JPS60245721A - Heat treatment of steel material - Google Patents
Heat treatment of steel materialInfo
- Publication number
- JPS60245721A JPS60245721A JP10233884A JP10233884A JPS60245721A JP S60245721 A JPS60245721 A JP S60245721A JP 10233884 A JP10233884 A JP 10233884A JP 10233884 A JP10233884 A JP 10233884A JP S60245721 A JPS60245721 A JP S60245721A
- Authority
- JP
- Japan
- Prior art keywords
- heating
- heat treatment
- point
- steel material
- temperature
- 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.)
- Pending
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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
-
- 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
- C21D1/34—Methods of heating
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)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
Description
【発明の詳細な説明】
く技術分野〉
この発明は、鋼材の細粒化熱処理方法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method of heat treatment for refining steel materials.
く背景技術〉
一般に、構造用高強度継目無鋼管等の製造に当っては、
熱間加工終了後の鋼材を−ＨＡｒＩ点以下の温度にまで
冷却した後再度オーステナイト域にまで加熱すると言う
″オーステナイト比熱処理″が行われているが、近年、
このようなオーステナイト化熱処理時の加熱ヲ゛急速加
熱″にすると、オーステナイト粒が微細ＩＣなフ、靭性
の向上がもたらされることが知られるようになった。ま
た。Background technology> In general, when manufacturing high-strength seamless steel pipes for structural use,
"Austenite specific heat treatment" is carried out in which the steel material after hot working is cooled down to a temperature below the -HArI point and then heated again to the austenite region, but in recent years,
It has become known that if the heating during such austenitizing heat treatment is carried out at "rapid heating", the austenite grains become fine IC and the toughness is improved.
この急速加熱手段としてハ″誘導加熱法″が好適である
との報告もなされている（特開昭５８−９１１２３号公
報）。It has also been reported that the "induction heating method" is suitable as this rapid heating means (Japanese Unexamined Patent Publication No. 58-91123).
しかしながら、熱処理の際に急速加熱を行うと被加熱鋼
材に加熱ムラを生じやすく、そのため、上述のようなオ
ーステナイト化熱処理を急速加熱で実施した場合には、
所望の均一な組織全組るのが非常に困難であるとの不都
合を容認せざるを得なかった。However, if rapid heating is performed during heat treatment, uneven heating tends to occur in the heated steel material. Therefore, when the austenitizing heat treatment as described above is performed by rapid heating,
We had to accept the inconvenience that it is very difficult to assemble the desired uniform structure.
そして、この傾向は常温付近のような低い温度域の場合
に特に著しいので、常温からＡＣ３点以上の温度域１で
急速加熱するようなときには太＠な問題となっていたの
である。Since this tendency is particularly noticeable in a low temperature range such as around room temperature, it has become a serious problem when rapidly heating from room temperature to temperature range 1 of 3 AC points or more.
捷た、ビード余盛付管や偏肉管等では、その肉厚が一様
でないので加熱温度や加熱速度にバラツキを生じ易くて
加熱ムラが出易い上、被カロ熱材の肉厚バラツキで生じ
る加熱温度差は累積される傾向にあることから急速加熱
の温度範囲が大きいほど加熱ムラが顕著となシ、従って
、急速加熱で均一な組織を得るのは一層困難なことであ
った。Since the wall thickness of twisted pipes with bead reinforcement and uneven wall thickness is not uniform, it is easy to cause variations in heating temperature and heating rate, resulting in uneven heating. Since the heating temperature difference that occurs tends to accumulate, the wider the temperature range of rapid heating, the more pronounced the heating unevenness becomes. Therefore, it has been more difficult to obtain a uniform structure by rapid heating.
更に、急速加熱手段として誘導加熱方式全採用した場合
Ｖｃｌ−ｊ、加熱コストが通常の燃焼式加熱炉全使用し
た場合よりも相当に上昇すると言う問題もあった。Furthermore, there is a problem in that when all induction heating systems are employed as rapid heating means, the heating cost (Vcl-j) increases considerably compared to when all ordinary combustion heating furnaces are used.
〈発明の目的〉
この発明が目的とするところは、上述のような問題点を
解消し、被処理材の形態等に左右されることなく、均一
微細な鋼材組織全安定かつコスト安く実現し得る鋼材の
細粒化熱処理方法全提供することにある。<Objective of the Invention> The object of this invention is to solve the above-mentioned problems and to realize a uniform, fine steel structure completely stable and at low cost, regardless of the form of the material to be treated. The purpose of the present invention is to provide a complete method for grain refining heat treatment of steel materials.
〈構成〉
本発明者等は、この発明′ｆｆ：なすに当ｐ１試行錯誤
全繰ｐ返しながら上述の如き観点からの研究を行った結
果、まず、
［鋼材の細粒化熱処理の際、結晶粒の微細化に寄与する
急速加熱温度領域ＵＡＣｘ点以上の領域でしかない」
との思いもかけない知見を得るに至ったのである。<Structure> As a result of research from the above-mentioned point of view through repeated trial and error, the inventors of the present invention discovered that [during grain refining heat treatment of steel materials, crystallization They came to the unexpected finding that "the rapid heating temperature range, which contributes to grain refinement, is only in the region above the UACx point."
第１図は、ＡＩＳ工４１３０相当の鋼材について、常温
から９２０℃までを等速で加熱した場合のオーステナイ
ト粒度に及ぼす加熱速度の影響を、２種の加熱保持時間
の下で調査した結果を示すグラフであシ、一方％第２図
は、同様鋼材について。Figure 1 shows the results of investigating the effect of heating rate on austenite grain size when steel material equivalent to AIS grade 4130 is heated from room temperature to 920°C at a constant rate under two types of heating holding times. On the other hand, % Figure 2 is for steel materials as well.
常温からＡＣＩ点直下１で全２レベルの加熱速度で加熱
し、その後は等速で加熱（，５た場合のオースブナイト
粒度に及ぼす「ＡＣ１点以上の領域」の加熱速度の影響
を示すグラフである。This is a graph showing the influence of the heating rate in the ``area of AC 1 point or more'' on the ausbunite grain size when heating from room temperature to just below the ACI point 1 at two levels of heating rate, and then heating at a constant rate (, 5). .
第１図及び第２図からも、若干の保持時間の差やＡＣＩ
点未満の温度領域での加熱速度の差がオーステナイト粒
度に影響を与えることは殆んどないが、鋼材のオーステ
ナイト粒度はｒＡｃＩ点以上の温度領域での加熱速度」
によって決定され、しかもその領域での加熱速度が１℃
／ｓｅｅ以上になると顕著なオーステナイト粒細粒化傾
向を示すことがわかる。From Figures 1 and 2, there is a slight difference in retention time and ACI.
The difference in heating rate in the temperature range below the rAcI point has little effect on the austenite grain size, but the difference in austenite grain size in steel materials depends on the heating rate in the temperature range above the rAcI point.
, and the heating rate in that region is 1℃.
It can be seen that when the austenite grain size exceeds /see, a remarkable tendency towards austenite grain refinement is exhibited.
この発明に、上記知見に基づいてなされたものであり。This invention was made based on the above knowledge.
鋼材を熱間加工後、一旦Ａｒ１点以下の温度に冷却して
からＡＣ３点以上オーステナイト結晶粒粗大化温度未満
の温度域にまで再加熱する熱処理方法において、再加熱
の際、ＡＣ３点に至る温度までは１．０℃／ ５８０未
満の加熱速度で徐加熱し、ＡＣ１点以上の温度域ニ１．
０℃／ｓｅｃ以上の加熱速度で急加熱することによシ、
急加熱の温度範囲を極力狭くし、均一微細な鋼材組織全
実現する点、
に特徴全有するものである。In a heat treatment method in which a steel material is once cooled to a temperature below Ar1 point after hot working, and then reheated to a temperature range of AC3 point or higher and below the austenite grain coarsening temperature, the temperature that reaches AC3 point during reheating Heat slowly at a heating rate of less than 1.0°C/580℃ until temperature range is 1.
By rapid heating at a heating rate of 0°C/sec or more,
It has the following characteristics: the temperature range of rapid heating is made as narrow as possible, and a uniform and fine steel structure is achieved throughout.
なお、この発明の熱処理方法においてＡｃ１点未満の温
度領域における鋼材の加熱速度全り、０℃／就未満と定
めたのに、この領域での加熱速度が１（）℃／ｓｅｃ以
上になると加熱ムラが出易くなって均一組織を得るのが
困難となるからであり、一方、Ａｃ】点以上の温度領域
における鋼材の加熱速度ヲ１．０℃／ ｓｅｃ以上と定
めたの汀、第１図及び第２図からも明らかなように、カ
ロ熱速度が１，０℃／渡を下回ると所望の細粒化が達成
できなくなるからであるが、好ましくは２．５℃／ｓｅ
ｃ以上の加熱速度を確保するのが良い。In addition, in the heat treatment method of the present invention, the heating rate of the steel material in the temperature range below the Ac1 point is set to be less than 0°C/sec, but if the heating rate in this area exceeds 1()°C/sec, the heating rate is This is because unevenness tends to occur and it becomes difficult to obtain a uniform structure.On the other hand, the heating rate of the steel material in the temperature range above the AC point was determined to be 1.0°C/sec or more. As is clear from FIG. 2, if the Calothermal rate is less than 1.0°C/sec, the desired grain refinement cannot be achieved, but it is preferably 2.5°C/sec.
It is better to ensure a heating rate of c or more.
そして、加熱速度：１．０℃／ｓｅｃ未満の徐加熱は。And heating rate: slow heating of less than 1.0°C/sec.
例えばバレル型炉、ウオーキングビーム型炉又はローラ
・・−ス型炉等の燃焼式加熱炉によって行うのが経済的
にも有利である。これに対して、加熱速度：１．０℃／
就以上の急加熱は、作業性及び組繊細粒化効果の上から
誘導加熱装置によって行うのが好ましい。For example, it is economically advantageous to use a combustion heating furnace such as a barrel furnace, a walking beam furnace, or a roller furnace. On the other hand, heating rate: 1.0℃/
The rapid heating is preferably carried out using an induction heating device from the viewpoint of workability and the effect of forming fine grains.
また、この発明の熱処理方法の対象とされる鋼阿は、そ
の種類が格別に制限されるものでないことは言うまでも
ない。Further, it goes without saying that the type of steel that is subjected to the heat treatment method of the present invention is not particularly limited.
第３図は、この発明の熱処理全実施するのに好適な、バ
レル型燃焼炉と誘導加熱装置とを組合せた熱処理装置の
概略配置図であり、符号１１１’ｌｊ搬送装置、２にバ
レル型燃焼加熱炉、３は誘導加熱装置、４は移動台車、
そして５に焼入れ装置をそれぞれ示している。FIG. 3 is a schematic layout diagram of a heat treatment apparatus which is a combination of a barrel-type combustion furnace and an induction heating apparatus and is suitable for carrying out the entire heat treatment of the present invention. A heating furnace, 3 an induction heating device, 4 a mobile cart,
5 shows the hardening equipment.
この第３図に示される熱処理装置において、熱間ヵＤ工
が終了し、変態にょる細粒化効果を狙ってＡ’ｒ１点以
下の温度に冷却された鋼材は、ますカロ熱コストの小さ
いバレル型燃焼加熱炉２にて加熱速度；１．Ｏ℃／ｓｅ
ｃ未満の徐加熱が施され、 Ａｃｌ変態点（−膜中炭素
鋼でｉ”ｌニア３０’Ｃ程度）付近まで均一に昇温され
る。続いて、被加熱鋼材は前記バレル型燃焼加熱炉２の
直後に配置された誘導加熱装置３ｖＣて目標の温度才で
急速加熱され、焼入れ装置５により焼入れ処理されて、
比較的低コストの下に高靭性細粒鋼となるのである。In the heat treatment equipment shown in Fig. 3, the steel material that has been cooled to a temperature below the A'r1 point with the aim of achieving a grain refinement effect due to transformation after the hot CAD process has been completed has a lower calothermal cost. Heating rate in barrel type combustion heating furnace 2;1. O℃/se
The steel material to be heated is subjected to gradual heating to a temperature of less than C, and the temperature is uniformly raised to around the ACl transformation point (about 30'C for carbon steel in the film).Subsequently, the steel material to be heated is heated in the barrel-type combustion heating furnace. It is rapidly heated to a target temperature by an induction heating device 3V placed immediately after the heating device 2, and is hardened by a hardening device 5.
This results in high-toughness, fine-grained steel at relatively low cost.
この場合、燃焼式加熱炉を、被加熱材の違いに応じてウ
オーキングビーム型やローラハース型等に替えて良いこ
とはもちろんである。In this case, it goes without saying that the combustion type heating furnace may be replaced with a walking beam type, a roller hearth type, etc. depending on the material to be heated.
なお、第３図で示される装置では、誘導加熱装置３を移
動台車４上に載置してあシ、他種工程の熱処理時に、同
じく移動台車４上に載置されたバレル型燃焼加熱炉２と
交換できるようになっている。In the apparatus shown in FIG. 3, the induction heating device 3 is placed on a moving cart 4, and during heat treatment in other processes, a barrel-type combustion heating furnace also placed on the moving cart 4 is used. It can be exchanged for 2.
〈総括的な効果〉
上述のように、この発明によれば、鋼材のオーステナイ
ト化熱処理における急速加熱の温度範囲を小さくするこ
とができ、従って、微細で均一な鋼材組織全、経済的［
、かつ安定して実現することが可能となるなど、工業上
有用な効果がもたらされるのである。<Overall Effects> As described above, according to the present invention, it is possible to reduce the temperature range of rapid heating in the austenitizing heat treatment of steel materials, and therefore, it is possible to reduce the temperature range of rapid heating in the austenitizing heat treatment of steel materials.
This brings about industrially useful effects, such as making it possible to achieve this in a stable manner.
第１図に、等速加熱の場合の、オーステナイト粒度に及
ぼす加熱速度の影響を示すグラフ、第２図は、常温から
Ａｃｔ点直下までを２レベルの加熱速度で加熱し、その
後は等速で加熱した場合の、オーステナイト粒度に及ぼ
すＡｃ１点以上の領域での加熱速度の影響を示すグラフ
。
第３図は１本発明の方法を実施するための熱処理装置の
例を示す概略図である。
図面において、
１・・・搬送装置、
２・・・バレル型燃焼加熱炉、
３・・誘導加熱装置、４・・・移動台車、５・・・焼入
れ装置。
出願人 住友螢属工業株式会社
代理人 富 １）和 夫ほか１名
学１府
力１［’ｊＬＪＥ （’Ｃ／ｓｅｃ ）差２ＺFigure 1 is a graph showing the effect of heating rate on austenite grain size in the case of uniform heating, and Figure 2 is a graph showing the effect of heating rate on austenite grain size in the case of constant heating. Graph showing the influence of heating rate on austenite grain size in the region of Ac 1 point or higher when heated. FIG. 3 is a schematic diagram showing an example of a heat treatment apparatus for carrying out the method of the present invention. In the drawings, 1...Transfer device, 2...Barrel type combustion heating furnace, 3...Induction heating device, 4...Moving trolley, 5...Quenching device. Applicant Sumitomo Hozoku Industries Co., Ltd. Agent Tomi 1) Kazuo and 1 other person Academic 1 Faculty 1 ['jLJE ('C/sec) Difference 2Z
Claims (3)
却してからＡＣ３点以上オーステナイト結晶粒粗大化温
度未満の温度域にまで再加熱する熱処理方法において、
再加熱の際、ＡＣ３点に至る温度までは１．０℃／渡未
満の加熱速度で徐加熱し、ＡＣ４点以上の温度域は１．
０℃／ｓｅｃ以上の加熱速度で急加熱することを特徴と
する鋼材の熱処理方法。(1) In a heat treatment method in which after hot working a steel material, it is once cooled to a temperature below the ArI point and then reheated to a temperature range of 3 AC points or higher and below the austenite grain coarsening temperature,
When reheating, heat slowly at a heating rate of less than 1.0°C/wad until the temperature reaches AC 3, and at a temperature of 1.
A method for heat treatment of steel materials, characterized by rapidly heating at a heating rate of 0° C./sec or more.
項記載の鋼材の熱処理方法。(2) Claim 1 in which slow heating is performed in a combustion heating furnace
Heat treatment method for steel materials described in Section 2.
項又は第２項記載の鋼材の熱処理方法。(3) Claim 1 in which rapid heating is performed using an induction heating device
2. The method for heat treatment of steel according to item 2 or item 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10233884A JPS60245721A (en) | 1984-05-21 | 1984-05-21 | Heat treatment of steel material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10233884A JPS60245721A (en) | 1984-05-21 | 1984-05-21 | Heat treatment of steel material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60245721A true JPS60245721A (en) | 1985-12-05 |
Family
ID=14324718
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10233884A Pending JPS60245721A (en) | 1984-05-21 | 1984-05-21 | Heat treatment of steel material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60245721A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05112809A (en) * | 1991-07-26 | 1993-05-07 | Mitsubishi Nagasaki Kiko Kk | Production of ultrahigh strength steel |
| EP1678335A1 (en) | 2003-10-10 | 2006-07-12 | Tenaris Connections AG | Low carbon alloy steel tube having ultra high strength and excellent toughnes at low temperature and method of manufacturing the same |
-
1984
- 1984-05-21 JP JP10233884A patent/JPS60245721A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05112809A (en) * | 1991-07-26 | 1993-05-07 | Mitsubishi Nagasaki Kiko Kk | Production of ultrahigh strength steel |
| EP1678335A1 (en) | 2003-10-10 | 2006-07-12 | Tenaris Connections AG | Low carbon alloy steel tube having ultra high strength and excellent toughnes at low temperature and method of manufacturing the same |
| KR101178954B1 (en) | 2003-10-10 | 2012-08-31 | 테나리스 커넥션즈 아.게. | Low carbon alloy steel tube having ultra high strength and excellent toughness at low temperature and method of manufacturing the same |
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