JPH0210223B2 - - Google Patents
Info
- Publication number
- JPH0210223B2 JPH0210223B2 JP18568982A JP18568982A JPH0210223B2 JP H0210223 B2 JPH0210223 B2 JP H0210223B2 JP 18568982 A JP18568982 A JP 18568982A JP 18568982 A JP18568982 A JP 18568982A JP H0210223 B2 JPH0210223 B2 JP H0210223B2
- Authority
- JP
- Japan
- Prior art keywords
- gear
- clutch cone
- heat treatment
- welding
- cast iron
- 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
- 238000003466 welding Methods 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 24
- 238000004519 manufacturing process Methods 0.000 claims description 20
- 229910001018 Cast iron Inorganic materials 0.000 claims description 16
- 239000010959 steel Substances 0.000 claims description 15
- 238000011282 treatment Methods 0.000 claims description 15
- 239000002131 composite material Substances 0.000 claims description 14
- 238000005255 carburizing Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 229910001208 Crucible steel Inorganic materials 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 description 41
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 18
- 230000005540 biological transmission Effects 0.000 description 17
- 239000011324 bead Substances 0.000 description 16
- 229910052799 carbon Inorganic materials 0.000 description 16
- 229910001563 bainite Inorganic materials 0.000 description 12
- 238000010791 quenching Methods 0.000 description 11
- 230000000171 quenching effect Effects 0.000 description 11
- 229910001567 cementite Inorganic materials 0.000 description 10
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 10
- 229910001566 austenite Inorganic materials 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 229910001141 Ductile iron Inorganic materials 0.000 description 5
- 238000010894 electron beam technology Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 238000005279 austempering Methods 0.000 description 3
- 238000005256 carbonitriding Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000005304 joining Methods 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 3
- 229910001562 pearlite Inorganic materials 0.000 description 3
- 230000000717 retained effect Effects 0.000 description 3
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000010273 cold forging Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000005259 measurement 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
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 239000013585 weight reducing agent Substances 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Arc Welding In General (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Description
【発明の詳細な説明】
この発明は、鋳鉄と鋼とを溶接してなる複合部
品の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite part made by welding cast iron and steel.
従来、第１図に示すような自動車用ミツシヨン
ギヤ１を製造する場合、該ミツシヨンギヤ１を一
体的に加工しようとすると加工工具が干渉し、長
尺のミツシヨンギヤ１しか加工できないことか
ら、ミツシヨンギヤ１のギヤ部２及びクラツチコ
ーン部３をそれぞれ別個に形成し、それらを結合
させるようにしていた（例えば実開昭55−151928
号参照）。そしてこのギヤ２とクラツチコーン３
との結合方法としては、次のような(i)〜(iii)の方法
が採用されていた。即ち、
(i) ギヤ２の筒状の突出部２ａ外面及びクラツチ
コーン３の内面３ａにそれぞれセレーシヨン加
工を施こし、両者を圧入によつて結合させる。 Conventionally, when manufacturing an automobile transmission gear 1 as shown in FIG. The part 2 and the clutch cone part 3 were formed separately, and they were combined (for example, in Japanese Utility Model Application No. 55-151928)
(see issue). And this gear 2 and clutch cone 3
The following methods (i) to (iii) have been adopted as the method of coupling with. That is, (i) the outer surface of the cylindrical protrusion 2a of the gear 2 and the inner surface 3a of the clutch cone 3 are respectively subjected to serration processing, and the two are coupled by press-fitting.
(ii) ギヤ２の突出部２ａにセレーシヨン加工を施
こし、クラツチコーン３の内面３ａに浸炭焼入
れ後高周波焼なましを行ない、両者を圧入によ
つて結合させる。(ii) The protruding portion 2a of the gear 2 is subjected to serration processing, the inner surface 3a of the clutch cone 3 is carburized and quenched, and then induction annealed, and the two are joined by press fitting.
(iii) ギヤ２とクラツチコーン３とを嵌合させた
後、両者の当接部４を電子ビーム溶接やレーザ
ビーム溶接によつて結合させる。(iii) After the gear 2 and the clutch cone 3 are fitted, the abutting portions 4 of the two are joined together by electron beam welding or laser beam welding.
しかるにこのような従来の製造方法では、いず
れも鋼を用いており、しかもそれらを浸炭焼入・
焼戻しするようにしていたので、製造コストが高
く、しかも鋼を用いていることから、ギヤの熱処
理変形が大きく、又ギヤノイズが大きい等の欠点
があつた。このような欠点を解消するためには、
クラツチコーン３は強靭性が必要なことから鋼を
用い、またギヤ２は振動吸収性能及びコスト等を
考慮して鋳鉄を用い、両者をそれぞれ熱処理した
後、嵌合して溶接によつて結合する方法が考えら
れるが、この方法では溶接部にチル（遊離セメン
タイト）が生成し、溶接割れを生じたり、溶接部
の衝撃強さ等が低い等の欠点があつた。 However, these conventional manufacturing methods all use steel, which is carburized and quenched.
Since the gear was tempered, the manufacturing cost was high, and since steel was used, there were drawbacks such as large heat treatment deformation of the gear and large gear noise. In order to eliminate such shortcomings,
Clutch cone 3 is made of steel because of its strong toughness, and gear 2 is made of cast iron in consideration of vibration absorption performance and cost. After heat treating both parts, they are fitted and connected by welding. A method has been considered, but this method has drawbacks such as the formation of chill (free cementite) in the weld, resulting in weld cracking, and low impact strength of the weld.
本件発明者は、かかる問題点に鑑み、鋭意研究
の結果、鋳鉄と鋼の複合部品を製造する場合、溶
接後に熱処理を行なうようにすれば、溶接部の遊
離セメンタイトが分解することを知見し、これに
より大きな接合強度を得ることができるとともに
母材の強靭化を達成でき、しかもそれを１回の熱
処理によつて行なえるようにした、鋳鉄と鋼とを
溶接してなる複合部品の製造方法を発明するに到
つたものである。 In view of such problems, the inventor of the present invention has conducted intensive research and found that when manufacturing composite parts of cast iron and steel, if heat treatment is performed after welding, free cementite in the welded part will decompose. This method provides a method for manufacturing composite parts made by welding cast iron and steel, in which a large joint strength can be obtained and the base metal can be made tougher, and this can be done with a single heat treatment. This is what led us to invent this.
即ち本発明は、鋳鉄製の第１部品と浸炭鋼製の
第２部品とを電子ビーム溶接等によつて接合して
複合部品を製作した後、それを浸炭雰囲気中で
850〜950℃にて0.5〜10時間加熱した後220〜300
℃にて0.1〜３時間保持することによつて第１部
品を恒温処理にてベイナイト組織にするオーステ
ンパ処理と第２部品を浸炭焼入する処理とを同時
にできるようにしたことを特徴としている。 That is, the present invention manufactures a composite part by joining a first part made of cast iron and a second part made of carburized steel by electron beam welding or the like, and then manufactures the composite part in a carburizing atmosphere.
220-300 after heating at 850-950℃ for 0.5-10 hours
The present invention is characterized in that by holding the first part at 0.1 to 3 hours at a temperature of 0.1 to 3 hours, the first part can be subjected to an austempering process at a constant temperature to form a bainite structure, and the second part can be carburized and quenched at the same time.
以下本発明の一実施例を図について詳細に説明
する。 An embodiment of the present invention will be described in detail below with reference to the drawings.
第２図ないし第４図は本発明の一実施例方法に
よる鋳鉄と鋼とを溶接してなる複合部品の製造工
程を示し、これは自動車用ミツシヨンギヤの製造
に適用した例である。本方法によつて複合部品で
あるミツシヨンギヤ１を製造する場合、まず第１
部品であるギヤ２及び第２部品であるクラツチコ
ーン３を製造する。即ちギヤ２については、鋳鉄
材料FCD45（Ｃ：3.60％、Si：2.55％、Mn、0.24
％、Ｓ：0.01％、Mg：0.041％）を用いてギヤ２
の素材を鋳造し（鋳造工程５）、続いてこの素材
のギヤ部２ｂ及び溶接接合すべき部分である筒状
の突出部２ａを機械加工する（加工工程６）。ま
たクラツチコーン３については、浸炭鋼SCr420
（Ｃ：0.20％、Si：0.25％、Mn：0.72％、Cr：
1.13％）を用いて冷間鍛造によりクラツチコーン
３の素材を形成し（鍛造工程８）、この素材３の
溶接接合すべき部分である内面３ａを機械加工す
る（加工工程９）。なお上述のギヤ２の鋳鉄材料
FCD４５は鋳放しの硬度がビツカース硬さ
（VHN）175の非合金球状黒鉛鋳鉄であり、良好
な加工性を有するが、鋳放し硬度がブリネル硬さ
（BHN）220以上の他の鋳鉄材料を用いる場合に
は歯切り加工性を向上させるため、鋳造工程５と
加工工程６との間において通常のフエライト化焼
鈍を行なうようにすればよい（焼鈍工程７）。 2 to 4 show the manufacturing process of a composite part made by welding cast iron and steel according to an embodiment of the method of the present invention, and this is an example applied to manufacturing a transmission gear for an automobile. When manufacturing the transmission gear 1, which is a composite part, by this method, first the first
A gear 2 as a part and a clutch cone 3 as a second part are manufactured. That is, for gear 2, cast iron material FCD45 (C: 3.60%, Si: 2.55%, Mn, 0.24
%, S: 0.01%, Mg: 0.041%)
A material is cast (casting step 5), and then the gear portion 2b and the cylindrical protrusion 2a, which is the part to be welded, are machined (processing step 6). For clutch cone 3, carburized steel SCr420 is used.
(C: 0.20%, Si: 0.25%, Mn: 0.72%, Cr:
1.13%) by cold forging (forging step 8), and the inner surface 3a of this material 3, which is the part to be welded, is machined (processing step 9). In addition, the cast iron material of gear 2 mentioned above
FCD45 is a non-alloyed spheroidal graphite cast iron with an as-cast hardness of 175 Bitkers hardness (VHN) and has good workability, but other cast iron materials with an as-cast hardness of 220 or higher Brinell hardness (BHN) are used. In this case, in order to improve the gear cutting workability, normal ferritization annealing may be performed between the casting step 5 and the working step 6 (annealing step 7).
次にこのようにして製造したギヤ２とクラツチ
コーン３とを圧入あるいはルーズフイツト嵌合に
よつて結合し（嵌合工程10）、両者の当接部４を
溶接し（溶接工程11）、ミツシヨンギヤ１を製作
する。ここで上述のルーズフイツト嵌合を行なう
場合は、クリアランスをギヤ２突出部２ａの外径
の0.3％以下とするのが好ましい。これは後の熱
処理工程12中にギヤ２の突出部２ａが0.3〜0.35
％膨張するのに対し、クラツチコーン３はほとん
ど変形せず、熱処理後両者が強固に嵌合するから
である。また溶接方法としては、電子ビーム溶
接、レーザビーム溶接あるいはアーク溶接等を用
いればよい。 Next, the gear 2 and the clutch cone 3 manufactured in this way are connected by press fitting or loose fit fitting (fitting process 10), and the contact portion 4 of both is welded (welding process 11). Manufacture. When performing the above-mentioned loose fitting, the clearance is preferably 0.3% or less of the outer diameter of the gear 2 protrusion 2a. This means that during the subsequent heat treatment step 12, the protrusion 2a of the gear 2 will be 0.3 to 0.35.
% expansion, the clutch cone 3 hardly deforms and the two are firmly fitted together after the heat treatment. Further, as a welding method, electron beam welding, laser beam welding, arc welding, etc. may be used.
そして最後にこのようにした製作したミツシヨ
ンギヤ１を熱処理する（熱処理工程12）。即ち、
バツチ炉をプロパン、ブタン、メタン等をキヤリ
アガスで希釈した平衡炭素濃度（カーボンポテン
シヤル）0.80％以上の浸炭性ガス雰囲気、あるい
はこれにアンモニアガスを加えた浸炭窒化性雰囲
気とし、該バツチ炉内においてミツシヨンギヤ１
を850〜950℃の温度で0.5〜10時間加熱し（第４
図の１部参照）、次にソルト浴炉において該ミツ
シヨンギヤ１を220〜300℃の温度で0.1〜３時間
保持した後（第４図のｂ部参照）、空冷すると、
ギヤ２を恒温処理にてベイナイト組織にするオー
ステンパ処理と、クラツチコーン３の表面に浸炭
層を形成しそれを焼入する浸炭焼入処理とを同時
に行なうことができる。 Finally, the thus manufactured transmission gear 1 is heat treated (heat treatment step 12). That is,
The batch furnace is set to a carburizing gas atmosphere with an equilibrium carbon concentration (carbon potential) of 0.80% or more by diluting propane, butane, methane, etc. with a carrier gas, or a carbonitriding atmosphere by adding ammonia gas to this atmosphere. 1
heated at a temperature of 850 to 950℃ for 0.5 to 10 hours (fourth
(see part 1 of the figure), then the transmission gear 1 is held at a temperature of 220 to 300°C for 0.1 to 3 hours in a salt bath furnace (see part b of figure 4), and then air cooled.
It is possible to simultaneously perform an austempering process in which the gear 2 is made into a bainite structure by constant temperature treatment, and a carburizing process in which a carburized layer is formed on the surface of the clutch cone 3 and then hardened.
次に上述のような熱処理を行なう理由について
説明する。 Next, the reason for performing the heat treatment as described above will be explained.
(1) バツチ炉内の平衡炭素濃度を0.8％以上とし
たのは、球状黒鉛鋳鉄製ギヤ２の脱炭防止を図
り、かつクラツチコーン３の浸炭又は浸炭窒化
を行なおうとしたためである。即ち、平衡炭素
濃度が0.8％以下ではギヤ２の表面に脱炭層が
生成されるとともに、クラツチコーン３の浸炭
又は浸炭窒化も不十分となる。非合金球状黒鉛
鋳鉄FCD４５の場合、920℃の温度でオーステ
ナイトに固溶する炭素濃度は0.9〜0.92wt％で
あり、雰囲気中の平衡炭素濃度がこれ以下にな
ると脱炭を生ずる。また加熱温度によつて平衡
炭素濃度を調整する必要もあり、従つて上記非
合金球状黒鉛鋳鉄FCD４５の場合は850℃の加
熱温度で少なくとも0.75％の平衡炭素濃度であ
ればよい。しかし一方で、クラツチコーン３の
表面を浸炭焼入によつて強化する必要上、平衡
炭素濃度が低いのは機能上好ましくなく、0.8
％以下では熱処理後のクラツチコーン３表面の
硬度が増大せず、所望の強度及び耐摩耗性が得
られず、従つて平衡炭素濃度を0.8％以上とし
ているのであるが、より好ましくはこれは0.85
％以上がよい。(1) The reason why the equilibrium carbon concentration in the batch furnace was set to 0.8% or more was to prevent decarburization of the spheroidal graphite cast iron gear 2 and to perform carburization or carbonitriding of the clutch cone 3. That is, if the equilibrium carbon concentration is less than 0.8%, a decarburized layer is formed on the surface of the gear 2, and the carburization or carbonitriding of the clutch cone 3 becomes insufficient. In the case of non-alloyed spheroidal graphite cast iron FCD45, the carbon concentration dissolved in austenite at a temperature of 920° C. is 0.9 to 0.92 wt%, and decarburization occurs when the equilibrium carbon concentration in the atmosphere falls below this. It is also necessary to adjust the equilibrium carbon concentration depending on the heating temperature. Therefore, in the case of the above-mentioned non-alloyed spheroidal graphite cast iron FCD45, the equilibrium carbon concentration should be at least 0.75% at a heating temperature of 850°C. However, on the other hand, since it is necessary to strengthen the surface of the clutch cone 3 by carburizing and quenching, it is functionally undesirable for the equilibrium carbon concentration to be low, and 0.8
% or less, the hardness of the surface of the clutch cone 3 after heat treatment does not increase, and the desired strength and wear resistance cannot be obtained.Therefore, the equilibrium carbon concentration is set to be 0.8% or more, but more preferably this is 0.85%.
% or more is better.
(ii) バツチ炉内での加熱温度を850〜950℃とした
のは、ギヤ２のオーステナイト固溶体の炭素濃
度を0.75〜1.0wt％に調整して続く焼入恒温処
理でギヤ２の組織を良好な耐摩耗性及び疲労強
度を有する針状ベイナイト組織にできるように
すると同時に、クラツチコーン３の表面に対す
る浸炭を容易ならしめるためであり、またさら
に大事なことはこの時前工程11の溶接中に溶接
ビード部４に生成した遊離セメンタイトを分解
するためである。即ち、通常、オーステンパー
処理して強化するギヤ２と浸炭焼入して強化す
るクラツチコーン３とを複合化する場合、それ
ぞれの熱処理を終了した完成品を接合するのが
普通であるが、高炭素材料である鋳鉄を溶接で
接合する場合、溶接ビード部４における遊離セ
メンタイトの生成を避けることができず、接合
強度不足をきたす。そこで本件発明者は850〜
950℃で0.5〜10時間加熱中に遊離セメンタイト
が分解することを知見し、ギヤ２とクラツチコ
ーン３とを溶接した後、熱処理することを考え
ついたものである。以上の説明から分かるよう
に加熱温度が850℃以下ではギヤ２の硬度が増
大せず、耐摩耗性が劣り、又クラツチコーン３
表面への浸炭速度が遅くなつて熱処理に長時間
を要し、さらには溶接接合部４の遊離セメンタ
イトの分解が不十分となる。逆に加熱温度が
950℃以上ではクラツチコーン３の結晶粒が粗
大化し、クラツチコーン３のチヤンフアー３ｂ
がミスシフトによつて加わる衝撃に耐え得なく
なる。(ii) The heating temperature in the batch furnace was set at 850 to 950°C because the carbon concentration of the austenite solid solution of gear 2 was adjusted to 0.75 to 1.0 wt% and the subsequent constant temperature quenching treatment was used to improve the structure of gear 2. This is to form an acicular bainite structure with excellent wear resistance and fatigue strength, and at the same time to facilitate carburization of the surface of the clutch cone 3. More importantly, during the welding process in the previous process 11, This is to decompose free cementite generated in the weld bead portion 4. That is, when combining the gear 2 which is strengthened by austempering and the clutch cone 3 which is strengthened by carburizing and quenching, it is normal to join the finished products after each heat treatment. When joining cast iron, which is a carbon material, by welding, the generation of free cementite in the weld bead 4 cannot be avoided, resulting in insufficient joint strength. Therefore, the inventor of this case is 850~
It was discovered that free cementite decomposed during heating at 950°C for 0.5 to 10 hours, and the idea was to heat-treat the gear 2 and clutch cone 3 after welding them. As can be seen from the above explanation, when the heating temperature is below 850°C, the hardness of gear 2 does not increase, the wear resistance is poor, and the clutch cone 3
The speed of carburizing the surface becomes slow, requiring a long time for heat treatment, and furthermore, the decomposition of free cementite in the welded joint 4 becomes insufficient. On the other hand, the heating temperature
At temperatures above 950°C, the crystal grains of the clutch cone 3 become coarse and the chamfer 3b of the clutch cone 3 becomes coarse.
becomes unable to withstand the impact caused by a misshift.
(iii) バツチ炉内での加熱時間を0.5〜10時間とし
たのは、0.5時間以下の加熱ではクラツチコー
ン３に対する浸炭が十分でなく、浸炭深さ及び
表面硬さが不足し、又溶接接合部４の遊離セメ
ンタイトの分解が不十分となるからであり、逆
に10時間以上の加熱ではクラツチコーン３の結
晶粒の粗大化及び過剰浸炭によつてチヤンフア
ー３ｂの衝撃強度が著しく低下するからであ
る。(iii) The heating time in the batch furnace was set to 0.5 to 10 hours because heating for less than 0.5 hours would not carburize the clutch cone 3 sufficiently, and the carburization depth and surface hardness would be insufficient, and the welded joint This is because the decomposition of free cementite in section 4 becomes insufficient, and conversely, heating for more than 10 hours causes coarsening of the crystal grains of clutch cone 3 and excessive carburization, which significantly reduces the impact strength of clutch cone 3b. be.
(iv) 焼入恒温処理の温度を220〜300℃としたの
は、ギヤ２を耐摩耗性及び耐疲労強度のすぐれ
た針状ベイナイトに変態させるためであるが、
この時クラツチコーン３も同時に硬化する。こ
れはクラツチコーン３の表面が浸炭されている
ためにこの処理によつて強靭性を有する針状ベ
イナイトに変態し、内部は炭素濃度が低く、変
態点Msが400〜450℃と高く、この処理温度で
低炭素マルテンサイト組織に変態するからであ
る。なおクラツチコーン３は変態後も引き続い
て高温にさらされるため、通常行なわれるよう
な焼入れ後の焼戻しは必要としない。また処理
温度が220℃以下ではギヤ２にマルテンサイト
相が析出し、特に疲労強度及び衝撃強度が著し
く低下する。逆に処理浴温度が300℃以上では
ギヤ２及びクラツチコーン３の表面硬さが増大
せず、耐摩耗性が損なわれる。(iv) The temperature of the constant temperature quenching treatment was set at 220 to 300°C in order to transform gear 2 into acicular bainite, which has excellent wear resistance and fatigue resistance.
At this time, the clutch cone 3 is also hardened at the same time. This is because the surface of the clutch cone 3 is carburized, so it transforms into tough acicular bainite through this treatment, and the interior has a low carbon concentration and a high transformation point Ms of 400 to 450°C. This is because it transforms into a low carbon martensitic structure at high temperatures. Note that since the clutch cone 3 is continuously exposed to high temperatures even after transformation, there is no need for tempering after quenching, which is normally performed. Furthermore, if the treatment temperature is below 220°C, a martensite phase will precipitate in the gear 2, resulting in a significant decrease in fatigue strength and impact strength in particular. On the other hand, if the treatment bath temperature is 300° C. or higher, the surface hardness of the gear 2 and clutch cone 3 will not increase, and the wear resistance will be impaired.
(v) 焼入恒温処理時間を0.1〜３時間としたのは、
0.1時間以下ではギヤ２の組織のベイナイト変
態が完了せず、３時間以上では焼入恒温処理を
続けてもそれ以上の機械的性質の改善が得られ
ないからである。(v) The quenching constant temperature treatment time was set to 0.1 to 3 hours because
This is because if the bainite transformation of the structure of the gear 2 is not completed for less than 0.1 hours, and if the constant temperature quenching treatment is continued for more than 3 hours, no further improvement in mechanical properties can be obtained.
また第５図ないし第７図はミツシヨンギヤ１各
部の金属組織を示し、第５図ａ及びｂは、第３図
ｂのギヤ２の内部Ａにおける電子ビーム溶接後で
かつ熱処理前及び熱処理後の組織、第６図ａ及び
ｂは、第３図ｂのクラツチコーン３の表面Ｂにお
ける溶接後で熱処理前及び熱処理後の組織、第６
図ｃは、第３図ｂのクラツチコーン３の内部Ｃに
おける熱処理後の組織、第７図ａ及びｂは溶接ビ
ード部４における溶接後で熱処理前及び熱処理後
の組織を示す。これによれば、溶接後で熱処理前
においては、ギヤ２は第５図ａのように白色のフ
エライトと灰色のパーライトとそれらの中に点在
する球状黒鉛とからなる鋳造組織となつており、
クラツチコーン３は第６図ａのように白色のフエ
ライトと灰色のパーライトとからなる共析組織と
なつており、溶接ビード部４は第７図ａのように
灰色のパーライトと、該パーライト間に生成した
白色の遊離セメンタイトと、微細な黒鉛とからな
る組織となつている。これに対し熱処理後には、
ギヤ２は第５図ｂのように白色の残留オーステナ
イトとその中に生成した針状ベイナイトと球状黒
鉛とからなる組織に変化しており、上記クラツチ
コーン３の表面Ｂは第６図ｂのように残留オース
テナイトと針状ベイナイトとからなる組織に変化
しており、その内部Ｃは第６図ｃのように低炭素
マルテンサイト組織に変化しており、溶接ビード
部４は第７図ｂのように残留オーステナイトと針
状ベイナイトと微細な球状黒鉛とからなる組織に
変化している。このように本方法の熱処理によ
り、溶接時にビード部４に生成した遊離セメンタ
イトは熱処理のオーステナイト化の際に完全に分
解することができ、又ギヤ２は恒温変態によつて
針状ベイナイト組織に、クラツチコーン３は浸炭
焼入・焼戻し組織にすることができる。 5 to 7 show the metal structure of each part of the transmission gear 1, and FIGS. 5a and 5b show the structure of the interior A of the gear 2 in FIG. 3b after electron beam welding and before and after heat treatment. , FIGS. 6a and 6b show the structures before and after heat treatment after welding on the surface B of the clutch cone 3 in FIG. 3b.
Figure c shows the structure of the interior C of the clutch cone 3 in Figure 3b after heat treatment, and Figures 7a and b show the structure of the weld bead 4 after welding before and after heat treatment. According to this, after welding and before heat treatment, the gear 2 has a cast structure consisting of white ferrite, gray pearlite, and spheroidal graphite scattered therein, as shown in FIG. 5a,
The clutch cone 3 has a eutectoid structure consisting of white ferrite and gray pearlite as shown in Figure 6a, and the weld bead 4 has gray pearlite and a gap between the pearlites as shown in Figure 7a. The structure consists of white free cementite and fine graphite. On the other hand, after heat treatment,
The gear 2 has changed to a structure consisting of white retained austenite, acicular bainite and spherical graphite formed therein, as shown in Fig. 5b, and the surface B of the clutch cone 3 has a structure as shown in Fig. 6b. The structure has changed to a structure consisting of retained austenite and acicular bainite, and the interior C has changed to a low carbon martensitic structure as shown in Fig. 6c, and the weld bead portion 4 has changed to a structure consisting of retained austenite and acicular bainite as shown in Fig. 7b. The structure has changed to consist of residual austenite, acicular bainite, and fine spheroidal graphite. As described above, by the heat treatment of this method, the free cementite generated in the bead portion 4 during welding can be completely decomposed during the heat treatment to austenite, and the gear 2 has an acicular bainite structure due to isothermal transformation. The clutch cone 3 can have a carburized, quenched and tempered structure.
また第８図は恒温処理温度に対する溶接ビード
部４の機械的性質の変化を実験により求めた結果
を示している。これによれば、溶接ビード部４の
引張強さは図中実線で示すように、恒温処理温度
が高くなるに伴つて次第に増大し、ほぼ250℃で
最高値約150Kg・f/mm2に達し、その後滑らかに減少
している。また溶接ビード部４の伸びは図中１点
鎖線で示すように、温度が高くなるに伴つて単調
に増加し、300℃でほぼ４％になる。さらに溶接
ビード部４の硬度は図中２点鎖線で示すように、
温度が高くなるに伴つてロツクウエル硬さ
HRc60ぐらいから40ぐらいまで単調に減少して
いる。このような本方法の熱処理により、溶接ビ
ード部４は引張強さ120〜150Kg・f/mm2、伸び２〜
５％となり、球状黒鉛鋳鉄母材と基本的に同等の
機械的性質を発揮し、これにより接合部の強度が
確保される。 Further, FIG. 8 shows the results of experiments on changes in the mechanical properties of the weld bead portion 4 with respect to the constant temperature treatment temperature. According to this, the tensile strength of the weld bead 4 gradually increases as the constant temperature treatment temperature increases, reaching a maximum value of approximately 150 Kg・f/mm 2 at approximately 250°C, as shown by the solid line in the figure. , and then decreases smoothly. Further, the elongation of the weld bead portion 4 increases monotonically as the temperature increases, and reaches approximately 4% at 300°C, as shown by the dashed line in the figure. Furthermore, the hardness of the weld bead portion 4 is as shown by the two-dot chain line in the figure.
Rockwell hardness increases as temperature increases
HRc decreases monotonically from around 60 to around 40. Through the heat treatment of this method, the weld bead portion 4 has a tensile strength of 120 to 150 Kg・f/mm 2 and an elongation of 2 to
5%, exhibiting mechanical properties basically equivalent to those of the spheroidal graphite cast iron base material, thereby ensuring the strength of the joint.
またミツシヨンギヤ１各部の熱処理前及び熱処
理後の硬度を測定したところ、熱処理前には、上
記ギヤ２の内部Ａにおいては、ビツカース硬さ
（VHN）175、溶接ビード部４においては
VHN620、上記クラツチコーン３の表面Ｂにお
いてはVHN155であつたが、熱処理後には、ギ
ヤ２はVHN492、溶接ビード部４はVHN480（ロ
ツクウエル硬さHRc47）、上記クラツチコーン３
の内部ＣにおいてはVHN359となつた。さらに
熱処理後のクラツチコーン３の表面Ｂの位置にお
いて該表面からの焼入深さを見るため表面からの
各深さにおける硬度を測定したところ、第９図に
示す結果が得られた。これによれば、表面から
0.1mmのところで最高の硬度VHN750となり、又
表面から0.33mmまでの部分がVHN513以上となつ
て0.33mmの浸炭深さが得られた。このように本方
法の熱処理により、クラツチコーン３の十分な浸
炭焼入深さと、通常の浸炭焼入処理と同等の硬度
とを得ることができる。 Furthermore, when we measured the hardness of each part of the transmission gear 1 before and after heat treatment, we found that before heat treatment, the internal A of the gear 2 had a Vickers hardness (VHN) of 175, and the weld bead 4 had a Vickers hardness of 175.
VHN620, the surface B of the clutch cone 3 was VHN155, but after heat treatment, the gear 2 was VHN492, the weld bead 4 was VHN480 (Rockwell hardness HRc47), and the clutch cone 3
In the internal C of , it became VHN359. Further, the hardness at each depth from the surface was measured at the position of surface B of the clutch cone 3 after the heat treatment in order to check the quenching depth from the surface, and the results shown in FIG. 9 were obtained. According to this, from the surface
The highest hardness was VHN750 at 0.1mm, and the part from the surface to 0.33mm was VHN513 or higher, giving a carburizing depth of 0.33mm. As described above, by the heat treatment of the present method, it is possible to obtain a sufficient depth of carburization and quenching of the clutch cone 3 and a hardness equivalent to that of ordinary carburization and quenching.
以上のような本実施例の製造方法では、ミツシ
ヨンギヤを鋳鉄と鋼とからなる複合部品としたの
で、高価な鋼の量を低減でき、製造コストが安価
となり、しかも軽量化を達成できる。またギヤに
鋳鉄材料を用いているので、ギヤの熱処理変形及
びギヤノイズの発生を軽減できる。さらにギヤ及
びクラツチコーンの熱処理を同時に行なつてお
り、しかも従来のような浸炭焼入れ後の焼戻し処
理が不要となるので、熱処理作業を簡単化でき、
これによつても製造コストを安価にできる。 In the manufacturing method of this embodiment as described above, since the transmission gear is a composite part made of cast iron and steel, the amount of expensive steel can be reduced, manufacturing cost can be reduced, and weight reduction can be achieved. Furthermore, since cast iron material is used for the gear, heat treatment deformation of the gear and generation of gear noise can be reduced. Furthermore, the gear and clutch cone are heat-treated at the same time, and the conventional tempering process after carburizing and quenching is not required, which simplifies the heat-treating process.
This also makes it possible to reduce manufacturing costs.
また本製造方法では、溶接ビード部に生成した
遊離セメンタイトを分解することができ、大きな
接合強度が得られる。またギヤをベイナイト組織
に、クラツチコーンを浸炭焼入・焼戻し組織にし
たので、ミツシヨンギヤの強靭化を達成でき、信
頼性を向上できる。 Further, in this manufacturing method, free cementite generated in the weld bead can be decomposed, and a large joint strength can be obtained. Furthermore, since the gear has a bainitic structure and the clutch cone has a carburized and quenched structure, the transmission gear can be made tougher and reliability can be improved.
なお上記実施例では自動車用ミツシヨンギヤの
製造方法について説明したが、本発明は勿論ミツ
シヨンギヤ以外の鋳鉄と鋼の複合部品の製造に適
用できるものである。 In the above embodiment, a method for manufacturing a transmission gear for an automobile has been described, but the present invention can of course be applied to manufacturing composite parts of cast iron and steel other than transmission gears.
以上のように本発明によれば、鋳鉄製の第１部
品と浸炭鋼製の第２部品とを電子ビーム溶接等に
よつて接合して複合部品を製作した後、それを浸
炭雰囲気中で850〜950℃にて0.5〜10時間加熱し
た後220〜300℃にて0.1〜３時間保持することに
よつて第１部品を恒温処理にてベイナイト組織に
するオーステンパ処理と第２部品を浸炭焼入する
処理とを同時にできるようにしたので、大きな接
合強度を得ることができるとともに、母材の強靭
化を達成でき、しかも熱処理が１回ですむという
効果を得ることができる。 As described above, according to the present invention, after manufacturing a composite part by joining a first part made of cast iron and a second part made of carburized steel by electron beam welding, etc., The first part is heated to 950℃ for 0.5 to 10 hours and then held at 220 to 300℃ for 0.1 to 3 hours to make the first part a bainite structure by constant temperature treatment.The second part is carburized and quenched. Since these treatments can be performed simultaneously, it is possible to obtain a large bonding strength, to strengthen the base material, and to achieve the effect that only one heat treatment is required.
第１図ａ及びｂはそれぞれ従来の自動車用ミツ
シヨンギヤの側面図及び断面図、第２図は本発明
の一実施例方法による自動車用ミツシヨンギヤの
製造工程を示す図、第３図ａ及びｂはそれぞれ上
記方法により製造された自動車用ミツシヨンギヤ
の側面図及び要部断面図、第４図は上記実施例の
熱処理における温度の時間的変化を示す図、第５
図ないし第７図はそれぞれ上記自動車用ミツシヨ
ンギヤ各部の金属組織の顕微鏡写真であり、第５
図ａ及びｂはそれぞれギヤ２の溶接後でかつ熱処
理及び熱処理後の金属組織の顕微鏡写真、第６図
ａ及びｂはそれぞれクラツチコーン３表面の溶接
後でかつ熱処理前及び熱処理後の金属組織の顕微
鏡写真、第６図ｃはクラツチコーン３内部の熱処
理後の金属組織の顕微鏡写真、第７図ａ及びｂは
それぞれ溶接ビード部４の溶接後でかつ熱処理前
及び熱処理後の金属組織の顕微鏡写真、第８図は
恒温処理温度に対する上記自動車用ミツシヨンギ
ヤの溶接ビード部の引張強さ、伸び及び硬度の関
係を示す図、第９図は上記自動車用ミツシヨンギ
ヤにおけるクラツチコーン３の浸炭深さの測定結
果を示す図である。
１…ミツシヨンギヤ（複合部品）、２…ギヤ
（第１部品）、３…クラツチコーン（第２部品）。
FIGS. 1a and 1b are a side view and a sectional view of a conventional automobile transmission gear, respectively. FIG. 2 is a diagram showing the manufacturing process of an automobile transmission gear according to an embodiment of the present invention. FIGS. A side view and a cross-sectional view of the main parts of an automobile transmission gear manufactured by the above method, FIG. 4 is a diagram showing temporal changes in temperature during the heat treatment of the above example, and FIG.
Figures 7 through 7 are microscopic photographs of the metal structure of each part of the automobile transmission gear, respectively.
Figures a and b are micrographs of the metal structure of gear 2 after welding and heat treatment, and Figures 6 a and b are micrographs of the metal structure of clutch cone 3 surface after welding and before and after heat treatment, respectively. FIG. 6c is a micrograph of the metal structure inside the clutch cone 3 after heat treatment, and FIGS. 7a and b are microphotographs of the metal structure of the weld bead portion 4 after welding, before and after heat treatment, respectively. , Fig. 8 is a diagram showing the relationship between the tensile strength, elongation, and hardness of the weld bead of the above-mentioned automobile transmission gear with respect to constant temperature treatment temperature, and Fig. 9 is a diagram showing the measurement results of the carburization depth of the clutch cone 3 in the above-mentioned automobile transmission gear. FIG. 1...Mission gear (composite part), 2...Gear (first part), 3...Clutch cone (second part).
Claims (1)
法であつて、鋳鉄材料にて第１部品を鋳造した後
該第１部品の溶接接合すべき部分を機械加工する
一方、浸炭鋼製の第２部品の溶接接合すべき部分
を機械加工し、この機械加工された第１部品と第
２部品の両者の溶接接合すべき部分を当接させて
溶接して複合部品を製作し、この複合部品を浸炭
雰囲気内で850〜950℃にて0.5〜10時間加熱した
後220〜300℃にて0.1〜３時間保持し第１部品を
恒温処理にてベイナイト組織にするオーステンパ
処理と第２部品の表面に浸炭層を形成しそれを焼
入する浸炭焼入処理とを同時に行なうことを特徴
とする鋳鉄と鋼とを溶接してなる複合部品の製造
方法。1. A method for manufacturing a composite part made by welding two parts, in which a first part is cast with cast iron material, and then a part of the first part to be welded is machined, while a second part made of carburized steel is machined. The parts of the two parts to be welded together are machined, and the parts of the machined first part and the second part that are to be welded are brought into contact and welded to produce a composite part. is heated for 0.5 to 10 hours at 850 to 950℃ in a carburizing atmosphere, and then held at 220 to 300℃ for 0.1 to 3 hours to austemper the first part to a bainitic structure by constant temperature treatment and the surface of the second part. A method for manufacturing a composite part made by welding cast iron and steel, characterized by simultaneously performing a carburizing treatment that forms a carburized layer and hardens it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18568982A JPS5974275A (en) | 1982-10-20 | 1982-10-20 | Manufacture of composite member consisting of welded cast iron and steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18568982A JPS5974275A (en) | 1982-10-20 | 1982-10-20 | Manufacture of composite member consisting of welded cast iron and steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5974275A JPS5974275A (en) | 1984-04-26 |
| JPH0210223B2 true JPH0210223B2 (en) | 1990-03-07 |
Family
ID=16175137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18568982A Granted JPS5974275A (en) | 1982-10-20 | 1982-10-20 | Manufacture of composite member consisting of welded cast iron and steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5974275A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3637447A1 (en) * | 1985-11-05 | 1987-05-07 | Nippon Telegraph & Telephone | SURFACE TREATED MAGNESIUM OR MAGNESIUM ALLOY AND METHOD FOR SURFACE TREATING MAGNESIUM OR MAGNESIUM ALLOY |
| JP2007170622A (en) * | 2005-12-26 | 2007-07-05 | Ｇｋｎ ドライブライン トルクテクノロジー株式会社 | Joint structure of torque transmission member, joining method for torque transmission member, and power transmission device using them |
| JP5372871B2 (en) | 2010-08-27 | 2013-12-18 | 株式会社エフ・シー・シー | Integral member and manufacturing method thereof |
| CN102796852B (en) * | 2012-07-16 | 2014-07-02 | 鑫光热处理工业(昆山)有限公司 | Carburizing reinforced isothermal quenching workpiece and processing method thereof |
| CN102941392A (en) * | 2012-11-15 | 2013-02-27 | 大连船舶重工集团装备制造有限公司 | Method suitable for welding low alloy high strength plate and low alloy steel casting |
-
1982
- 1982-10-20 JP JP18568982A patent/JPS5974275A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5974275A (en) | 1984-04-26 |
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