JPH0124859B2

JPH0124859B2 -

Info

Publication number: JPH0124859B2
Application number: JP25629785A
Authority: JP
Inventors: Motohisa Myato; Takeo Yuji; Riichi Tsuno
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1985-11-15
Filing date: 1985-11-15
Publication date: 1989-05-15
Also published as: JPS62116757A

Description

[Detailed description of the invention]

［産業上の利用分野］本発明は鋼電磁撹拌連続鋳造用管型鋳型材料の
製造方法に関する。さらに詳しくは、電磁撹拌装
置を設置した鋼等の連続鋳造に用い、鋳型材料に
適した物理的性質および機械的性質を備えた連続
鋳造用管型鋳型材料の製造方法に関する。［発明の背景］最近、鋼等の連続鋳造法において、電磁撹拌を
行うことが採用されてきている。そのため鋳塊の
品質が改善され、さらには、高級鋼を連続鋳造す
ることもできるようになつてきている。しかし従
来の鋼等の連続鋳造に使用される鋳型材料では、
常温耐力が25Kgｆ／mm²以下、硬度がHv85以下で
あるために、電磁撹拌装置を設置した場合には、
鋳型にとつて鋳造法に比較して、非常に苛酷な条
件となつて、強度および耐摩耗性の面から問題が
ある。この問題を解決しようとして開発された、Cu
−Cr−Zr系合金は、導電率が80％IACSもあり導
電率が高過ぎるため、金型における電磁撹拌のエ
ネルギー源である磁場が吸収されるため電源の大
容量化が必要となる。そのため、操業時に大電力
を要する等、問題が発生した。これらの問題点を回避するために、導電率が低
く、耐熱性および高温強度の優れているCu−Cr
−Zr−Alなどの合金が開発されている。しかし、Cu−Cr−Zr系合金は溶解する上で、
溶湯の酸化が激しいために、大気溶解が極めて困
難であり、真空溶解が必要となり、高価になる欠
点がある。さらに、製造する上で、脱酸銅工程お
よびそれに準じた工程で製造可能であることが前
提となる。また、モールドは大径管（熱間押し出
し寸法189φ×152φmm）であり、熱間押し出し以
後は、強度および硬度を軟質化し、加工性を良く
するために、変速的な加工工程、即ち低加工率の
冷間加工と高温での溶体化処理とのくり返しを行
う。このような熱処ののため２次再結晶粒が粗大
化し、Cu−Cr−Zr系合金では、抽伸割れを生じ
るという問題点がある。［発明の目的］鋳型材の導電率を40〜50％IACSとし、電磁撹
拌装置よりの磁場を鋳型で消費することがなく、
更に、導電率の低下に基く熱伝導率の低下による
鋳型の軟化および変形を無くし、鋼等の高速連続
鋳造を円滑に行うことができ、生産性を向上さ
せ、ヴイツカース硬度が160以上、軟化温度が425
℃以上である銅合金よりなる析出硬化型の鋼電磁
撹拌連続鋳造用鋳型材の製造方法を提供するもの
である。［発明の概要］本発明の要旨は、Ni0.4〜2.0wt％、Si0.1〜
0.4wt％、Zn0.05〜1.0wt％、Mn0.02〜0.1wt％、
さらにMg、Cr、ZrおよびTiのうち１種あるい
は、２種以上を総量で、0.001〜0.1wt％を含有
し、残部Cuおよび不可避不純物からなる銅合金
の鋳塊を熱間押し出しする際に、該鋳塊を加熱す
る時の昇温速度を200℃／時間以上とし、該鋳塊
を熱間押し出し後は、600℃以上から５℃／秒以
上の速度で冷却し、次に、減面率で５〜30％の
冷間加工工程と、600℃〜800℃の温度での焼鈍
工程と、５℃／秒以上の速度での冷却工程の３
工程を２回以上繰り返し、次いで、減面率で５〜
30％の冷間加工を行なつた後時効処理を行なうこ
とを特徴とする鋼電磁撹拌連続鋳造用管型鋳型材
の製造方法に存在する。本発明による電磁撹拌連続鋳造用管型鋳型材の
製造方法についての詳細を説明する。先ず、本発明による鋼電磁撹拌連続鋳造用管型
鋳型材における含有成分および、成分割合につい
て説明する。 Niは強度に寄与する元素であり、含有量が
0.4wt％未満ではSiが0.1〜0.4wt％の範囲に含有
されていても強度向上は殆んど期待することがで
きない。また2.0wt％を越えて含有されると導電
率が低下し、さらに、強度向上の効果が小さくな
る。よつてNi含有量は0.4〜2.0wt％とする。 SiはNiとともに強度に寄与する元素であり、
含有量が0.1wt％未満ではNiが0.4〜2.0wt％含有
されていても、高い導電率および強度の向上は期
待できない。また、Siが0.4wt％を越えて含有さ
れると、導電率が低下するとともに、熱間押し出
し加工性、更には中間焼鈍後の冷間加工性を悪化
する。よつてSi含有量は0.1〜0.4wt％とする。 Znはクロームメツキおよびニツケルメツキの
耐剥離性を向上させるのに必須の元素であり、含
有量が0.05wt％未満では、この効果が少ない。ま
た1.0wt％を越えて含有されるとメツキの耐剥離
性が低下する。よつてZn含有量は、0.05〜1.0wt％とする。 Mnは熱間押し出し加工性を向上させる元素で
あり、含有量が0.02wt％未満では、この効果は少
なく、また0.1wt％を越えて含有されると、導電
率が低下する。よつてMn含有量は0.02〜0.1wt％とする。前述の範囲のNiとSiとを含有する合金を熱間
押し出しする場合には、Mgを添加して、粒界に
フリーな状態で存在するＳをMgSとして固定す
るか、Cr、Ti、あるいはZrを添加するかして粒
界を強化する必要がある。 Mgは原料、炉材および溶解時の雰囲気中に含
有されているＳおよびＳ化合物から必然的に混入
してくるＳを安定化する元素であり、Mgとの硫
黄化合物を形成させてＳを銅合金中に固定する。
またMgは粒界を強化して熱間加工性を向上させ
るために必要であり、含有量が0.001wt％未満で
は脱硫効果は少なく、熱間押し出しにおいて加熱
中あるいは熱間押し出し中に粒界割れを生じやす
くなる。また0.1wt％を越えて含有されると、Cu
とMgCu₂の共晶物（722℃）が生じ、この化合物
は低融点であり、750℃以上での熱間加工性を劣
化させ、さらに、溶湯が酸化して湯流れ性を著し
く低下させ、鋳塊も不健全となる。 Cr、TiおよびZrは、結晶粒の微細化と高温強
度の向上および高温伸びを改善する元素であり、
特に熱間押し出し時の割れ防止には必要である。また、Mgが含まれていない場合では、Cr、Ti
およびZrのうちの１種以上が含まれていなけれ
ば、割れを完全に防止することができず、含有量
が0.001wt％未満では上記の効果は少ない。また
0.1wt％を越えて含有されると、熱間押し出し時
の割れはなくなるが、含有量が多くなることによ
つて、高温強度が向上する効果が少なくなり、逆
に溶湯の酸化が激しくなるため、健全な鋳肌の鋳
塊が得られなくなる。よつて、Mg、Cr、ZrおよびTiは、そのうちか
ら選んだ１種あるいは２種以上の総量で0.001wt
％〜0.1wt％とする。次に製造条件について詳述する。上記に説明した成分範囲を持つ銅合金の鋳塊を
熱間押し出しする際に、加熱時の昇温速度を200
℃／時間以上にした理由は、熱間押し出しする際
に、鋳塊の加熱割れを生じさせないためである。
さらに詳しくは、上記に説明した成分範囲を持つ
銅合金は、加熱途中で中高温脆性域を通過する時
に、粒界が脆化し易く、鋳塊の内部応力および熱
応力の相乗作用によつて、加熱割れを起し易くな
り、後工程の製造が不可能となる。よつて、本合金は、加熱時の昇温速度を出来る
だけ速くし、中高温脆性域の温度を速く通過させ
ることが望ましく、その速度を200℃／時間以上
に限定する。更に、熱間押し出し後は、600℃以上の温度か
ら５℃／秒以上の速度で冷却するのは、溶体化処
理にて軟質性を保つためであり、600℃未満の温
度から５℃／秒以上の速度で冷却しても、また
600℃以上の温度から５℃／秒未満で冷却しても、
上記効果が不充分であり、後工程での冷間抽伸で
の加工性が悪くなるためである。次に鋼電磁撹拌連続鋳造用管型鋳型材の製造プ
ロセスは、熱間押し出し、冷間抽伸、溶体化処
理、時効処理である。冷間加工において、苛酷な
低加工率での抽伸および拡管をくり返すために、
硬度および強度が上昇し、加工性が悪くなる。よ
つて少なくとも２回以上の溶体化処理が必要であ
る。次に減面率５％〜30％に冷間加工した後、600
℃〜800℃の温度で焼鈍し、５℃／秒以上の速度
で冷却するのは、溶体化処理により軟化させ、冷
間抽伸および、拡管の加工性を良くするためであ
る。また、焼鈍温度及び冷却温度を限定した理由
は、600℃未満の温度から冷却した場合には、冷
却速度が５℃／秒以上としても、この状態におけ
る材料は、冷却開始前に既にNiとSi化合物の析
出が起つており、充分な溶体化処理が得られず、
その後の冷間加工性を悪化させる。また600℃以
上の温度から冷却しても、冷却速度が５℃／秒未
満の場合は、同様に冷却中にNiとSi化合物の析
出が起り、充分な溶体化処理が得られず、その後
の冷間加工性を悪化させる。 800℃を越える焼鈍では、冷却速度が５℃／秒
未満および５℃／秒以上としても結晶粒度の成長
が著しく、グレイン・グロースを生じるため、冷
間抽伸時に粒界割れを生じる。尚、この中間焼鈍時間は、15分〜２時間とする
ことが望ましい。また、本発明による鋼電磁撹拌連続鋳造用鋳型
材の仕上げ抽伸した後の時効処理は400℃〜550℃
の温度で15分〜５時間焼鈍することにより、硬度
および導電率を向上させることができる。［実施例］第１表に示す含有成分および成分割合の銅合金
をクリプトル炉にて、木炭被覆下に溶解し、ブツ
ク・モールドタイプの鋳鉄金型に鋳込み、厚さ45
mm×幅82mm×長さ200mmの鋳塊を作製した。次に各鋳塊を切断し、面削し、厚さ５mm×幅20
mm×長さ180mmの中高温下での脆化特性評価用の
試験片ならびに、厚さ35mm×幅75mm×長さ200mm
の加工性評価用の試験片を作製した。脆化特性の評価試験は、三点曲げ方法で応力10
Kgｆ／mm²および20Kgｆ／mm²を負荷し、カンタル炉
で800℃／３時間および800℃／4.5時間の昇温速
度で30分間加熱後水中急冷した後、カラーチエツ
クにて割れの有無を調査した。冷間加工性を評価するための試験片は、厚さ35
mmの鋳塊を860℃の温度で加熱し、１パスの圧下
率を約20％とし、４パスで厚さ15mmまで熱間圧延
した後、650℃の温度から水中急冷し、熱間圧延
方向に直角にサンプリングし、厚さ10mm×幅35mm
×長さ200mm、但し中央平行部長さ80mm、幅25mm
の試験片を作製した。これらの試験片を減面率で
10〜30％の引張り加工した後、700℃の温度で30
分焼鈍し、600℃の温度から、水中急冷すること
を２回くり返し、それぞれの引張り加工後の割れ
の発生状況、２回焼鈍後の結晶粒度および機械的
性質を調べた。更に、最終特性の調査のために、減面率10〜30
％の冷間引張材を450℃の温度で５時間の時効処
理を行い、ヴイツカース硬度および導電率の測定
を行つた。第２表および第３表に試験結果を示す。この第２表および第３表から明らかなように、
本発明工程材は、鋼電磁撹拌連続鋳造用管型鋳型
材を製造する上の問題点である加熱割れを無く
し、熱間押し出し時の加工性を改善しており、さ
らに、冷間加工において、必須とする低加工率で
の抽伸および拡管と、高温度の溶体化処理のくり
返しにより生じるグレイン・グロースを抑制し、
容易に現状設備で生産できるようになつた。即ち、本発明工程で製造される本発明合金は、
機械的強度、導電率ならびに耐熱性の優れる特性
を有していることから、鋼電磁撹拌連続鋳造用鋳
型材として使用することによつて、鋳型の寿命を
大幅に向上させることができることを実証してい
る。尚、本発明工程材は、鋼以外に、銅合金の電磁
撹拌連続鋳造用の鋳型材料としても好適である。［発明の効果］以上説明したように、本発明により製造された
鋼電磁撹拌連続鋳造用鋳型材料は、上記の構成を
有しているものであることから、導電率を電磁撹
拌に有効な範囲とすることができ、導電率の低下
に伴う低熱伝導率の状態でも、鋳型の軟化、変形
が起こらず、鋼の高速連続鋳造を円滑に行うこと
ができ、生産性も向上するという優れた効果を有
する。 [Industrial Application Field] The present invention relates to a method for manufacturing a tube mold material for continuous electromagnetic stirring steel casting. More specifically, the present invention relates to a method for manufacturing a tube mold material for continuous casting, which is used for continuous casting of steel, etc., equipped with an electromagnetic stirring device, and has physical and mechanical properties suitable for the mold material. [Background of the Invention] Recently, electromagnetic stirring has been adopted in continuous casting methods for steel and the like. As a result, the quality of ingots has improved, and it has become possible to continuously cast high-grade steel. However, with conventional mold materials used for continuous casting such as steel,
Because the proof stress at room temperature is less than 25Kgf/mm ² and the hardness is less than Hv85, if an electromagnetic stirring device is installed,
Compared to the casting method, the conditions for molds are extremely harsh, and there are problems in terms of strength and wear resistance. Cu, which was developed to solve this problem,
-Cr-Zr alloy has an electrical conductivity of 80% IACS, which is too high, and the magnetic field that is the energy source for electromagnetic stirring in the mold is absorbed, so a larger capacity power supply is required. As a result, problems arose, such as the need for large amounts of electricity during operation. In order to avoid these problems, Cu-Cr, which has low conductivity, excellent heat resistance and high temperature strength, has been developed.
Alloys such as -Zr-Al have been developed. However, when Cu-Cr-Zr alloy melts,
Since the molten metal is severely oxidized, atmospheric melting is extremely difficult and vacuum melting is required, which has the disadvantage of being expensive. Furthermore, in manufacturing, it is a prerequisite that it can be manufactured by a deoxidizing copper process or a process similar thereto. In addition, the mold is a large diameter tube (hot extrusion dimensions 189φ x 152φmm), and after hot extrusion, a variable speed processing process is performed to soften the strength and hardness and improve workability. Cold working and solution treatment at high temperatures are repeated. Due to such heat treatment, the secondary recrystallized grains become coarse, which causes drawing cracks in Cu-Cr-Zr alloys. [Objective of the invention] The conductivity of the mold material is set to 40 to 50% IACS, and the magnetic field from the electromagnetic stirring device is not consumed by the mold.
Furthermore, it eliminates softening and deformation of the mold due to a decrease in thermal conductivity due to a decrease in electrical conductivity, making it possible to perform high-speed continuous casting of steel etc. smoothly, improving productivity, and achieving a Witzkars hardness of 160 or higher and a softening temperature. is 425
The present invention provides a method for manufacturing a precipitation hardening mold material for electromagnetic stirring continuous casting of steel, which is made of a copper alloy having a temperature of at least .degree. [Summary of the invention] The gist of the present invention is that Ni0.4~2.0wt%, Si0.1~
0.4wt%, Zn0.05~1.0wt%, Mn0.02~0.1wt%,
Furthermore, when hot extruding a copper alloy ingot containing one or more of Mg, Cr, Zr, and Ti in a total amount of 0.001 to 0.1 wt%, and the balance being Cu and unavoidable impurities, The temperature increase rate when heating the ingot is 200°C/hour or more, and after hot extrusion, the ingot is cooled from 600°C or more at a rate of 5°C/second or more, and then the area reduction rate is 3. Cold working process at 5~30%, annealing process at a temperature of 600℃~800℃, and cooling process at a rate of 5℃/second or more.
Repeat the process two or more times, then reduce the area reduction rate to 5~
A method of manufacturing a pipe mold material for continuous electromagnetic stirring steel casting is provided, which is characterized by performing 30% cold working and then aging treatment. The method for producing a tubular mold material for electromagnetic stirring continuous casting according to the present invention will be explained in detail. First, the components contained in the tubular mold material for continuous electromagnetic stirring steel casting according to the present invention and the component ratios will be explained. Ni is an element that contributes to strength, and the content
If Si is less than 0.4 wt%, hardly any improvement in strength can be expected even if Si is contained in the range of 0.1 to 0.4 wt%. Moreover, if the content exceeds 2.0 wt%, the electrical conductivity will decrease, and furthermore, the effect of improving strength will be reduced. Therefore, the Ni content is set to 0.4 to 2.0 wt%. Si is an element that contributes to strength together with Ni.
If the Ni content is less than 0.1 wt%, high improvement in electrical conductivity and strength cannot be expected even if Ni is contained in a range of 0.4 to 2.0 wt%. Moreover, if Si is contained in excess of 0.4 wt%, the electrical conductivity decreases, and the hot extrusion workability and furthermore the cold workability after intermediate annealing are deteriorated. Therefore, the Si content is set to 0.1 to 0.4 wt%. Zn is an essential element for improving the peeling resistance of chrome plating and nickel plating, and if the content is less than 0.05 wt%, this effect is small. Moreover, if the content exceeds 1.0wt%, the peeling resistance of the plating will decrease. Therefore, the Zn content is set to 0.05 to 1.0 wt%. Mn is an element that improves hot extrusion processability. If the content is less than 0.02 wt%, this effect will be small, and if the content exceeds 0.1 wt%, the electrical conductivity will decrease. Therefore, the Mn content is set to 0.02 to 0.1 wt%. When hot extruding an alloy containing Ni and Si in the range mentioned above, either Mg is added to fix the free S present at the grain boundaries as MgS, or Cr, Ti, or Zr is added. It is necessary to strengthen the grain boundaries by adding . Mg is an element that stabilizes S that is inevitably mixed in from S and S compounds contained in raw materials, furnace materials, and the atmosphere during melting, and forms sulfur compounds with Mg to convert S to copper. Fixed in alloy.
In addition, Mg is necessary to strengthen grain boundaries and improve hot workability, and if the content is less than 0.001wt%, the desulfurization effect is small, and grain boundary cracks occur during heating or hot extrusion. becomes more likely to occur. Moreover, if the content exceeds 0.1wt%, Cu
and MgCu ₂ eutectic (722℃), this compound has a low melting point and deteriorates hot workability above 750℃, and furthermore, oxidizes the molten metal and significantly reduces the flowability. The ingot also becomes unsound. Cr, Ti, and Zr are elements that refine grains, improve high-temperature strength, and improve high-temperature elongation.
This is especially necessary to prevent cracking during hot extrusion. In addition, in cases where Mg is not included, Cr, Ti
If one or more of Zr and Zr is not included, cracking cannot be completely prevented, and if the content is less than 0.001 wt%, the above effect will be small. Also
If the content exceeds 0.1wt%, cracking during hot extrusion will be eliminated, but as the content increases, the effect of improving high-temperature strength will be reduced, and conversely the oxidation of the molten metal will become more intense. , it becomes impossible to obtain an ingot with a healthy cast surface. Therefore, the total amount of one or more of Mg, Cr, Zr and Ti selected from them is 0.001wt.
%~0.1wt%. Next, manufacturing conditions will be explained in detail. When hot extruding a copper alloy ingot with the composition range explained above, the temperature increase rate during heating is set to 200%.
The reason why the temperature is set at ℃/hour or more is to prevent heating cracking of the ingot during hot extrusion.
More specifically, when a copper alloy having the above-mentioned composition range passes through a medium-high temperature brittle region during heating, the grain boundaries tend to become brittle, and due to the synergistic effect of internal stress and thermal stress in the ingot, Heat cracking is likely to occur, making post-process manufacturing impossible. Therefore, it is desirable that the temperature increase rate of this alloy be as fast as possible during heating so that the temperature in the medium-high temperature brittle region can be passed quickly, and the rate is limited to 200° C./hour or more. Furthermore, after hot extrusion, cooling is performed at a rate of 5°C/sec or more from a temperature of 600°C or higher in order to maintain softness during solution treatment, and cooling is performed at a rate of 5°C/sec or more from a temperature of less than 600°C. Even if the cooling rate exceeds the
Even if it is cooled at less than 5°C/sec from a temperature of 600°C or higher,
This is because the above-mentioned effects are insufficient and workability in cold drawing in the subsequent process becomes poor. Next, the manufacturing process of the tubular mold material for steel electromagnetic stirring continuous casting is hot extrusion, cold drawing, solution treatment, and aging treatment. In cold working, in order to repeat drawing and tube expansion at harsh low processing rates,
Hardness and strength increase, and workability deteriorates. Therefore, solution treatment is required at least twice. Next, after cold working to an area reduction rate of 5% to 30%, 600
The reason for annealing at a temperature of .degree. C. to 800.degree. C. and cooling at a rate of 5.degree. C./second or more is to soften the material by solution treatment and improve workability in cold drawing and tube expansion. Furthermore, the reason for limiting the annealing and cooling temperatures is that when cooling from a temperature below 600°C, even if the cooling rate is 5°C/sec or more, the material in this state will already contain Ni and Si before starting cooling. Precipitation of compounds occurs, and sufficient solution treatment cannot be obtained.
It worsens subsequent cold workability. Even when cooling from a temperature of 600°C or higher, if the cooling rate is less than 5°C/sec, Ni and Si compounds will similarly precipitate during cooling, and sufficient solution treatment will not be obtained, resulting in subsequent Deteriorates cold workability. When annealing exceeds 800°C, even if the cooling rate is less than 5°C/sec or more than 5°C/sec, the crystal grain size grows significantly, causing grain growth, which causes intergranular cracking during cold drawing. Note that this intermediate annealing time is preferably 15 minutes to 2 hours. Furthermore, the aging treatment after finishing drawing of the mold material for steel electromagnetic stirring continuous casting according to the present invention is carried out at 400°C to 550°C.
Hardness and electrical conductivity can be improved by annealing at a temperature of 15 minutes to 5 hours. [Example] A copper alloy having the ingredients and proportions shown in Table 1 was melted under charcoal coating in a Kryptor furnace, and cast into a book mold type cast iron mold to a thickness of 45 mm.
An ingot with dimensions of mm x width 82 mm x length 200 mm was produced. Next, each ingot was cut and faceted to a thickness of 5 mm x width of 20 mm.
mm×length 180mm test piece for evaluating embrittlement characteristics under medium and high temperature, and thickness 35mm×width 75mm×length 200mm
A test piece for evaluation of workability was prepared. The evaluation test for embrittlement characteristics was performed using the three-point bending method at a stress of 10
Loaded with Kgf/ ^mm2 and 20Kgf/ ^mm2 , heated in a Kanthal furnace for 30 minutes at a heating rate of 800°C/3 hours and 800°C/4.5 hours, then rapidly cooled in water, and then inspected for cracks using a color check. did. The test piece for evaluating cold workability was 35 mm thick.
mm thick ingot was heated at a temperature of 860℃, the reduction rate of one pass was about 20%, and hot rolled to a thickness of 15mm in 4 passes, then quenched in water from a temperature of 650℃, and the hot rolling direction Sampled at right angles to, 10mm thick x 35mm wide
×Length 200mm, however, central parallel part length 80mm, width 25mm
A test piece was prepared. These specimens are
After 10~30% tensile processing, 30 at a temperature of 700℃
The specimens were annealed for 1 minute and then rapidly cooled in water from a temperature of 600°C twice, and the occurrence of cracks after each tensile process, the grain size and mechanical properties after the second annealing were examined. Furthermore, to investigate the final properties, the area reduction rate is 10 to 30.
% cold tensile material was subjected to aging treatment at a temperature of 450°C for 5 hours, and its Witzkars hardness and electrical conductivity were measured. Test results are shown in Tables 2 and 3. As is clear from Tables 2 and 3,
The process material of the present invention eliminates heat cracking, which is a problem in manufacturing tubular mold materials for steel electromagnetic continuous casting, and improves workability during hot extrusion. Suppresses grain growth caused by repeated drawing and tube expansion at a required low processing rate and high-temperature solution treatment,
It has become easy to produce with current equipment. That is, the alloy of the present invention produced by the process of the present invention is
Because it has excellent mechanical strength, electrical conductivity, and heat resistance, we have demonstrated that using it as a mold material for continuous electromagnetic stirring steel casting can significantly improve the life of the mold. ing. In addition to steel, the process material of the present invention is also suitable as a mold material for electromagnetic stirring continuous casting of copper alloys. [Effects of the Invention] As explained above, the mold material for electromagnetic stirring continuous casting of steel produced according to the present invention has the above-mentioned configuration, so that the conductivity is within the effective range for electromagnetic stirring. Even in a state of low thermal conductivity due to a decrease in electrical conductivity, the mold does not soften or deform, making it possible to perform high-speed continuous casting of steel smoothly and improving productivity. has.

【表】【table】

【table】

Claims

[Claims]

1 Ni0.4~2.0wt%, Si0.1~0.4wt%, Zn0.05~
1.0wt%, Mn0.02~0.1wt%, plus Mg, Cr, Zr
When hot extruding a copper alloy ingot containing one or more of Ti and Ti in a total amount of 0.001 to 0.1 wt%, with the remainder being Cu and unavoidable impurities, the ingot is heated. The heating rate at 200
℃/hour or more, and after hot extruding the ingot,
Cooling from 600°C or more at a rate of 5°C/second or more, then a cold working process with an area reduction rate of 5 to 30%,
The three steps of an annealing process at a temperature of 600℃ to 800℃ and a cooling process at a rate of 5℃/second or more are repeated two or more times, and then cold working is performed with an area reduction rate of 5 to 30%. 1. A method for manufacturing a pipe mold material for continuous electromagnetic stirring steel casting, the method comprising aging treatment after aging.