[Claims] ねずみ鋳鉄組成を有する溶湯を鋳型に注湯し、凝固させ
た後動造品をＡ、変態域以上の所定の温度で鋳型から取
出し、急冷する強靭ねずみ鋳鉄の製造法において、上記
Ａ１変態域以」二の温度からパーライト変態を生せしめ
ない冷却速度で急冷し、ベイナイトとオーステナイトの
混合組織を安定的に生せしめる温度に保持し、所定時間
経過後、放冷または急冷することを特徴とする強靭ねず
み鋳鉄の製造法。A method for manufacturing strong gray cast iron, in which a molten metal having a gray cast iron composition is poured into a mold, solidified, and then the moving product is taken out of the mold at a predetermined temperature above the A transformation region and rapidly cooled. ``Toughness is characterized by rapidly cooling from the second temperature at a cooling rate that does not cause pearlite transformation, holding it at a temperature that stably forms a mixed structure of bainite and austenite, and cooling it naturally or rapidly after a predetermined period of time has elapsed. Method of manufacturing gray cast iron.
JP58160796A 1983-09-01 1983-09-01 Manufacturing method of tough gray cast iron Expired - Lifetime JP2659353B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP58160796A JP2659353B2 (en) 1983-09-01 1983-09-01 Manufacturing method of tough gray cast iron

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP58160796A JP2659353B2 (en) 1983-09-01 1983-09-01 Manufacturing method of tough gray cast iron

Publications (2)

Publication Number Publication Date
JPS6052514A true JPS6052514A (en) 1985-03-25
JP2659353B2 JP2659353B2 (en) 1997-09-30

Family

ID=15722636

Family Applications (1)

Application Number Title Priority Date Filing Date
JP58160796A Expired - Lifetime JP2659353B2 (en) 1983-09-01 1983-09-01 Manufacturing method of tough gray cast iron

Country Status (1)

Country Link
JP (1) JP2659353B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2604644A1 (en) * 1986-10-02 1988-04-08 Gisag Veb METHOD FOR ACCELERATED COOLING OF MOLDED PIECES

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54138812A (en) * 1978-03-31 1979-10-27 Standard Car Truck Co Abrasion resistant cast iron

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54138812A (en) * 1978-03-31 1979-10-27 Standard Car Truck Co Abrasion resistant cast iron

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2604644A1 (en) * 1986-10-02 1988-04-08 Gisag Veb METHOD FOR ACCELERATED COOLING OF MOLDED PIECES

Also Published As

Publication number Publication date
JP2659353B2 (en) 1997-09-30

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