JPS6293060A

JPS6293060A - Production of casting tool

Info

Publication number: JPS6293060A
Application number: JP23223785A
Authority: JP
Inventors: Hiroshi Takara; 高良　拡; Yoshimi Murase; 好美村瀬
Original assignee: Daido Steel Co Ltd
Current assignee: Daido Steel Co Ltd
Priority date: 1985-10-17
Filing date: 1985-10-17
Publication date: 1987-04-28
Anticipated expiration: 2009-05-25
Also published as: JPH0638977B2

Abstract

PURPOSE:To maximize the joint strength of two parts in production of a tool by a multiple casting method by melting at least the surface of the 1st cast metallic ingot by the previously poured molten metal, which contacts the 2nd molten metal, by the sensible heat of the 2nd molten metal. CONSTITUTION:The melt 1 of the 1st metal is poured into a casting mold 5 in the stage of producing, for example, a guide shoe. The melt 2 of the 2nd metal is poured into the mold after the surface layer 11 thereof solidifies and before the inside 12 is not solidified yet. At least the surface of the cast ingot of the 1st metal, which contacts the molten metal 2, and preferably the entire contact part are melted by the sensible heat of the molten metal to obtain an integral casting 7. The casting tool which has high durability and obviates the anxiety in use is obtd. according to the above-mentioned method.

Description

【発明の詳細な説明】[Detailed description of the invention]

発明の目的［産業上の利用分野１本発明は鋳造工具の製造方法の改良に関する。本発明は製管用工具、とくにガイドシューの製造に適用
したとき、この意義が大きい。［従来の技術］継目無鋼管の製造に使用するガイドシューなどの工具は
、高温下に強い衝撃を受けるので、造管用材料と接触す
る表面は耐摩耗性および耐焼付性を有することを、また
本体は靭性を有することを要求される。従来、この要求にこたえるためにはガイドシュ一本体を
鋳鋼で製造し、接触面にステライトなどの硬質合金を肉
盛り溶接することが行なわれていた。　しかし、硬質の
合金の肉盛り溶接は多大の労力を必要とする作業である
し、肉盛り面の仕上げ研摩も必要であるから、ガイドシ
ューは高価なものになる。そこで、もっと簡易に鋳造工具を製造する方策として、
多重鋳造が試みられるようになった。多重鋳造は、たとえばカイトシューの鋳型の造管用材料
と接触する表面部分を下方にした位置で鋳型を置き、耐
摩耗性および耐焼付性のすぐれた合金たとえば３５Ｃｒ
　−３５Ｎｉ　−３Ｍｏ合金の溶湯を、鋳型空所の下方
を満たす量だけ注入して鋳造し、次に残った鋳型空所上
方に靭性の高い鋳鋼の溶湯を注入して鋳造し、一体化し
た鋳造品を得る、といった方法である。多重鋳造の問題点は、ひとつは合金部分と鋳鋼部分との
接合に不安があることであり、いまひとつは、両者の境
界が水平に形成されるので、ガイドシューの曲面の両端
よりの部分に必要以上の合金が使用され、不経済である
ばかりか、全体の靭性にとってはマイナスになることで
ある。後者の問題の解決策として、合金で必要な部分に応じた
形状のものを別の鋳型で鋳造しておき、それをガイドシ
ュー鋳型内に置いて鋳鋼の鋳造を行なうことが提案され
た。　その際に前者の問題の解決を、つまり上下の部分
の接合強度を高く得る目的で、鋳鋼の溶湯を合金鋳物の
表面に流してその温度を高めることをはかった技術もあ
る（特開昭５９−２２０７１号）。しかし、この方法は鋳型内に大きな湯だまりを設けて大
量の鋳鋼溶湯を捨て湯としなければならず、不経済であ
る。［発明が解決しようとする問題点］本発明の目的は、多重鋳造法による工具の製造において
、二つの部分の接合強度を最大限にし、使用上不安のな
い耐久性の高い鋳造工具、とくにガイドシューを製造す
る方法を提供することにある。発明の構成［問題点を解決するための手段１図面を参照して説明すれば、本発明の鋳造工具の製造方
法は、第１図に示すように、鋳型５内にその一部を満た
すように第一の金属の溶湯１を注入し、第２図に示すよ
うにその表層１１が凝固し内部１２が未凝固の間に、第
３図に示すように第二の金属の溶湯２を注入し、第二の
金属溶湯２の顕熱をもって、少なくとも前記第一の金属
の鋳塊の第二の金属の溶湯２との接触面を、好ましくは
図示したように接触部の全体を溶融し、結果として第４
図に示すような一体の鋳造物７を得ることを特徴とする
。第一の金属としては、その鋳造工具に要求される性能に
応じて、耐摩耗性、耐焼付性、耐熱性などの特性をもっ
たものをえらぶ。　具体的な例は、ステライトのような
ＣＯＷ超合金、ハステロイのようなＮｉ基超超合金３５
Ｃｒ　−３５Ｎｉ　−３Ｍ０合金などである。第二の金属は、靭性の高いものであって、たとえばＳＣ
Ｈ１３（代表的には０．３Ｃ−２５Ｃｒ−１２Ｎｉ　−
Ｆｅ　）が好適でおるが、もつと廉価な鋳鋼であっても
よい。一般に第一の金属は第二の金属にくらべて高融点である
ことは避は難いが、融点の差は１５０℃以内、できれば
１００′Ｃ以内に止めたい。［作用１本発明に従って多重鋳造を行なえば、第一の金屈と第二
の金属とが溶湯状態で接触し部分的に混合するから、上
下部つの部分の接合は完全となり従来の多重鋳造の弱点
であった接合強度の不安は解消する。前記したところから理解されるとおり、本発明の方法の
成否は、第一の金属の溶湯がどの程度凝固したところで
第二の金属の溶湯を注入するとよいか、というタイミン
グにかかつている。　いうまでもなく、タイミングが遅
れると接合が不完全となって本発明の効果が得られない
が、早すぎても第一の金属の凝固層の厚さが不十分とな
るおそれがある。鋳造工具が継目無鋼管製造用のガイドシューである場合
、第一の金属の溶湯を注入したのち、通常は６分以内に
第二の金属の溶鋼を注入することによって、上記した一
体化が行なわれる。OBJECT OF THE INVENTION [Industrial Application Field 1] The present invention relates to an improvement in a method for manufacturing a casting tool. The present invention has great significance when applied to the manufacture of pipe-making tools, especially guide shoes. [Prior Art] Tools such as guide shoes used in the manufacture of seamless steel pipes are subjected to strong impacts at high temperatures, so it is important that the surfaces that come into contact with pipe-making materials have wear resistance and seizure resistance. The main body is required to have toughness. Conventionally, in order to meet this requirement, the main body of the guide shoe was manufactured from cast steel, and a hard alloy such as stellite was overlaid and welded to the contact surface. However, build-up welding of hard alloys requires a lot of labor, and the build-up surface also requires finishing polishing, making the guide shoe expensive. Therefore, as a way to manufacture cast tools more easily,
Multiple casting began to be attempted. In multiple casting, for example, the mold is placed in a position with the surface part of the kite shoe mold that contacts the pipe-making material facing down, and an alloy with excellent wear resistance and seizure resistance is used, such as 35Cr.
-35Ni -3Mo alloy molten metal is injected in an amount that fills the lower part of the mold cavity, and then molten cast steel with high toughness is poured into the upper part of the remaining mold cavity and cast. This is a method of obtaining goods. One of the problems with multiple casting is that there is a problem with the joint between the alloy part and the cast steel part, and the other is that the boundary between the two is horizontal, so it is necessary for the part from both ends of the curved surface of the guide shoe to The use of the above alloys is not only uneconomical, but also has a negative impact on the overall toughness. As a solution to the latter problem, it has been proposed to cast an alloy with a shape corresponding to the required part in a separate mold, and then place it in a guide shoe mold to cast steel. At that time, in order to solve the former problem, that is, to obtain a high joint strength between the upper and lower parts, there is a technique in which molten steel is poured onto the surface of the alloy casting to raise its temperature (Japanese Patent Laid-Open No. 59-2011). -22071). However, this method is uneconomical because it requires a large pool of molten steel to be disposed of in the mold. [Problems to be Solved by the Invention] The purpose of the present invention is to maximize the bonding strength between two parts in the production of tools by the multiple casting method, and to provide a highly durable casting tool that can be used safely, especially a guide. An object of the present invention is to provide a method for manufacturing shoes. Structure of the Invention [Means for Solving the Problems 1] To explain with reference to the drawings, the method for manufacturing a casting tool of the present invention is to fill a part of the mold 5 as shown in FIG. A molten metal 1 of the first metal is injected into the molten metal 1, and while the surface layer 11 is solidified as shown in FIG. 2 and the inside 12 is unsolidified, the molten metal 2 of the second metal is injected as shown in FIG. and melting at least the contact surface of the first metal ingot with the second metal molten metal 2, preferably the entire contact portion as shown, using the sensible heat of the second metal molten metal 2, As a result, the fourth
It is characterized by obtaining an integral casting 7 as shown in the figure. As the first metal, one with characteristics such as wear resistance, seizure resistance, and heat resistance is selected depending on the performance required of the casting tool. Specific examples include COW superalloys such as Stellite, and Ni-based superalloys 35 such as Hastelloy.
Cr-35Ni-3M0 alloy, etc. The second metal has high toughness, for example, SC
H13 (typically 0.3C-25Cr-12Ni −
Although Fe) is preferred, inexpensive cast steel may also be used. Generally, it is inevitable that the first metal has a higher melting point than the second metal, but it is desirable to keep the difference in melting point within 150°C, preferably within 100'C. [Operation 1] When multiple casting is performed according to the present invention, the first metal and the second metal come into contact in a molten state and are partially mixed, so the upper and lower parts are completely joined, which is different from the conventional multiple casting. Concerns about joint strength, which was a weak point, are resolved. As can be understood from the foregoing, the success or failure of the method of the present invention depends on the timing at which the molten metal of the first metal has solidified before the molten metal of the second metal is injected. Needless to say, if the timing is delayed, the bonding will be incomplete and the effects of the present invention cannot be obtained, but if the timing is too early, the thickness of the solidified layer of the first metal may become insufficient. When the casting tool is a guide shoe for the manufacture of seamless steel pipes, the above-mentioned integration is achieved by injecting the molten steel of the second metal, usually within 6 minutes, after injecting the molten steel of the first metal. It will be done.

【実施例】【Example】

継目無鋼管製造用のガイドシューを、図面に示す工程で
製造した。　第一の金泥としてステライトを、第二の金
属としてＳＣＨ１３をえらび、ステライトをその注入最
小厚さが２５馴となるよう、　　に注入し、ついで約１
２０秒の間隔をおいて５Ｃ）１１３を注入した。一体に得た鋳造物は、ガイドシューとして高い耐久性を
示した。　切断して上下部分の境界をしらべたところ、
約８Ｍｒ１の厚さにわたって２種の溶湯が混合した層が
あり、接合の完全さを示していた。Ｒ皿Ω諮】本発明の製造方法によれば、多重鋳造による鋳造工具が
第一および第二の金属の完全な接合の下に製造できる。　一体の鋳造物の内部にはヒケや巣が発生しないことも
あって、この工具は強固である。　第一の金属の層は必
要最小限の厚さに形成すればよいから、材料費が節約で
きる上に、第二の金属が本体の大部分を占めるため強靭
である。この工具の使用により、製管作業のコストが低減できる
。本発明の製造方法は、具体的に説明した製管用ガイドシ
ューのほか、同種の性能を要求される鋳造工具の製造に
適用できる。A guide shoe for manufacturing seamless steel pipes was manufactured using the process shown in the drawings. Stellite was selected as the first gold mud and SCH13 was selected as the second metal, and the stellite was injected so that the minimum injection thickness was 25 mm, and then about 1 mm.
5C) 113 was injected at 20 second intervals. The integrally obtained casting exhibited high durability as a guide shoe. When I cut it out and examined the boundaries between the upper and lower parts,
There was a layer of mixture of the two molten metals over a thickness of approximately 8 Mr1, indicating the integrity of the bond. According to the manufacturing method of the present invention, a casting tool by multiple casting can be manufactured with perfect joining of the first and second metals. This tool is strong, as there are no sink marks or cavities inside the one-piece casting. Since the first metal layer only needs to be formed to the minimum necessary thickness, material costs can be saved, and the second metal layer occupies most of the main body, making it strong. Use of this tool can reduce the cost of pipe manufacturing operations. The manufacturing method of the present invention can be applied not only to the specifically explained pipe-making guide shoe but also to manufacturing casting tools that require the same type of performance.

【図面の簡単な説明】[Brief explanation of drawings]

図面はいずれも本発明の方法により製管用ガイドシュー
を製造する工程を説明するための断面図であって、第１図は、鋳型内に第一の金属の溶湯を注入した段階、第２図は、上記第一の金属の溶湯の表面が凝固した段階
、第３図は、その上に第二の金属の溶湯を注入した段階を
それぞれ示し、第４図は、このようにして製造したガイドシューの内部
構造を示す。１・・・第一の金属の溶湯１１・・・表層　　　　１２・・・内部２・・・第二の
金属の溶湯５・・・鋳型　　　　　７・・・鋳造物特許出願人　　
　大同特殊鋼株式会社代理人　　弁理士　　須　賀　総　大筒１！１第２ｔｌThe drawings are all cross-sectional views for explaining the process of manufacturing a guide shoe for pipe making by the method of the present invention, and FIG. 1 shows the stage where the molten metal of the first metal is poured into the mold, and FIG. 3 shows the stage where the surface of the molten metal of the first metal is solidified, FIG. 3 shows the stage where the molten metal of the second metal is injected thereon, and FIG. 4 shows the guide manufactured in this way. The internal structure of the shoe is shown. 1... Molten metal of first metal 11... Surface layer 12... Inside 2... Molten metal of second metal 5... Mold 7... Casting patent applicant
Daido Special Steel Co., Ltd. Agent Patent Attorney Suga So Otsutsu 1!1 2nd TL

Claims

【特許請求の範囲】[Claims]

（１）鋳型内にその一部を満たすように第一の金属の溶
湯を注入し、その表層が凝固し内部が未凝固の間に第二
の金属の溶湯を注入し、第二の金属の溶湯の顕熱をもっ
て、少なくとも前記第一の金属の鋳塊の第二の金属の溶
湯との接触面を溶融し、一体の鋳造物を得ることを特徴
とする鋳造工具の製造方法。(1) Pour the molten metal of the first metal into the mold to partially fill it, and while the surface layer is solidified and the inside is unsolidified, pour the molten metal of the second metal. A method for manufacturing a casting tool, characterized in that at least a surface of the ingot of the first metal in contact with the molten metal of the second metal is melted using sensible heat of the molten metal to obtain an integral casting.

（２）第一の金属が、耐摩耗性、耐焼付性および耐熱性
の少なくとも１種の性質を有するものであり、第二の金
属が靭性の高いものである特許請求の範囲第１項の製造
方法。(2) The first metal has at least one of wear resistance, seizure resistance, and heat resistance, and the second metal has high toughness. Production method.

（３）第二の金属の融点と第一の金属の融点との差が１
５０℃以内である特許請求の範囲第１項の製造方法。(3) The difference between the melting point of the second metal and the first metal is 1
The manufacturing method according to claim 1, wherein the temperature is within 50°C.

（４）第一の金属が、Ｃｏ基超合金、Ｎｉ基超合金およ
び３５Ｃｒ−３５Ｎｉ−３Ｍｏ合金からえらんだもので
あり、第二の金属がＳＣＨ１３である特許請求の範囲第
２項の製造方法。(4) The manufacturing method according to claim 2, wherein the first metal is selected from a Co-based superalloy, a Ni-based superalloy, and a 35Cr-35Ni-3Mo alloy, and the second metal is SCH13. .

（５）鋳造工具が製管用ガイドシューであって、造管用
材料と接触する面に前記第一の金属が存在するように鋳
造する特許請求の範囲第１項の製造方法。(5) The manufacturing method according to claim 1, wherein the casting tool is a pipe-making guide shoe, and the casting tool is cast so that the first metal is present on the surface that contacts the pipe-making material.