JP2597032B2 - Local softening method of casting - Google Patents
Local softening method of castingInfo
- Publication number
- JP2597032B2 JP2597032B2 JP2101015A JP10101590A JP2597032B2 JP 2597032 B2 JP2597032 B2 JP 2597032B2 JP 2101015 A JP2101015 A JP 2101015A JP 10101590 A JP10101590 A JP 10101590A JP 2597032 B2 JP2597032 B2 JP 2597032B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- camshaft
- heating
- casting
- mold
- 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.)
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Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
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- Heat Treatment Of Articles (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は金型等を用いて鋳造した鋳造品の一部を鋳造
後に焼鈍して軟化せしめる方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for annealing and softening a part of a cast product cast using a mold or the like after casting.
（従来の技術） 金型を用いて鋳鉄部材を鋳造する方法として特開昭63
−174775号が知られている。(Prior Art) As a method of casting a cast iron member using a mold, Japanese Patent Application Laid-Open
No. 174775 is known.
この方法はカムシャフト等の鋳物を鋳造するにあた
り、金型のキャビティ内に溶湯を充填した後、溶湯の表
層を急冷して殻状の凝固層とし、この時点で離型するよ
うにしたものである。このようにすることで、金型に変
形や摩耗を生じることなく、表層が高硬度のチル組織と
なったカムシャフトが得られる。In this method, when casting a casting such as a camshaft, after filling the molten metal in the cavity of the mold, the surface layer of the molten metal is rapidly cooled to a shell-like solidified layer, and the mold is released at this time. is there. By doing so, a camshaft having a surface layer having a high hardness chill structure can be obtained without causing deformation or wear in the mold.
上述したように金型を用いてカムシャフト等を鋳造す
れば、砂型を用いた場合に比べ、効率良く且つコスト的
にも有利に鋳物が得られる。As described above, when a camshaft or the like is cast using a mold, a casting can be obtained more efficiently and more cost-effectively than when a sand mold is used.
しかしながら金型を使用する場合には、砂型に冷し金
をセットする場合と異なり、鋳物の表層全体がチル化
し、鋳造後にセンター穴やスプライン溝を加工すべき部
分の硬度が硬くなり過ぎ、刃具の寿命等の点で不利が生
じる。However, when using a mold, unlike the case where a cooling die is set in a sand mold, the entire surface layer of the casting is chilled, and the hardness of the part where the center hole and spline grooves are to be machined after casting becomes too hard, and the cutting tool Disadvantageous in terms of the life of the device.
そこで第５図に示すように一旦鋳造した鋳物の一部を
高周波等を利用して再加熱し、次いで一定時間高温状態
で保持した後に放冷することで当該一部を焼鈍軟化する
方法が考えられるが、この方法のように一定速度でチル
組織となっている鋳物を加熱すると以下の問題がある。Therefore, as shown in FIG. 5, a method of reheating a part of the casting once cast by using high frequency or the like, and then keeping it in a high temperature state for a certain period of time and then allowing it to cool by annealing is considered. However, when a casting having a chill structure is heated at a constant speed as in this method, there are the following problems.
（発明が解決しようとする課題） 即ち、鋳鉄は鋳込んでから常温まで冷却せしめる間に
以下の３つの容積変化を行う。(Problems to be Solved by the Invention) That is, the following three volume changes occur during the casting of the cast iron and the cooling of the cast iron to room temperature.
鋳込み温度から凝固点までの液体としての収縮。 Shrinkage as liquid from casting temperature to freezing point.
凝固による容積変化。（白銑鉄は収縮、灰銑銑は膨
張） 固体の冷却（変態）による膨張又は収縮。Volume change due to coagulation. (White pig iron contracts, gray pig iron expands) Expansion or contraction due to cooling (transformation) of solids.
そして、上記，が鋳造後の残留応力の原因とな
り、この残留応力は構造応力と組織応力に分けられる。
構造応力とは鋳造品の各部の冷却速度が異なることに起
因して発生する応力で、組織応力は組織や組成の分布及
び大きさなどの材質の差に起因して発生する応力があ
る。The above causes the residual stress after casting, and the residual stress is divided into structural stress and structural stress.
Structural stress is a stress generated due to a difference in the cooling rate of each part of a casting, and structural stress is a stress generated due to a difference in material such as a structure and a distribution and a size of a composition.
先ず、構造応力の面から述べると、残留応力の発生過
程は凝固、冷却時の始めは、表層は速く冷却するため収
縮して引張応力状態となり内部は圧縮応力状態となる。
ここで表層より温度の高い可塑的な内部がこの圧縮応力
によって塑性変形を行なうと、その部分の実質寸法は縮
小する。するとこれによりさらに冷却の進んだ段階では
その応力状態は逆転し、表層に圧縮、内部に引張りの残
留応力が発生し、その境界近くに引張りの極大が現われ
る。First, in terms of structural stress, the process of generation of residual stress is solidification, and at the beginning of cooling, the surface layer is rapidly cooled and contracts to become a tensile stress state, and the inside becomes a compressive stress state.
Here, when the plastic inside having a higher temperature than the surface layer undergoes plastic deformation due to the compressive stress, the substantial size of the portion is reduced. As a result, at the stage of further cooling, the stress state is reversed, a compressive stress is generated in the surface layer and a tensile residual stress is generated inside, and a maximum tensile strength appears near the boundary.
一方、組織応力の面から述べると、金型鋳造に於て
は、その金型に接する面は冷却速度が極めて早いため表
層は白銑組織（パーライト及びレーデブライト）とな
り、冷却速度の遅い内部は灰銑組織（黒鉛及びパーライ
ト）となり、そしてその境界部は斑銑（パーライト、黒
鉛及びレーデブライト）となる。この葉に表層と内部と
が組織を異にし従がって比容積を異にする。この比容積
の差によって表層に圧縮、内部に引張りの応力を生じ、
この影響が集中的に現われる境界部では圧縮、引張りと
も大きくなる傾向にある。On the other hand, in terms of microstructural stress, in die casting, the surface in contact with the die has a very high cooling rate, so the surface layer has a white iron structure (pearlite and redebrite), and the inside with a low cooling rate has ash. It becomes a pig structure (graphite and pearlite) and its border is spotted iron (pearlite, graphite and leedrite). The surface layer and the inside of this leaf have different tissues and accordingly have different specific volumes. Due to this difference in specific volume, compression occurs on the surface layer and tensile stress occurs inside,
At the boundary where this effect appears intensively, both compression and tension tend to increase.
以上述べた様に金型鋳造に於ては熱応力による残留応
力と表層の内部の組織の相違による残留応力が重畳す
る。このような鋳造応力は加熱により除去でき鋳物を加
熱してゆくと300〜500℃の間で応力は急激に減少し、60
0℃ではほとんど消失する。As described above, in die casting, the residual stress due to thermal stress and the residual stress due to the difference in the structure inside the surface layer are superimposed. Such a casting stress can be removed by heating, and as the casting is heated, the stress rapidly decreases between 300 and 500 ° C.
Almost disappears at 0 ° C.
そこで、上述の残留応力分布状態、即ち表層が圧縮、
内部が引張り、境界部付近が引張り極大にある金型鋳造
品を高周波加熱により、急速加熱すると、表層のみが加
熱され表層部の体積膨張により熱応力が発生する。この
熱応力は加熱の初期に発生し、表層は圧縮、内部は引張
りとなる。この高周波による急速加熱により金型鋳造部
材の表層と内部の境界に存在する引張りの極大が急速加
熱による熱応力の引張りを助長し、チル層直下を起点と
するクラックを発生させる。Therefore, the above-mentioned residual stress distribution state, that is, the surface layer is compressed,
When a mold casting having an internal tension and a tensile maximum near the boundary is rapidly heated by high-frequency heating, only the surface layer is heated and thermal stress is generated due to volume expansion of the surface layer portion. This thermal stress occurs in the early stage of heating, and the surface layer is compressed and the inside is tensile. Due to the rapid heating by the high frequency, the maximum of the tension existing on the boundary between the surface layer and the inside of the mold casting member promotes the thermal stress due to the rapid heating, and a crack starting from immediately below the chill layer is generated.
また、局部急速加熱により軸方向に於て、加熱部と非
加熱部との間において、苛酷な応力が発生する。即ち急
速加熱部が近傍の低温部に拘束されて生ずる熱応力によ
り加熱部に塑性変形が起こり、このため加熱部と非加熱
部との境界部付近に引張りの極大が生じ、境界部付近を
起点とするクラックを発生するか或いは境界部付近から
変形する。In addition, severe stress is generated between the heated portion and the non-heated portion in the axial direction due to the local rapid heating. That is, plastic deformation occurs in the heated part due to the thermal stress generated by the rapid heating part being restrained by the nearby low-temperature part, and therefore, the maximum of tension occurs near the boundary between the heated part and the non-heated part, and the starting point near the boundary part Or a deformation near the boundary.
（課題を解決するための手段） 上記課題を解決するために本発明は、Ｃを3.2〜3.6wt
％、Siを1.7〜1.8wt％、Mnを0.5〜0.7wt％、Ｐを0.1wt
％以下、Ｓを0.1wt％以下含むFC20〜FC30相当の鋳鉄、
又はNiを0.4〜0.6wt％、Crを0.5〜1.0wt％、Moを0.5〜
1.0wt％含む鋳鉄の溶湯を金型内に注湯した後、金型と
接触する溶湯表層部が高硬度チル組織の殻状の凝固層と
なった時点で離型してカムシャフトを得る鋳造工程と、 離型したカムシャフトのジャーナル部に誘導コイルを
臨ませ、ジャーナル部がA1変態点以下で600℃以上の温
度範囲にあるときに、高周波誘導加熱を開始し、1000〜
1100℃に達したらその温度に保持する昇温・保持工程
と、 次に高周波誘導加熱を停止してカムシャフトを常温ま
で冷却する冷却工程と、 常温のカムシャフト全体を炉内にて550〜600℃まで加
熱・保持して応力を除去する焼鈍工程とを実施すること
で、ジャーナル部をソルバイト組織にすることを特徴と
した鋳造品の局部軟化方法である。(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides C of 3.2 to 3.6 wt.
%, Si 1.7-1.8wt%, Mn 0.5-0.7wt%, P 0.1wt
% Or less, cast iron equivalent to FC20-FC30 containing S below 0.1 wt%
Or, Ni 0.4-0.6wt%, Cr 0.5-1.0wt%, Mo 0.5-
After pouring a cast iron melt containing 1.0 wt% into the mold, when the surface layer of the melt that comes into contact with the mold becomes a shell-like solidified layer with a high hardness chill structure, it is cast to obtain a camshaft. a step, to face the induction coil to the journal portion of the demolded camshaft journal portion when in the temperature range above 600 ° C. or less a 1 transformation point, to start the high-frequency induction heating, 1000
When the temperature reaches 1100 ° C, a temperature-raising / holding step of maintaining the temperature, a cooling step of stopping high-frequency induction heating and cooling the camshaft to room temperature, and a whole camshaft at room temperature in a furnace at 550 to 600 A method for locally softening a cast product, characterized by performing an annealing step of removing stress by heating and holding to a temperature of ° C., so that the journal part has a sorbite structure.
（作用） 離型後の昇温開始温度がA1変態点を超えると高周波誘
導加熱における加熱効率が極端に低下して消費電力が嵩
む。また、昇温開始温度が600℃未満になると、昇温時
に大きな熱応力が発生して割れる虞れがある。エネルギ
ー効率と品質維持の観点から、昇温開始温度をA1変態点
以下で600℃以上とした。(Action) temperature increase start temperature after the release of more than A 1 transformation point when the heating efficiency in the high-frequency induction heating increase is extremely reduced by the power consumption. If the temperature rise start temperature is lower than 600 ° C., a large thermal stress may be generated at the time of temperature rise and cracking may occur. From the viewpoint of energy efficiency and quality maintenance, the temperature rise start temperature was set to 600 ° C. or higher at the A 1 transformation point or lower.
そして、1000〜1100℃の昇温・保持により、チル層に
存在するパーライト部分が短時間でオーステナイト化す
る。Then, the pearlite portion existing in the chill layer is austenitized in a short time by raising and holding the temperature at 1000 to 1100 ° C.
次の冷却でジャーナル部にマルテンサイトが析出す
る。By the next cooling, martensite precipitates in the journal.
そこで、550〜600℃の焼鈍工程を実施することで、ジ
ャーナル部をHRC35以下のソルバイト組織にする。な
お、HRCはロックウエルＣ硬さを意味する。Therefore, by performing an annealing process at 550 to 600 ° C., the journal portion has a sorbite structure of HRC35 or less. HRC means Rockwell C hardness.
ソルバイト組織は耐摩耗性に富み、ジャーナル部の摩
耗を抑えることができる。The sorbite structure is rich in wear resistance and can suppress the wear of the journal.
（実施例） 以下に本発明の実施例を添付図面に基いて説明する。(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.
第１図は本発明方法に係る局部軟化方法を実施する前
のカムシャフトの断面図、第２図は局部軟化方法を実施
した後のカムシャフトの断面図であり、カムシャフト１
は複数のカム部２…を対をなすように軸方向に離間して
一体的に形成し、これら対をなすカム2,2の間及びカム
シャフト１両端にジャーナル部３を設けている。FIG. 1 is a cross-sectional view of a camshaft before the local softening method according to the present invention is performed, and FIG. 2 is a cross-sectional view of the camshaft after the local softening method is performed.
Are formed integrally with each other in the axial direction so as to form a pair, and journal portions 3 are provided between the pair of cams 2, 2 and at both ends of the camshaft 1.
また、カムシャフト１は［表］に示すJISFC20〜FC30
相当の鋳鉄成分からなる。The camshaft 1 is JISFC20-FC30 shown in [Table].
Consists of considerable cast iron components.
そして上記の成分からなる溶湯を金型に注入してカム
シャフト１を鋳造する。ここで鋳造に用いる金型は例え
ば0.8〜4.0wt％のCrを含有するCu−Cr合金から構成され
る熱伝導率の高いものとし、好ましくはカムシャフト１
の表面部を急冷するための冷却路を内部に形成したもの
とする。 Then, the molten metal composed of the above components is injected into a mold to cast the camshaft 1. Here, the mold used for casting has a high thermal conductivity composed of, for example, a Cu-Cr alloy containing 0.8 to 4.0 wt% of Cr.
It is assumed that a cooling passage for quenching the surface portion is formed inside.
而して斯る構造の金型のキャビティ内に溶湯を注入す
ることで、表層部1aがHRC40〜50（特にカム部はHRC45以
上）のチル組織となり、芯部1bがHRC40以下の組織とな
る。Thus, by injecting the molten metal into the cavity of the mold having such a structure, the surface layer portion 1a has a chill structure of HRC40 to 50 (especially the cam portion is HRC45 or more), and the core portion 1b has a structure of HRC40 or less. .
以上のカムシャフトの一部、例えば両端のジャーナル
部３を軟化せしめるには第３図に示すように、まず金型
鋳造における離型後の赤熱状態（600〜900℃）にある、
カムシャフトの所要軟化部分であるジャーナル部を誘導
コイルなどの高周波加熱部材４により1000〜1100℃まで
急速加熱する。このように赤熱状態からの加熱により、
表層部と内部との温度差及びジャーナル部と他の部分
（カム部）との温度差を小さくできるので、加熱による
クラック及び変形の発生を防止できる。またジャーナル
部以外への伝熱を抑制できる。In order to soften a part of the camshaft, for example, the journal portions 3 at both ends, as shown in FIG. 3, first, the mold is in a red-hot state (600 to 900 ° C.) after mold release in mold casting.
The journal, which is the required softened portion of the camshaft, is rapidly heated to 1000 to 1100 ° C. by the high-frequency heating member 4 such as an induction coil. Thus, by heating from the red heat state,
Since the temperature difference between the surface layer portion and the inside and the temperature difference between the journal portion and another portion (cam portion) can be reduced, cracks and deformation due to heating can be prevented. Further, heat transfer to portions other than the journal portion can be suppressed.
引き続いて行なう保持加熱にあってはジャーナル部３
の温度を1000〜1100℃に20〜30秒維持する。この保持加
熱により、チル層を構成するレーデブライト共晶中のセ
メンタイトの一部は、分解し、黒鉛化される。For the subsequent holding and heating, the journal part 3
Maintain the temperature at 1000-1100 ° C for 20-30 seconds. By this holding and heating, part of the cementite in the redebrite eutectic constituting the chill layer is decomposed and graphitized.
ここで、第３図に示す実施例にあっては高周波加熱を
スタートする温度を600℃以上でA1変態点（738℃）以下
としている。この場合にはチル層に存在するパーライト
組織がオーステナイト組織に変化する。Here, in the embodiment shown in Figure 3 is less A 1 transformation point temperature to start the high-frequency heating at 600 ° C. or higher (738 ° C.). In this case, the pearlite structure existing in the chill layer changes to an austenite structure.
次に上記状態にあるカムシャフトを放冷する。この放
冷により、上記オーステナイト部分はマルテン化し、硬
化する。Next, the camshaft in the above state is allowed to cool. By this cooling, the austenite portion is martensized and hardened.
次に再加熱により550〜600℃で２時間の条件により電
気炉を用いて鋳造応力除去のための焼鈍を行う。焼鈍に
より、鋳造時に発生した鋳造応力が除去されると共にジ
ャーナル部表層のマルテンサイト化部分はHRC35以下の
ソルバイト組織となる。Next, annealing for removing casting stress is performed by using an electric furnace at 550 to 600 ° C. for 2 hours by reheating. By annealing, the casting stress generated at the time of casting is removed, and the martensitized portion of the surface layer of the journal has a sorbite structure of HRC 35 or less.
また上記焼鈍条件により、ジャーナル部以外のセメン
タイトの黒鉛化は生じない。Under the above annealing conditions, graphitization of cementite other than the journal portion does not occur.
（発明の効果） 第４図は以下の条件によって軟化処理した後のカムシ
ャフトの各部の残留応力を示すものである。(Effect of the Invention) FIG. 4 shows the residual stress of each part of the camshaft after softening under the following conditions.
条件： 高周波加熱前ワーク温度 650℃及び780℃ 高周波昇温加熱条件 （ａ）周波数……5KHz/sec （ｂ）出力……26Kw （ｃ）加熱時間……15秒 （ｄ）加熱温度……1.050℃ 高周波保持加熱条件 （ａ）周波数……3KHz/sec （ｂ）出力……18Kw （ｃ）保持時間……30秒 （ｄ）加熱温度……1.050℃ 電気炉焼鈍条件 （ａ）加熱温度……600℃ （ｂ）保持時間……2H 第４図および以上の説明から明らかなように本発明に
よれば、離型直後の赤熱状態（600〜900℃）にある鋳造
品の一部を高周波加熱することで表層部と内部との温度
差を小さくしたので、加熱により発生する熱応力も非常
に小さく、所要加熱温度まで急速加熱をしてもクラック
の発生を防止できる。また、加熱部分とその他の部分と
の温度差が少ないため、高周波加熱による変形が少な
い。更に急速加熱の為、不必要部分まで熱が伝わること
を抑制できるので不必要部分の軟化を防止できる。Conditions: Work temperature before high-frequency heating 650 ° C and 780 ° C High-frequency heating and heating conditions (a) Frequency: 5KHz / sec (b) Output: 26Kw (c) Heating time: 15 seconds (d) Heating temperature: 1.050 ℃ High-frequency holding and heating conditions (a) Frequency 3 KHz / sec (b) Output 18 Kw (c) Holding time 30 seconds (d) Heating temperature 1.050 ° C Electric furnace annealing conditions (a) Heating temperature 600 ° C. (b) Holding time 2H According to the present invention, as is apparent from FIG. 4 and the above description, a part of the casting in the red-hot state (600 to 900 ° C.) immediately after the release is heated by high frequency. By doing so, the temperature difference between the surface layer portion and the inside is reduced, so that the thermal stress generated by heating is very small, and the generation of cracks can be prevented even if rapid heating to the required heating temperature is performed. Further, since the temperature difference between the heated portion and the other portions is small, deformation due to high-frequency heating is small. Further, since rapid heating can prevent heat from being transmitted to unnecessary portions, softening of unnecessary portions can be prevented.
第１図は本発明方法に係る局部軟化方法を実施する前の
カムシャフトの断面図、第２図は局部軟化方法を実施し
た後のカムシャフトの断面図、第３図は本発明方法の加
熱パターンを示すグラフ、第４図は焼鈍後のカムシャフ
トの各部の残留応力を示す図、第５図は従来方法を示す
グラフである。 尚、図面中１はカムシャフト、1aは表層部、1bは芯部、
２はカム部、３はジャーナル部、４は加熱部材（誘導コ
イル）である。FIG. 1 is a cross-sectional view of a camshaft before a local softening method according to the present invention is performed, FIG. 2 is a cross-sectional view of a camshaft after a local softening method is performed, and FIG. FIG. 4 is a graph showing the pattern, FIG. 4 is a graph showing the residual stress of each part of the camshaft after annealing, and FIG. 5 is a graph showing the conventional method. In the drawings, 1 is a camshaft, 1a is a surface layer, 1b is a core,
Reference numeral 2 denotes a cam portion, 3 denotes a journal portion, and 4 denotes a heating member (induction coil).
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ２２Ｃ 37/08 Ｃ２２Ｃ 37/08 Ｚ (72)発明者 原田 浩久 三重県鈴鹿市竹野２―５―７ (72)発明者 松本 勲 神奈川県秦野市南矢名小南前2044 秦野 マンションＡ312 (72)発明者 江原 誠二 三重県鈴鹿市南玉垣町字玉垣5532 サテ ライト玉垣201 (56)参考文献 特開 平２−149640（ＪＰ，Ａ)──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code Agency reference number FI Technical indication C22C 37/08 C22C 37/08 Z (72) Inventor Hirohisa Harada 2-5- Takeno, Suzuka-shi, Mie Prefecture 7. 149640 (JP, A)
Claims (1)
を0.5〜0.7wt％、Ｐを0.1wt％以下、Ｓを0.1wt％以下含
むFC20〜FC30相当の鋳鉄、又はNiを0.4〜0.6wt％、Crを
0.5〜1.0wt％、Moを0.5〜1.0wt％含む鋳鉄の溶湯を金型
内に注湯した後、金型と接触する溶湯表層部が高硬度チ
ル組織の殻状の凝固層となった時点で離型してカムシャ
フトを得る鋳造工程と、 離型したカムシャフトのジャーナル部に誘導コイルを臨
ませ、ジャーナル部がA1変態点以下で600℃以上の温度
範囲にあるときに、高周波誘導加熱を開始し、1000〜11
00℃に達したらその温度に保持する昇温・保持工程と、 次に高周波誘導加熱を停止してカムシャフトを常温まで
冷却する冷却工程と、 常温のカムシャフト全体を炉内にて550〜600℃まで加熱
・保持して応力を除去する焼鈍工程とを実施すること
で、ジャーナル部をソルバイト組織にすることを特徴と
した鋳造品の局部軟化方法。C. 3.2 to 3.6 wt% of C, 1.7 to 1.8 wt% of Si, Mn
0.5 to 0.7 wt%, P is 0.1 wt% or less, S is 0.1 wt% or less Cast iron equivalent to FC20 to FC30, or Ni is 0.4 to 0.6 wt%, Cr is
After pouring a molten cast iron containing 0.5 to 1.0 wt% and 0.5 to 1.0 wt% Mo into the mold, the surface of the molten metal that comes into contact with the mold becomes a shell-like solidified layer with a high hardness chill structure. in releasing and a casting step of obtaining a camshaft, to face the induction coil to the journal portion of the demolded camshaft, when the journal portion is in a temperature range above 600 ° C. or less a 1 transformation point, high frequency induction Start heating, 1000-11
When the temperature reaches 00 ° C., a temperature raising / holding step of maintaining the temperature, a cooling step of stopping high-frequency induction heating and cooling the camshaft to room temperature, and a whole room temperature camshaft in a furnace at 550 to 600 ° C. A local softening method for a cast product, characterized by performing an annealing step of removing stress by heating and holding to a temperature of ° C., so that a journal portion has a sorbite structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2101015A JP2597032B2 (en) | 1990-04-17 | 1990-04-17 | Local softening method of casting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2101015A JP2597032B2 (en) | 1990-04-17 | 1990-04-17 | Local softening method of casting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04316A JPH04316A (en) | 1992-01-06 |
| JP2597032B2 true JP2597032B2 (en) | 1997-04-02 |
Family
ID=14289390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2101015A Expired - Fee Related JP2597032B2 (en) | 1990-04-17 | 1990-04-17 | Local softening method of casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2597032B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020054533A (en) * | 2000-12-28 | 2002-07-08 | 이계안 | Heat treatment for removing residual stress of cast iron |
| JP4165857B2 (en) * | 2001-09-27 | 2008-10-15 | 本田技研工業株式会社 | Method for producing cast iron member |
| KR20040013801A (en) * | 2002-08-08 | 2004-02-14 | 현대자동차주식회사 | Heat treatment method for removing residual stress of cylinder head |
| JP5552884B2 (en) * | 2010-04-27 | 2014-07-16 | 日本精工株式会社 | Manufacturing method of wheel bearing rolling bearing unit |
| CN112553418A (en) * | 2021-01-26 | 2021-03-26 | 东风汽车紧固件有限公司 | Local high-frequency annealing device for sleeve part and processing method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06104877B2 (en) * | 1988-11-30 | 1994-12-21 | 本田技研工業株式会社 | Method for manufacturing wear resistant member |
-
1990
- 1990-04-17 JP JP2101015A patent/JP2597032B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04316A (en) | 1992-01-06 |
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