JPH0445264B2 - - Google Patents
Info
- Publication number
- JPH0445264B2 JPH0445264B2 JP58052630A JP5263083A JPH0445264B2 JP H0445264 B2 JPH0445264 B2 JP H0445264B2 JP 58052630 A JP58052630 A JP 58052630A JP 5263083 A JP5263083 A JP 5263083A JP H0445264 B2 JPH0445264 B2 JP H0445264B2
- Authority
- JP
- Japan
- Prior art keywords
- casting
- cast iron
- temperature
- air
- hardening
- 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 - Lifetime
Links
- 238000005266 casting Methods 0.000 claims description 32
- 238000000034 method Methods 0.000 claims description 21
- 229910001018 Cast iron Inorganic materials 0.000 claims description 18
- 238000001816 cooling Methods 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims 1
- 239000003507 refrigerant Substances 0.000 description 10
- 239000012530 fluid Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 238000005275 alloying Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 238000001723 curing Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000003595 mist Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
- B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
Description
本発明は、鋳鉄の局部的硬化法に関し、さらに
詳しくは、鋳型内への空気または空気と水との混
合流体の流入により、鋳物の必要部分のみの冷却
速度を高めて硬化させる鋳鉄の局部的硬化法に関
する。
従来、鋳鉄を硬化させる方法としては、Mo、
Cuなどの合金元素を添加する方法、冷し金を当
てる方法、鋳物温度800〜1000℃で型ばらしを行
なう方法及び熱処理（焼ならし等）などの方法が
知られている。しかしながら、合金元素を添加す
る方法では、局部的硬化は不可能であり、またチ
ルが発生し易く、切削加工性が悪化する。また、
冷し金を当てる方法でも、切削加工性を悪化する
チルが発生し易い。一方、鋳物温度800〜1000℃
で型ばらしを行なつた場合には、硬さのバラツキ
が大きく、また鋳物の内側部分の硬化は不可能で
ある。さらに、熱処理方法では、局部的硬化は可
能であるが、再加熱を要し、経済的に不利であ
る。
本発明は、上記の事情に鑑みなされたものであ
り、その目的とするところは、チルの発生もなく
鋳鉄の局部的硬化を行なうことのできる方法を提
供することにある。
本発明者らの研究によると、鋳物の必要硬化部
分が鋳物の内側部分であつても、鋳型内部で凝
固、冷却中の鋳鉄鋳物の温度が720〜1150℃、好
ましくは780〜1000℃に到達した時点で、必要硬
化部分に応じて例えば主型あるいはさらに中子に
設けた空気孔を通じて、空気または空気と水との
混合流体を流入せしめ、鋳鉄鋳物の温度が300〜
700℃になつた時点で流入を止め、鋳物の必要部
分のみの冷却速度を高めて硬化させることによつ
て、前記したチルの発生等の問題もなく、良好に
鋳鉄の局部的硬化を行なうことができることを見
い出し、本発明を完成するに至つたものである。
すなわち、本発明に係る鋳鉄の局部的硬化法の
特徴は、鋳鉄鋳物の必要な部分のみを局部硬化で
きることにあり、この硬化を、鋳型内で、鋳物の
必要部分のみの冷却速度を高めて硬化させるもの
である。このため、冷媒として空気または空気と
水との混合流体を用い、鋳型内で冷却中の鋳物温
度が720〜1150℃、好ましくは780〜1000℃となつ
た時点で上記冷媒を鋳型内に流入せしめ、300〜
700℃となつた時点で流入を止めることを特徴と
する。
以下、添附図面を参照しながら、本発明の局部
的硬化法について詳細に説明する。
第１図は、本発明方法の一適用例を示し、ま
ず、例えばC2.8〜3.5％、Si1.5〜2.5％、残部鉄か
らなる普通鋳鉄を鋳型に鋳込み、所定形状の鋳物
１を形成する。図中、２は主型、３は中子であ
る。また、鋳物１のうちＡの部分が必要硬化部分
（被硬化処理部分）である。鋳物１は、鋳込み後、
凝固、冷却という過程を経るが、鋳物１の温度が
好ましくは780〜1000℃に到達した時点で、主型
２と中子３とを貫通して設けた空気孔４に、空気
（２〜５m3／分）と水（０〜２／分）との混合
流体を流入し、鋳物１の温度が300〜700℃になつ
た時点で流入を止める。なお、第１図に示すよう
な空気孔４を設けた場合、鋳物１の被硬化処理部
分Ａと混合流体との間に介在する中子３の薄膜部
分は、混合流体によつて徐々に吹き削られて硬化
処理終了段階では存在しなくなる。
この方法により、鋳物１の被硬化処理部分Ａ
は、ブリネル硬さ230〜270、引張強さ30〜40Kg／
mm2となり、必要な局部硬化が達成される。
前記冷媒の流入開始は、鋳物の温度が鋳鉄の凝
固温度1150℃以下となつた時点で行なえるが、共
析変態点720℃以上で開始する必要があり、好ま
しくは780〜1000℃の温度となつた時点で開始す
るようにする。
冷媒としては、空気または空気と水との混合流
体（例えばミスト状乃至霧状）が最適である。水
だけの場合（空気が混入していない水流）は鋳型
に浸透するため好ましくない。この冷媒の流量に
よつて鋳物の冷却速度は変化し、例えば、冷媒の
種類及び流量と冷却速度との関係の一例を示せ
ば、下記第１表の通りである。
The present invention relates to a method for locally hardening cast iron, and more particularly, the present invention relates to a method for locally hardening cast iron, and more particularly, the present invention relates to a method for locally hardening cast iron, which hardens cast iron by increasing the cooling rate of only necessary parts of the casting by introducing air or a mixed fluid of air and water into the mold. Concerning curing methods. Conventionally, methods for hardening cast iron include Mo,
Methods such as adding alloying elements such as Cu, applying a cold metal, breaking the mold at a casting temperature of 800 to 1000°C, and heat treatment (normalizing, etc.) are known. However, with the method of adding alloying elements, local hardening is not possible and chilling is likely to occur, resulting in poor cutting workability. Also,
Even with the method of applying a cold metal, chilling that deteriorates cutting workability is likely to occur. Meanwhile, casting temperature 800~1000℃
When demolding is carried out, there is a large variation in hardness, and it is impossible to harden the inner part of the casting. Furthermore, although local hardening is possible with the heat treatment method, reheating is required, which is economically disadvantageous. The present invention has been made in view of the above circumstances, and its purpose is to provide a method that can locally harden cast iron without generating chill. According to the research conducted by the present inventors, even if the required hardening part of the casting is the inner part of the casting, the temperature of the cast iron casting during solidification and cooling inside the mold reaches 720 to 1150°C, preferably 780 to 1000°C. At that point, air or a mixed fluid of air and water is allowed to flow in through air holes provided in the main mold or even the core depending on the required hardening part, and the temperature of the cast iron casting is brought to 300 - 300°C.
By stopping the flow when the temperature reaches 700°C and increasing the cooling rate of only the necessary parts of the casting to harden it, the cast iron can be locally hardened without the above-mentioned problems such as generation of chill. The present invention has been completed based on the discovery that this can be done. That is, the feature of the local hardening method for cast iron according to the present invention is that only the necessary parts of the cast iron casting can be locally hardened, and this hardening can be achieved by increasing the cooling rate of only the necessary parts of the casting in the mold. It is something that makes you For this reason, air or a mixed fluid of air and water is used as the refrigerant, and the refrigerant is allowed to flow into the mold when the temperature of the casting being cooled in the mold reaches 720 to 1150°C, preferably 780 to 1000°C. , 300～
It is characterized by stopping the inflow when the temperature reaches 700℃. Hereinafter, the localized curing method of the present invention will be explained in detail with reference to the accompanying drawings. FIG. 1 shows an example of application of the method of the present invention. First, ordinary cast iron consisting of, for example, 2.8 to 3.5% C, 1.5 to 2.5% Si, and the balance iron is poured into a mold to form a casting 1 of a predetermined shape. do. In the figure, 2 is the main mold, and 3 is the core. Further, the part A of the casting 1 is the required hardening part (the part to be hardened). Casting 1, after casting,
After the process of solidification and cooling, when the temperature of the casting 1 reaches preferably 780 to 1000 degrees Celsius, air (2 to 5 m A mixed fluid of 3 /min) and water (0 to 2/min) is introduced, and the inflow is stopped when the temperature of the casting 1 reaches 300 to 700°C. Note that when the air holes 4 as shown in FIG. 1 are provided, the thin film portion of the core 3 interposed between the part A to be hardened of the casting 1 and the mixed fluid is gradually blown away by the mixed fluid. It is scraped and ceases to exist at the end of the hardening process. By this method, the part to be hardened A of the casting 1
has a Brinell hardness of 230 to 270 and a tensile strength of 30 to 40 kg/
mm 2 and the necessary local hardening is achieved. The inflow of the refrigerant can be started when the temperature of the casting reaches the solidification temperature of cast iron, 1150°C or lower, but it needs to start at the eutectoid transformation point of 720°C or higher, preferably at a temperature of 780 to 1000°C. Start when you are old enough. As the refrigerant, air or a mixed fluid of air and water (for example, in the form of a mist or mist) is most suitable. It is not preferable to use only water (a water stream without air mixed in) because it will penetrate into the mold. The cooling rate of the casting varies depending on the flow rate of the refrigerant, and an example of the relationship between the type of refrigerant, the flow rate, and the cooling rate is shown in Table 1 below.
【表】
また、冷媒の流量によつて冷却速度が変わると
共に、冷却速度の相違によつて鋳物の被硬化処理
部分のブリネル硬さ、引張強さ等の機械的性質も
当然に変化する。冷却速度のブリネル硬さ及び引
張強さに及ぼす影響を第２図に示す。第２図にお
いて、鋳鉄ａ及びｂの化学成分は以下のとおりで
ある。
ａ：C3.35〜3.45％、Si2.00〜2.10％、残部鉄
ｂ：C3.35〜3.45％、Si2.00〜2.10％、Cr0.25〜
0.35％、残部鉄
第２図から、ブリネル硬さ及び引張強さ共に冷
却速度が高い程大きいことが解る。従つて、冷媒
の種類及び量は、冷却速度に応じて、すなわち被
硬化処理部分の所望の機械的性質に応じて適宜設
定すればよい。
次に、本発明の局部的硬化法により製造した鋳
物の機械的性質を下記第２表に示す。比較とし
て、合金添加法による例も併せて示す。なお、冷
媒が空気のみの場合は、鋳物温度が920〜940℃の
時点で流入を開始し、600℃となつた時点で流入
を停止した。また、冷媒として空気と水との混合
流体を用いた場合には、900〜920℃で流入を開始
し、600℃となつた時点で流入を止めた。[Table] In addition, the cooling rate changes depending on the flow rate of the refrigerant, and the mechanical properties such as Brinell hardness and tensile strength of the hardened part of the casting naturally change due to the difference in the cooling rate. The effect of cooling rate on Brinell hardness and tensile strength is shown in FIG. In FIG. 2, the chemical components of cast irons a and b are as follows. a: C3.35~3.45%, Si2.00~2.10%, balance iron b: C3.35~3.45%, Si2.00~2.10%, Cr0.25~
0.35%, balance iron From Figure 2, it can be seen that both Brinell hardness and tensile strength increase as the cooling rate increases. Therefore, the type and amount of the refrigerant may be appropriately set depending on the cooling rate, that is, the desired mechanical properties of the part to be hardened. Next, the mechanical properties of castings produced by the local hardening method of the present invention are shown in Table 2 below. For comparison, an example using the alloy addition method is also shown. In addition, when the refrigerant was only air, the inflow was started when the casting temperature was 920 to 940°C, and the inflow was stopped when the temperature reached 600°C. Further, when a mixed fluid of air and water was used as the refrigerant, the inflow was started at 900 to 920°C and stopped when the temperature reached 600°C.
【表】
本発明に係る鋳鉄の局部的硬化法は、例えばド
ライライナータイプのガソリン及びデイーゼルエ
ンジン用シリンダブロツクのライナ部等の硬化処
理に最適に応用することができる。従来、このよ
うなライナ部の硬度をブリネル硬さHB＝230程度
にするには、Cr、Mo、Cuなどの合金元素を添加
した材質で鋳造しているが、鋳造性の悪化、シリ
ンダブロツク全体の硬化、薄肉部（スカート部）
でのチル発生などの問題点がある。ところが、全
体を同一材質（普通鋳鉄：JIS G5501に規定する
FC20またはFC25相当）で鋳造し、この鋳造段階
で、前記した本発明の局部的硬化法を適用するこ
とにより、ライナー部の硬さのみがHB＝230〜
250を有し、他の部位はそれ以下の硬さを有する
ドライライナータイプのガソリン及びデイーゼル
エンジン用シリンダブロツクが得られ、鋳造性の
悪化、薄肉部でのチル発生などの不具合を生ずる
ことなく、ライナー部の耐摩耗性を向上すること
ができる。[Table] The method of locally hardening cast iron according to the present invention can be optimally applied to, for example, hardening treatment of liner portions of dry liner type gasoline and diesel engine cylinder blocks. Conventionally, in order to make the hardness of the liner part about 230 (Brinell hardness H B = 230), the liner was cast with a material containing alloying elements such as Cr, Mo, and Cu, but this resulted in deterioration of castability and damage to the cylinder block. Overall hardening, thin wall part (skirt part)
There are problems such as chill generation. However, the entire material is made of the same material (regular cast iron: specified in JIS G5501).
By casting with FC20 or FC25 (equivalent to FC20 or FC25) and applying the above-described local hardening method of the present invention at this casting stage, only the hardness of the liner part can be reduced to H B = 230 ~
250, and other parts have hardness less than that, a dry liner type cylinder block for gasoline and diesel engines can be obtained, without causing problems such as deterioration of castability or occurrence of chill in thin-walled parts. The wear resistance of the liner portion can be improved.
第１図は、本発明の局部的硬化法の適用方法例
を示す鋳造状態の概略断面図、第２図は冷却速度
とブリネル硬さ、引張強さとの関係を示すグラフ
である。
１は鋳物、２は主型、３は中子、４は空気孔、
Ａは被硬化処理部。
FIG. 1 is a schematic sectional view of a cast state showing an example of the application method of the local hardening method of the present invention, and FIG. 2 is a graph showing the relationship between cooling rate, Brinell hardness, and tensile strength. 1 is the casting, 2 is the main mold, 3 is the core, 4 is the air hole,
A is the part to be hardened.
Claims (1)
1150℃に到達した時点で、鋳物の硬化が要求され
る必要部分に相当する鋳型内に、直接的に空気ま
たは空気と水とのミスト状混合気流を流入せし
め、その後鋳鉄鋳物の温度が300〜700℃になつた
時点で流入を止め、鋳物の必要部分のみの冷却速
度を高めて硬化させることを特徴とする鋳鉄の局
部的硬化法。1 The temperature of the cast iron casting while cooling in the mold is 720~
When the temperature reaches 1150℃, air or a mist-like air mixture of air and water is directly introduced into the mold corresponding to the necessary parts that require hardening of the casting, and then the temperature of the cast iron casting is reduced to 300℃. A localized hardening method for cast iron that stops the flow when the temperature reaches 700°C and increases the cooling rate of only the necessary parts of the casting to harden it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5263083A JPS59179263A (en) | 1983-03-30 | 1983-03-30 | Local hardening method of cast iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5263083A JPS59179263A (en) | 1983-03-30 | 1983-03-30 | Local hardening method of cast iron |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59179263A JPS59179263A (en) | 1984-10-11 |
| JPH0445264B2 true JPH0445264B2 (en) | 1992-07-24 |
Family
ID=12920135
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5263083A Granted JPS59179263A (en) | 1983-03-30 | 1983-03-30 | Local hardening method of cast iron |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59179263A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0736946B2 (en) * | 1987-07-02 | 1995-04-26 | 三菱重工業株式会社 | Manufacturing method of corrosion resistant high strength marine propeller |
| JPS6415269A (en) * | 1987-07-10 | 1989-01-19 | Mitsubishi Heavy Ind Ltd | Production of marine propeller having high corrosion fatigue strength |
| JP5399180B2 (en) * | 2009-09-11 | 2014-01-29 | ヤンマー株式会社 | Casting method using a core |
| JP5416515B2 (en) * | 2009-09-11 | 2014-02-12 | ヤンマー株式会社 | Casting method using a core |
| DE102012103884A1 (en) * | 2012-05-03 | 2013-11-07 | Fritz Winter Eisengiesserei Gmbh & Co. Kg | Method for casting a casting provided with at least one passage opening |
| CN104289699A (en) * | 2014-08-18 | 2015-01-21 | 安徽惠明机械制造有限公司 | Rapid water-cooling method for pig iron casting |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5391018A (en) * | 1977-01-19 | 1978-08-10 | Svenska Flaektfabriken Ab | Method and apparatus for cooling heated body |
| JPS54141335A (en) * | 1978-04-26 | 1979-11-02 | Kubota Ltd | Making roll by casting |
| JPS57103775A (en) * | 1980-12-19 | 1982-06-28 | Nippon Cement Co Ltd | Production of casting made of high chromium cast iron |
-
1983
- 1983-03-30 JP JP5263083A patent/JPS59179263A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5391018A (en) * | 1977-01-19 | 1978-08-10 | Svenska Flaektfabriken Ab | Method and apparatus for cooling heated body |
| JPS54141335A (en) * | 1978-04-26 | 1979-11-02 | Kubota Ltd | Making roll by casting |
| JPS57103775A (en) * | 1980-12-19 | 1982-06-28 | Nippon Cement Co Ltd | Production of casting made of high chromium cast iron |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59179263A (en) | 1984-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5921312A (en) | Soluble core for casting | |
| CN101928872A (en) | Production method of low-magnetic iron castings | |
| EP1131175B1 (en) | Method and device for chill moulding | |
| JP5085839B2 (en) | Gray cast iron for cylinder head | |
| US3965962A (en) | Process for producing ductile iron casting | |
| JPH0445264B2 (en) | ||
| JP2002309935A (en) | Exhaust system parts of heat-resisting steel | |
| JP2879005B2 (en) | Cooling method of casting | |
| AU633154B2 (en) | Method of controlling the rate of heat extraction in mould casting | |
| WO2004101197A3 (en) | Method for centrifugal casting | |
| JPH06142869A (en) | Method and device for producing cast iron made cylinder liner | |
| JPH0399767A (en) | Method for manufacturing internal chilling piping in casting metallic mold | |
| JP2002192328A (en) | Method for manufacturing spheroidal graphite cast iron member | |
| JPH0128667B2 (en) | ||
| US3438424A (en) | Method of direct casting of steel slabs and billets | |
| JPS643594B2 (en) | ||
| JP2004114159A (en) | Pressure-resistant high-strength cast aluminum cylinder head | |
| SU791447A1 (en) | Ingot centrifugal casting method | |
| JPS6349582B2 (en) | ||
| JPS59189033A (en) | Production of aluminum alloy casting | |
| JPS6199539A (en) | Nonferrous clad ingot and its production | |
| SU453238A1 (en) | METHOD OF CASTING OF IRON ROLLS | |
| JP2002018566A (en) | Injection sleeve for die casting machine | |
| JPS62212008A (en) | Sleeve roll with caliber for rolling | |
| JPH11236641A (en) | Composite material of cast iron and production of composite material |