JPH07197179A - Heat resistant alloy for hearth member in steel material heating furnace - Google Patents
Heat resistant alloy for hearth member in steel material heating furnaceInfo
- Publication number
- JPH07197179A JPH07197179A JP71594A JP71594A JPH07197179A JP H07197179 A JPH07197179 A JP H07197179A JP 71594 A JP71594 A JP 71594A JP 71594 A JP71594 A JP 71594A JP H07197179 A JPH07197179 A JP H07197179A
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- Prior art keywords
- alloy
- heat
- steel material
- heating furnace
- resistant alloy
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、加熱炉内の被加熱鋼材
を担持するスキッドボタン等の炉床部材の構成材料とし
て使用される高温特性にすぐれた耐熱合金に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant alloy having excellent high-temperature characteristics which is used as a constituent material of a hearth member such as a skid button for supporting a steel material to be heated in a heating furnace.
【０００２】[0002]
【従来の技術】スラブやビレット等の鋼材は、熱間圧延
や熱間鍛造等の熱間塑性加工に際して、加熱炉に装入さ
れ所定の加熱処理を受ける。加熱炉に装入された鋼材の
鋼材搬送装置、例えばウオーキングビームコンベアの固
定ビームおよび可動ビームは、炉長方向に配置されたス
キッドパイプ（鋼管）の周面頂部に、鋼材支持面部材で
あるスキッドボタンを管軸方向に一定の間隔を置いて固
定した構造を有し、被加熱鋼材は、スキッドボタンの頂
面に担持されて炉内を搬送される。上記スキッドボタン
は、炉内の高温酸化雰囲気（温度約１２００℃以上）に
対する耐酸化性、および重量物である鋼材の負荷に抗し
得る圧縮変形抵抗性等の高温強度が要求される。従来よ
りその耐熱材料として、Ｃｏ含有Ｎｉ−Ｃｒ系合金鋼
（例えば50Ｃｏ−20Ｎｉ−30Ｃｒ−Ｆｅ）等に代表され
る高合金が使用されてきた。2. Description of the Related Art Steel materials such as slabs and billets are loaded into a heating furnace and subjected to a predetermined heat treatment during hot plastic working such as hot rolling and hot forging. The steel material conveying device for the steel material charged into the heating furnace, for example, the fixed beam and the movable beam of the walking beam conveyor, is a skid pipe (steel pipe) arranged in the furnace longitudinal direction, and a skid that is a steel material supporting surface member at the top of the peripheral surface. It has a structure in which the buttons are fixed at regular intervals in the pipe axis direction, and the steel material to be heated is carried on the top surface of the skid button and conveyed in the furnace. The skid button is required to have high-temperature strength such as oxidation resistance against a high-temperature oxidizing atmosphere (temperature of about 1200 ° C. or higher) in the furnace, and compression deformation resistance capable of withstanding the load of a heavy steel material. Conventionally, a high alloy represented by a Co-containing Ni-Cr alloy steel (for example, 50Co-20Ni-30Cr-Fe) has been used as the heat resistant material.
【０００３】加熱炉操業は生産性向上・鋼材の圧延品質
向上等の要請から、操炉温度が高められ、1250℃を越
え、1300℃ないしそれ以上の高温操業が一般化しつつあ
る。従来の耐熱合金では、このような高温環境おける耐
酸化性や高温強度が不足する。スキッドボタンに対する
高温酸化雰囲気の影響は、スキッドパイプ内を流通する
冷却水による冷却作用を強めることにより、ある程度緩
和することはできるが、スキッドボタンの冷却を強める
ことは、被加熱鋼材の加熱ムラ（スキッドボタンと接触
する部分の温度低下、いわゆるスキッドマーク）の発生
を助長し、後工程での品質（圧延品質等）を損なう原因
となり、また炉内熱量が冷却水に奪われることによる熱
経済性の著しい低下を余儀なくされる。特開平3-162545
号公報には、このような高温操業に対処するための改良
された高温特性を有する炉床部材用耐熱合金として、60
％以上のＣｒを含有し、結晶粒径が50μｍ以上であるＣ
ｒ−Ｆｅ合金が開示されている。[0003] In the heating furnace operation, the operation temperature is raised to exceed the temperature of 1250 ° C and the operation at a high temperature of 1300 ° C or higher is becoming popular because of the demands for improving productivity and rolling quality of steel. The conventional heat-resistant alloy lacks oxidation resistance and high-temperature strength in such a high-temperature environment. The influence of the high-temperature oxidizing atmosphere on the skid button can be mitigated to some extent by strengthening the cooling action of the cooling water flowing in the skid pipe, but strengthening the cooling of the skid button means heating unevenness of the heated steel ( The temperature drop at the part that comes into contact with the skid button, so-called skid marks, is promoted, which causes the quality (rolling quality, etc.) in the post-process to be impaired, and the heat economy in the furnace due to the heat being taken away by the cooling water. Forced to drop significantly. JP-A-3-162545
In the gazette, as a heat-resistant alloy for hearth members having improved high-temperature characteristics for coping with such high-temperature operation, 60
% Cr or more and has a crystal grain size of 50 μm or more
An r-Fe alloy is disclosed.
【０００４】[0004]
【発明が解決しようとする課題】上記公報に開示された
Ｃｒ−Ｆｅ合金は、その化学組成と結晶組織に基づく効
果として、そこに記載されているように従来の耐熱合金
を大きく凌ぐ改良された高温特性を有し、殊に圧縮変形
抵抗性，クリープ破断抵抗性，および耐酸化性等に優れ
ている。本発明は、このＣｒ−Ｆｅ系合金の高温特性を
更に高めることを目的としてなされたものである。The Cr-Fe alloy disclosed in the above publication has been improved as a result based on its chemical composition and crystal structure, as compared with the conventional heat-resistant alloy. It has high-temperature characteristics and is particularly excellent in compression deformation resistance, creep rupture resistance, and oxidation resistance. The present invention has been made for the purpose of further improving the high temperature characteristics of this Cr-Fe alloy.
【０００５】[0005]
【課題を解決するための手段】本発明の耐熱合金は、Ｃ
ｒ：６０〜９５％、およびＢ：０．１〜２％を含有し、
Ｃ：０．８％以下の混在が許容され、残部は実質的にＦ
ｅからなる化学組成を有し、結晶粒径が５０μｍ以上で
あることを特徴としている。The heat-resistant alloy of the present invention comprises C
r: 60 to 95%, and B: 0.1 to 2%,
C: Mixing of 0.8% or less is allowed, and the balance is substantially F
It is characterized by having a chemical composition of e and having a crystal grain size of 50 μm or more.
【０００６】[0006]
【作用】Ｃｒ６０〜９５％を含有するＣｒ−Ｆｅ合金
に、０．１〜２％のＢを添加してなる本発明の耐熱合金
は、Ｂ添加の効果として、高温酸化雰囲気においてＣｒ
−Ｆｅ合金と同等の高度の耐酸化性を維持しながら、よ
り高度の圧縮変形抵抗性やクリープ破断強度を発現す
る。The heat-resistant alloy of the present invention, which is obtained by adding 0.1 to 2% of B to a Cr-Fe alloy containing 60 to 95% of Cr, has the effect of adding B as a result of adding Cr in a high temperature oxidizing atmosphere.
-Higher compression deformation resistance and creep rupture strength are expressed while maintaining the same high degree of oxidation resistance as the Fe alloy.
【０００７】本発明合金のＣｒ量を６０％以上としたの
は、１３００℃ないしそれ以上の高温酸化雰囲気炉にお
ける高温強度および酸化抵抗性を確保するためであり、
その上限を９５％としたのは、Ｃｒの増量による合金の
融点の上昇に伴い、鋳造合金として製造する場合の溶解
・鋳造性、および焼結合金として製造する場合の焼結性
が悪くなり、このことは合金の品質の低下の原因となる
からである。The Cr content of the alloy of the present invention is set to 60% or more in order to secure high temperature strength and oxidation resistance in a high temperature oxidizing atmosphere furnace at 1300 ° C. or higher.
The upper limit is set to 95%, as the melting point of the alloy increases due to the increase in Cr, the melting / castability in the case of manufacturing as a cast alloy and the sinterability in the case of manufacturing as a sintered alloy deteriorate, This is because it causes deterioration of the quality of the alloy.
【０００８】Ｂは、高温域における圧縮変形抵抗性を高
め、かつクリープ破断強度の向上に著効を示す。その効
果は０．１％以上の添加により得られる。添加増量によ
り効果を増すが、過度の添加は合金の耐酸化性の低下を
招く。このため、２％を上限とした。[0008] B is highly effective in improving the resistance to compressive deformation in the high temperature range and improving the creep rupture strength. The effect is obtained by adding 0.1% or more. The effect is enhanced by increasing the amount of addition, but excessive addition causes a decrease in the oxidation resistance of the alloy. Therefore, the upper limit is 2%.
【０００９】Ｃは必須の元素ではないが、０．８％以下
のＣの混在によって本発明の趣旨が損なわれることはな
く、むしろその混在は合金融点の適度の低下，合金溶湯
の流動性の向上等により溶解精錬の困難を緩和し、また
焼結合金として製造する場合の焼結性の向上に奏効す
る。よって、０．８％以下のＣの混在を許容することと
した。C is not an essential element, but the inclusion of 0.8% or less of C does not impair the gist of the present invention. Rather, the inclusion of C is a moderate decrease in the melting point of the alloy and the fluidity of the molten alloy. It is effective in alleviating the difficulty of melting and refining by improving the alloy and improving the sinterability in the case of producing a sintered alloy. Therefore, it is decided to allow the mixture of C of 0.8% or less.
【００１０】本発明合金の高温強度は結晶粒径に大きく
依存する。結晶粒径を５０μｍ以上としたのは、その粗
大粒結晶組織とすることにより、Ｃｒ- Ｂ- Ｆｅ組成を
有する本発明合金の改良された高温強度を充分に発現す
ることが可能となるからである。The high temperature strength of the alloy of the present invention largely depends on the crystal grain size. The crystal grain size is set to 50 μm or more because its coarse grain structure makes it possible to sufficiently exhibit the improved high-temperature strength of the alloy of the present invention having the Cr—B—Fe composition. is there.
【００１１】本発明の耐熱合金は、溶解・鋳造プロセス
による鋳造合金、または粉末冶金の手法（例えば熱間静
水圧加圧焼結法）による焼結合金として製造される。鋳
造および焼結のいずれの製造プロセスによる場合にも、
これを上記の粗粒組織とすることに困難はなく、鋳造合
金として製造する場合には、砂型鋳型を使用して、比較
的緩慢な冷却凝固を行わせて粒成長を促進させることに
より、また冷却速度の高い金型鋳型を使用する鋳造で
は、鋳造工程の後、加熱処理（例えば、１３００〜１６
００℃に５〜２０Ｈｒ保持）を施して結晶粒を成長粗大
化させることにより所定の粗粒組織を形成することがで
きる。また焼結手法による場合は、焼結原料粉末とし
て、粗粒の粉末( 平均粒径約２００μｍ以上）を使用
し、加熱・加圧下（温度：１０００〜１５００℃，加圧
力：１０００〜２０００Kgf ／cm2 、処理時間：約２〜
５Ｈｒ）の焼結処理を行うか、または焼結処理の後、焼
結合金塊に粗粒化のための前記と同様の加熱処理を施す
ようにすればよい。The heat-resistant alloy of the present invention is manufactured as a casting alloy by a melting / casting process or a sintered alloy by a powder metallurgy method (for example, hot isostatic pressing method). Whether by casting or sintering manufacturing process,
It is not difficult to make it the above-mentioned coarse grain structure, and when it is produced as a casting alloy, by using a sand mold, by relatively slow cooling and solidifying to promote grain growth, In casting using a mold having a high cooling rate, heat treatment (for example, 1300 to 16) is performed after the casting step.
A predetermined coarse grain structure can be formed by subjecting the crystal grain to growth coarsening by applying 5 to 20 hours at 00 ° C.). In the case of the sintering method, coarse-grained powder (average particle size of about 200 μm or more) is used as the sintering raw material powder, and under heating / pressurization (temperature: 1000 to 1500 ° C., pressing force: 1000 to 2000 Kgf / cm). 2 , processing time: about 2
The sintering treatment may be performed for 5 hours or after the sintering treatment, the sintered alloy ingot may be subjected to the same heat treatment as described above for coarsening.
【００１２】なお、本発明の耐熱合金を適用して形成さ
れる炉床部材は必ずしもその全体を本発明の耐熱合金で
形成する必要はない。例えばを図１に示すように、スキ
ッドパイプＰの周面頂部に、鋼材支持面部材であるスキ
ッドボタン１０を固定（溶接等）して構成されるウオー
キングビームコンベアの固定・可動ビームにおけるスキ
ッドボタン１０（柱状ないし錐台形状部材である）に本
発明の耐熱合金を適用する場合には、被加熱鋼材Ｓが接
触する頂部側に本発明の耐熱合金を適用する一方、底部
側（スキッドパイプＰ内の冷却水による強い冷却作用が
加わる部分）は従来の耐熱合金鋼で形成し、その頂部側
のブロック１１と底部側のブロック１２とを上下に重合
わせ、重ね合せ面を接合（例えば拡散接合）した積層構
造を有する複合体とすることも可能である。The hearth member formed by applying the heat-resistant alloy of the present invention does not necessarily have to be entirely formed of the heat-resistant alloy of the present invention. For example, as shown in FIG. 1, a skid button 10 in a fixed / movable beam of a walking beam conveyor configured by fixing (welding, etc.) a skid button 10 which is a steel supporting surface member to the top of the peripheral surface of a skid pipe P. When the heat-resistant alloy of the present invention is applied to (a columnar or frustum-shaped member), the heat-resistant alloy of the present invention is applied to the top side with which the steel S to be heated contacts, while the bottom side (inside the skid pipe P) Of the conventional heat-resistant alloy steel, the block 11 on the top side and the block 12 on the bottom side are vertically overlapped, and the overlapping surfaces are joined (for example, diffusion joining). It is also possible to make a composite having the above laminated structure.
【００１３】[0013]
【実施例】高周波溶解炉（Ａｒ雰囲気）で溶製した合金
溶湯を砂型（ＣＯ2 珪砂鋳型）による鋳造に付し、供試
合金ブロック（φ70×90 l, mm）を得た。各供試合金ブ
ロックから試験片を切出し、下記の試験を行った。[Examples] A molten alloy melt produced in a high-frequency melting furnace (Ar atmosphere) was cast by a sand mold (CO 2 silica sand mold) to obtain a matchmaking block (φ70 × 90 l, mm). Test pieces were cut out from each match money block and the following tests were conducted.
【００１４】（１）高温圧縮試験 円柱状試験片（φ30×50 l, mm）を固定台上に直立載置
して1350℃に加熱保持し、試験片の天面に垂直荷重0.5
Kgf/mm2 を加える。試験時間（Ｔ）：50Ｈr 。試験片の
試験前の高さ寸法（Ｌｏ）と試験後の高さ寸法（Ｌ）か
ら、圧縮変形速度Ｄ％／Ｈr 〔圧縮変形量Ｄ％＝（Ｌｏ
−Ｌ）／Ｌｏ・Ｔ ×100 （％）〕を求める。(1) High-temperature compression test A cylindrical test piece (φ30 × 50 l, mm) was placed upright on a fixed table, heated and held at 1350 ° C., and a vertical load of 0.5 was applied to the top surface of the test piece.
Add Kgf / mm 2 . Test time (T): 50 hr. From the height dimension (Lo) of the test piece before the test and the height dimension (L) after the test, the compression deformation rate D% / Hr [compression deformation amount D% = (Lo
−L) / Lo · T × 100 (%)].
【００１５】（２）高温クリープ破断試験 試験片（φ６×80 l，mm）を1250℃に加熱保持して1.0
Kgf/mm2 の引張応力を加え、破断に到るまでの時間（Ｈ
ｒ）を測定。(2) High temperature creep rupture test A test piece (φ6 × 80 l, mm) was heated to 1250 ° C. and held at 1.0
Time required to reach rupture by applying tensile stress of Kgf / mm 2 (H
r) is measured.
【００１６】（３）高温酸化試験 試験片（φ８×50 l, mm）を加熱炉（大気雰囲気）中、
1350℃に100 時間加熱保持する。試験後、試験片表面の
酸化スケールを除去し、試験片の重量変化から酸化減量
（ｇ／m2hr）を求める。(3) High temperature oxidation test A test piece (φ8 × 50 l, mm) was placed in a heating furnace (atmosphere).
Heat at 1350 ° C for 100 hours. After the test, the oxidized scale on the surface of the test piece is removed, and the weight loss of oxidation (g / m 2 hr) is determined from the weight change of the test piece.
【００１７】表１に供試合金ブロックの化学組成（ｗｔ
％）と上記試験結果を示す。表中、No.1〜４は発明例、
No.11,No.12 は比較例である。比較例のうち、No.11 は
Ｂの添加が省略されたＣｒ−Ｆｅ合金の例であり、No.1
2 は従来の代表的なスキッドボタン材料である高Ｃｏ含
有Ｎｉ−Ｃｒ系耐熱合金鋼（０．３Ｃ−２７．１Ｃｒ−
１９．８Ｎｉ−４０．４Ｃｏ−Ｆｅ）である。Table 1 shows the chemical composition (wt) of the match money block.
%) And the above test results are shown. In the table, Nos. 1 to 4 are invention examples,
No. 11 and No. 12 are comparative examples. Among the comparative examples, No. 11 is an example of the Cr-Fe alloy in which the addition of B was omitted, and No. 1
2 is a high-Co Ni-Cr heat-resistant alloy steel (0.3C-27.1Cr-), which is a typical conventional skid button material.
19.8Ni-40.4Co-Fe).
【００１８】[0018]
【表１】 [Table 1]
【００１９】表１に示したとおり、発明例No. １〜４
は、従来のスキッドボタン材料である高ＣｏのＣｒ−Ｎ
ｉ系合金鋼（No.11 ）に比し、格段にすぐれた高温圧縮
変形抵抗性、クリープ破断強度、および耐酸化性等を有
し、かつその高温変形強度は、Ｂを含まないＣｒ−Ｆｅ
合金であるNo.12 を顕著に凌ぎ、また高温耐酸化性もN
o.12 のそれと同等ないしそれ以上の水準を保持してい
る。As shown in Table 1, Invention Examples Nos. 1 to 4
Is a high Co Cr-N which is a conventional skid button material.
Cr-Fe, which has outstandingly superior high-temperature compression deformation resistance, creep rupture strength, oxidation resistance, etc. compared to i-based alloy steel (No. 11), and whose high-temperature deformation strength does not include B
Remarkably surpasses alloy No. 12 and has high-temperature oxidation resistance N
It holds a level equal to or higher than that of o.12.
【００２０】[0020]
【発明の効果】本発明の耐熱合金は、従来の炉床部材用
耐熱合金では得られない卓抜した高温圧縮強度、耐酸化
性、ラプチャー強度を具備し、近時の操炉条件の高温度
化に対する炉床部材の安定化、耐久性の向上・メンテナ
ンスの軽減に奏効し、操炉効率の向上に寄与する。ま
た、そのすぐれた高温特性により、従来の耐熱合金から
なる炉床部材に比し、冷却水による強制冷却を緩和する
ことができ、被加熱鋼材のスキッドマークの軽減・均一
加熱による鋼材圧延品質の向上等の効果、および冷却水
による炉内の熱損失量の減少・省エネルギ効果等を得る
ことができる。EFFECTS OF THE INVENTION The heat-resistant alloy of the present invention has outstanding high-temperature compressive strength, oxidation resistance, and rupture strength that cannot be obtained by the conventional heat-resistant alloys for hearth members, and has raised the operating temperature under recent conditions. It is effective in stabilizing the hearth material, improving durability and reducing maintenance, and contributes to improvement of furnace operation efficiency. In addition, due to its excellent high-temperature characteristics, forced cooling by cooling water can be mitigated compared to conventional hearth members made of heat-resistant alloys, the skid marks of heated steel can be reduced, and the quality of steel rolling can be improved by uniform heating. It is possible to obtain effects such as improvement, reduction of heat loss in the furnace due to cooling water, and energy saving effects.
【図１】鋼材加熱炉内のスキッドビームを示す断面図で
ある。FIG. 1 is a cross-sectional view showing a skid beam in a steel material heating furnace.
【符号の説明】 １０：スキッドボタン、Ｐ：スキッドパイプ、Ｓ：被加
熱鋼材。[Explanation of Codes] 10: skid button, P: skid pipe, S: steel to be heated.
Claims (2)
〜２％を含有し、Ｃ：０．８％以下の混在が許容され、
残部は実質的にＦｅからなる化学組成を有し、結晶粒径
５０μｍ以上であることを特徴とする鋼材加熱炉の炉床
部材用耐熱合金。1. Cr: 60 to 95%, and B: 0.1
~ 2%, C: 0.8% or less of the mixture is allowed,
The balance has a chemical composition substantially consisting of Fe and has a crystal grain size of 50 μm or more, which is a heat-resistant alloy for hearth members of a steel heating furnace.
アのスキッドパイブに取り付けられる鋼材支持面部材で
あることを特徴とする請求項１に記載の鋼材加熱炉の炉
床部材用耐熱合金。2. The heat-resistant alloy for a hearth member of a steel heating furnace according to claim 1, wherein the hearth member is a steel material supporting surface member attached to a skid pipe of a walking beam conveyor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP71594A JPH07197179A (en) | 1994-01-10 | 1994-01-10 | Heat resistant alloy for hearth member in steel material heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP71594A JPH07197179A (en) | 1994-01-10 | 1994-01-10 | Heat resistant alloy for hearth member in steel material heating furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07197179A true JPH07197179A (en) | 1995-08-01 |
Family
ID=11481464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP71594A Pending JPH07197179A (en) | 1994-01-10 | 1994-01-10 | Heat resistant alloy for hearth member in steel material heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07197179A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014189842A (en) * | 2013-03-27 | 2014-10-06 | Kubota Corp | Skid button |
-
1994
- 1994-01-10 JP JP71594A patent/JPH07197179A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014189842A (en) * | 2013-03-27 | 2014-10-06 | Kubota Corp | Skid button |
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