JPS6348924B2 - - Google Patents
Info
- Publication number
- JPS6348924B2 JPS6348924B2 JP58027891A JP2789183A JPS6348924B2 JP S6348924 B2 JPS6348924 B2 JP S6348924B2 JP 58027891 A JP58027891 A JP 58027891A JP 2789183 A JP2789183 A JP 2789183A JP S6348924 B2 JPS6348924 B2 JP S6348924B2
- Authority
- JP
- Japan
- Prior art keywords
- sleeve
- heat treatment
- heating
- holding
- cooling
- 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
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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/38—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for roll bodies
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)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
- Heat Treatment Of Articles (AREA)
Description
本発明は可変クラウンロール用スリーブの熱処
理方法、特に外表面を高硬度とし、内面を高靭
性、高強度とする２段階熱処理方法に関する。
可変クラウンロールとは、ロールスリーブ内面
より油圧をかけてロールスリーブ表面の半径方向
の寸法を変化させることのできる、例えば本出願
人が先に出願した特願昭57−78590号に開示され
ている如きロールである。この種のロールは、ロ
ール本来の特性として表面の高硬度、耐摩耗、耐
スポーリング性のほか、スリーブにかかる圧油に
応じて十分屈曲すると共に、圧油力に対し十分な
強度を保持すべく高強度と高靭性が必要である。
従来、スリーブ式圧延ロールのスリーブは炭素
0.45〜1.00％、珪素0.10〜1.00％、マンガン0.15〜
1.00％、クロム1.50〜8.00％、モリブデン0.05〜
2.0％、残部鉄および不可避不純物からなる組成
の鋼で製作し、慣用の１次熱処理を施したのち、
以下のような２次熱処理を施工していた。
すなわち、スリーブの両端に鋼板で蓋を行い、
間隙部を不定形耐火材等でシールした後、直火式
加熱炉中で回転させながら急速加熱を行い外表面
温度が800〜950℃の範囲に達した後急冷する。次
いで、該スリーブを100〜650℃の範囲に加熱後、
空冷するものである。
しかしながら、従来技術においてはスリーブ表
面には十分な硬度が得られるが内部は靭性を含む
機械的性質が十分ではなく、可変クラウンロール
のスリーブとして使用するには圧油に対する強度
特性が十分でないという欠点があつた。
（発明が解決しようとする問題点）
本発明は、上記の従来技術の問題を解決するこ
とを目的とし、更に詳細には、表面硬度とともに
内部の強度、靭性も十分に高い可変クラウンロー
ル用のスリーブを提供することを目的とする。
（問題点を解決するための手段）
本発明は、上記のような素材で製造された可変
クラウンロール用スリーブの熱処理方法に於い
て、１次熱処理として該スリーブを800〜950℃の
範囲に加熱保持した後、油焼入れし、次いで500
〜700℃の範囲に加熱保持した後に油冷し、２次
熱処理として、該スリーブ内面を冷却しながら外
表面を800〜950℃の範囲に高速加熱保持後に急冷
し、次いで該スリーブを100〜650℃の範囲に加熱
後、空冷することからなることを特徴とする上記
熱処理方法である。
（作用）
本発明においてスリーブの材質を前記のように
限定する理由を以下に述べる。
炭素は焼入性を上げさらにモリブデン、クロム
炭化物による析出硬化をもたらすための基本的添
加元素である。しかし、炭素が多すぎると初析炭
化物が粗大化し靭性の低下をまねくため1.00％以
下とし、低すぎると十分な焼戻し硬さが得られな
いため0.45％以上とした。
珪素は、製鋼上の脱酸剤として含有され0.10％
未満では十分な脱酸効果が得られず1.00％を超え
ると、脱酸剤として過剰であり実用的でない。
マンガンは焼入性を高めフエライト生成を防
ぎ、また硫黄との間にMnS系介在物を形成し、
被削性を付与するため不可欠の含有元素である。
多すぎると被削性を低下させるので1.00％以下と
し、低すぎると上記の効果が得られないため0.15
％以上とした。
クロムは焼入性を高め、また焼戻し時炭化物析
出をもたらし析出硬化における硬さを調整する。
多すぎるとフエライト生成をまねくので8.0％以
下とし低すぎると上記効果が得られないので1.5
％以上とする。
モリブデンは焼戻し時炭化物を析出し、析出硬
化をもたらすための元素である。多すぎると被削
性、靭性低下をまねくので2.00％以下とし低すぎ
ると上記効果が得られないので0.050％以上とす
る。
熱処理を２回に分けて行う理由は以下のとおり
である。
１次熱処理は素材全体の調質を目的とし、素材
に所定の強度靭性を付与するものである。
２次熱処理は素材表面部近傍を再度オーステナ
イト状態まで加熱後油冷し、１次熱処理時の焼戻
し温度より低い温度で焼戻しを行うことにより、
表面部に高硬度を付与するものである。
１次および２次熱処理時の焼入加熱温度を800
〜950℃とする理由は800℃未満では十分なオース
テナイト化が得られず950℃超では粗粒化により
靭性の低下をまねくためである。
２次熱処理時の焼戻し温度は１次熱処理時の焼
戻し温度より低いことを原則とするが、100〜650
℃とする理由は、100℃未満では焼入時の残留応
力の解放が不十分であり650℃超では１次熱処理
でえられた内面部の強度低下を招くためである。
２次熱処理において内面を冷却しながら外表面
を高速加熱する理由は外表面加熱時の内面への熱
影響を防止するためである。
高速加熱とは、800〜950℃の範囲の目標温度ま
で10分〜１時間で達する程度の速度である。
本発明の好ましい態様に従うと、２次熱処理に
於けるスリーブの加熱は高周波誘導加熱で行い、
スリーブの内面には水冷又はミスト冷却する。
１次熱処理時の焼戻し温度はAc3点以下を原則
とするが、500〜700℃とする理由は、500℃未満
では十分な焼戻し効果が得られず700℃超では所
定の強度が得られないためである。２次熱処理
は、スリーブ内面を冷却する点以外は従来方法と
相違しない。本発明の場合、スリーブ内面に冷却
によつて、スリーブ内部の強度、靭性が保持され
る。
以下、本発明を実施例によつて説明する。これ
らの実施例は本発明の方法の例示であつて、本発
明の技術的範囲を何等制限しないのは勿論であ
る。
実施例
第１表に示す組成を有する外径1448mm、内径
1000mm、長さ2007mmのスリーブを本発明方法及び
従来方法で熱処理した。
The present invention relates to a heat treatment method for a sleeve for a variable crown roll, and particularly to a two-step heat treatment method for making the outer surface highly hard and the inner surface high in toughness and strength. A variable crown roll is one in which the radial dimension of the roll sleeve surface can be changed by applying hydraulic pressure from the inner surface of the roll sleeve. It's a roll like this. This type of roll has the inherent properties of a hard surface, wear resistance, and spalling resistance, as well as being able to bend sufficiently in response to the pressure oil applied to the sleeve and maintaining sufficient strength against the pressure oil force. High strength and toughness are required. Traditionally, sleeves of sleeve-type rolling rolls are made of carbon.
0.45~1.00%, silicon 0.10~1.00%, manganese 0.15~
1.00%, chromium 1.50~8.00%, molybdenum 0.05~
Made from steel with a composition of 2.0%, the balance being iron and unavoidable impurities, and after undergoing conventional primary heat treatment,
The following secondary heat treatment was performed. In other words, both ends of the sleeve are covered with steel plates,
After sealing the gap with an amorphous refractory material, etc., it is rapidly heated while rotating in a direct-fired heating furnace, and after the outer surface temperature reaches a range of 800 to 950°C, it is rapidly cooled. Next, after heating the sleeve to a temperature in the range of 100 to 650°C,
It is air cooled. However, in the conventional technology, although sufficient hardness can be obtained on the sleeve surface, the internal mechanical properties including toughness are not sufficient, and the strength characteristics against pressure oil are not sufficient for use as a sleeve for variable crown rolls. It was hot. (Problems to be Solved by the Invention) The present invention aims to solve the above-mentioned problems of the prior art.More specifically, it is an object of the present invention to provide a variable crown roll having sufficiently high surface hardness, internal strength and toughness. The purpose is to provide sleeves. (Means for Solving the Problems) The present invention provides a heat treatment method for a sleeve for a variable crown roll manufactured from the above-described material, in which the sleeve is heated to a temperature in the range of 800 to 950°C as a primary heat treatment. After holding, oil quenching and then 500
After heating and holding in the range of ~700℃, cooling with oil, as a secondary heat treatment, while cooling the inner surface of the sleeve, the outer surface is rapidly heated and held in the range of 800 to 950℃, then rapidly cooled, and then the sleeve is heated to a temperature of 100 to 650℃. The above-mentioned heat treatment method is characterized in that it consists of heating to a temperature range of 0.degree. C. and then air cooling. (Function) The reason why the material of the sleeve is limited as described above in the present invention will be described below. Carbon is a basic additive element that increases hardenability and also brings about precipitation hardening due to molybdenum and chromium carbides. However, if the carbon content is too large, the pro-eutectoid carbides will become coarse, leading to a decrease in toughness, so the content should be 1.00% or less, and if it is too low, sufficient tempering hardness cannot be obtained, so the content should be 0.45% or more. Silicon is contained as a deoxidizing agent in steelmaking and has a content of 0.10%.
If it is less than 1.00%, a sufficient deoxidizing effect cannot be obtained, and if it exceeds 1.00%, it is excessive as a deoxidizing agent and is not practical. Manganese improves hardenability and prevents ferrite formation, and also forms MnS-based inclusions with sulfur.
It is an essential element to impart machinability.
If it is too high, the machinability will decrease, so it should be 1.00% or less, and if it is too low, the above effect will not be obtained, so 0.15
% or more. Chromium improves hardenability and also causes carbide precipitation during tempering to adjust hardness during precipitation hardening.
If it is too high, it will lead to the formation of ferrite, so it should be 8.0% or less, and if it is too low, the above effect will not be obtained, so it should be 1.5%.
% or more. Molybdenum is an element that precipitates carbides during tempering and brings about precipitation hardening. If the content is too high, machinability and toughness will deteriorate, so the content should be 2.00% or less. If the content is too low, the above effects cannot be obtained, so the content should be 0.050% or more. The reason why the heat treatment is performed in two steps is as follows. The primary heat treatment aims at refining the entire material and imparts a predetermined strength and toughness to the material. In the secondary heat treatment, the vicinity of the surface of the material is heated again to an austenitic state, then cooled with oil, and tempered at a temperature lower than the tempering temperature during the primary heat treatment.
This imparts high hardness to the surface. Quenching heating temperature during primary and secondary heat treatment to 800
The reason why the temperature is set at ~950°C is that if the temperature is less than 800°C, sufficient austenitization cannot be obtained, and if it exceeds 950°C, the grains become coarser, leading to a decrease in toughness. In principle, the tempering temperature during secondary heat treatment is lower than the tempering temperature during primary heat treatment;
The reason for setting the temperature is that if it is less than 100°C, the release of residual stress during quenching is insufficient, and if it exceeds 650°C, the strength of the inner surface obtained by the primary heat treatment will decrease. The reason for rapidly heating the outer surface while cooling the inner surface in the secondary heat treatment is to prevent thermal effects on the inner surface during heating of the outer surface. Rapid heating is a rate at which the target temperature in the range of 800 to 950°C is reached in 10 minutes to 1 hour. According to a preferred embodiment of the present invention, the sleeve is heated in the secondary heat treatment by high frequency induction heating,
The inner surface of the sleeve is cooled with water or mist. In principle, the tempering temperature during the primary heat treatment is set to Ac 3 points or less, but the reason for setting it to 500-700℃ is that a sufficient tempering effect cannot be obtained below 500℃, and the required strength cannot be obtained above 700℃. It's for a reason. The secondary heat treatment is the same as the conventional method except that the inner surface of the sleeve is cooled. In the case of the present invention, the inner strength and toughness of the sleeve are maintained by cooling the inner surface of the sleeve. Hereinafter, the present invention will be explained with reference to Examples. It goes without saying that these Examples are illustrative of the method of the present invention and do not limit the technical scope of the present invention in any way. Example: Outer diameter 1448 mm, inner diameter having the composition shown in Table 1
A sleeve with a length of 1000 mm and a length of 2007 mm was heat treated using the method of the present invention and the conventional method.
【表】
本発明方法では、第１図に図解するように、
850℃で３時間加熱保持後、油焼入れし、次いで
650℃で20時間加熱保持し、油冷する１次熱処理
と、内面に１ｍ／秒のミストを噴射しながら、外
表面を900℃に高周波加熱し、２時間保持後、油
冷し、次いで500℃にスリーブ全体を加熱し、10
時間保持後、空冷する２次熱処理からなる。第２
図参照。
従来方法では、１次熱処理850℃に３時間加熱
保持後、油焼入れし、次いで750℃で20時間保持
後、空冷することによつて行い、２次熱処理は内
面を冷却しない点以外は本発明方法と同様であ
る。
熱処理後のスリーブの機械的特性は第２表のと
おりであつた。[Table] In the method of the present invention, as illustrated in FIG.
After heating and holding at 850℃ for 3 hours, oil quenching and then
The first heat treatment involves heating and holding at 650℃ for 20 hours and cooling with oil.The outer surface is high-frequency heated to 900℃ while spraying a mist of 1m/sec on the inner surface.After holding for 2 hours, oil-cooling, then 500℃. Heat the entire sleeve to 10 °C.
It consists of a secondary heat treatment of air cooling after holding for a certain period of time. Second
See diagram. In the conventional method, the first heat treatment is carried out by heating and holding at 850°C for 3 hours, followed by oil quenching, then holding at 750°C for 20 hours, and air cooling. The method is similar. The mechanical properties of the sleeve after heat treatment were as shown in Table 2.
【表】
以上の如く、本発明の熱処理方法で処理された
スリーブは、従来方法によるものと比較して、表
面硬度及び引張強度ともに優れている。[Table] As described above, the sleeves treated by the heat treatment method of the present invention are superior in both surface hardness and tensile strength compared to sleeves treated by the conventional method.
第１図は、本発明の実施例における第１次熱処
理操作を説明する線図；および第２図は、同じく
第２次熱処理操作を説明する線図である。
FIG. 1 is a diagram illustrating a first heat treatment operation in an embodiment of the present invention; and FIG. 2 is a diagram illustrating a second heat treatment operation.
Claims (1)
1.00％、マンガン0.15〜1.00％、クロム1.50〜8.00
％、モリブデン0.05〜2.0％、残部鉄および不可
避不純物からなる鋼組成を有し、１次熱処理およ
び２次熱処理を施工する可変クラウンロール用ス
リーブの熱処理方法に於いて、１次熱処理として
該スリーブを800〜950℃の範囲に加熱保持した
後、油焼入れし、次いで500〜700℃の範囲に加熱
保持した後に油冷し、２次熱処理として、該スリ
ーブ内面を冷却しながら外表面を800〜950℃の範
囲に高速加熱保持後に急冷し、次いで該スリーブ
を100〜650℃の範囲に加熱後、空冷することを特
徴とする可変クラウンロール用スリーブの熱処理
方法。1% by weight, carbon 0.45~1.00%, silicon 0.10~
1.00%, manganese 0.15-1.00%, chromium 1.50-8.00
%, molybdenum 0.05 to 2.0%, balance iron and unavoidable impurities. After heating and holding in the range of 800 to 950℃, oil quenching is carried out. Next, after heating and holding in the range of 500 to 700℃, oil cooling is performed. As a secondary heat treatment, the outer surface is heated to 800 to 950℃ while cooling the inner surface of the sleeve. 1. A method for heat treating a sleeve for a variable crown roll, comprising: heating and holding the sleeve at a high speed in a temperature range of 100 to 650 °C, and then cooling the sleeve in air.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2789183A JPS59153835A (en) | 1983-02-22 | 1983-02-22 | Heat treatment of sleeve for variable crown roll |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2789183A JPS59153835A (en) | 1983-02-22 | 1983-02-22 | Heat treatment of sleeve for variable crown roll |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59153835A JPS59153835A (en) | 1984-09-01 |
| JPS6348924B2 true JPS6348924B2 (en) | 1988-10-03 |
Family
ID=12233511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2789183A Granted JPS59153835A (en) | 1983-02-22 | 1983-02-22 | Heat treatment of sleeve for variable crown roll |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59153835A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107760840A (en) * | 2016-08-22 | 2018-03-06 | 中国石油化工股份有限公司 | A kind of heat treatment method of expansion of metal sleeve |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5332846A (en) * | 1976-09-08 | 1978-03-28 | Hitachi Ltd | Method of cooling weld zone of steel tubes and apparatus therefor |
| JPS5643300A (en) * | 1979-09-14 | 1981-04-21 | Parajiino Gaetano | Novel manufacture of pregnane 22bromoo6betaa fluoroo33ketoodelta1*44steroid compound |
| JPS5835577B2 (en) * | 1979-10-30 | 1983-08-03 | 川崎製鉄株式会社 | Method for manufacturing rolls for hot leveler |
-
1983
- 1983-02-22 JP JP2789183A patent/JPS59153835A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107760840A (en) * | 2016-08-22 | 2018-03-06 | 中国石油化工股份有限公司 | A kind of heat treatment method of expansion of metal sleeve |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59153835A (en) | 1984-09-01 |
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