JPS62212040A - Production of bending mold for continuous casting - Google Patents

Abstract

PURPOSE:To easily produce the titled special Cu-alloy mold having high characteristics by making a tube-shape material by electron-beam-welding of bended cutting edge parts of the rolling pate having a little thicker than the mold thickness, and executing drawing and bending works as becoming the welding line as center line. CONSTITUTION:The rolling plate 1 of heat resistance, high strength, wear resistance special Cu-alloy, having a little thicker than the finished thickness is bended 2 as the prescribed shape and its edge part is cut, to make the welding easily. The electron-beam-welding W is executed as coming together face to face of the edge parts of the bended materials 2 to make the tube-shape material 3. A die-drawing and bending-drawing works are executed to the tube-shape material 3 as becoming the welding line W as center line of the works, to minimuze addition of the tensile and compressive stresses caused by bending at the welding part W and heating effective part, and to prevent the development of the defects. The high characteristics special Cu-alloy bending mold with hard workability for the continuous casting is produced comparatively at easy and stable. Further, the circular type bending mold is also produced by the same process.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a mold for continuous casting, and in particular to manufacturing an integral mold for continuously molding round or square billets, blooms, etc. into curved shapes. 0 Regarding Methods (Prior Art) FIG. 3 shows the manufacturing process of a curved mold for rectangular continuous casting according to the prior art. In this case, it is necessary to use phosphorus deoxidized steel, which has been commonly used, as the mold material. Phosphorus-deoxidized copper has excellent hot and cold workability, and it is possible to produce seamless pipes by hot extrusion or hot perforation. Seamless raw pipe (
bl is hot produced. This is cold-drawn to the required thickness and dimensions to form a right-angled cylinder (CL), which is then bent to form a curved cylinder (DL), which is then subjected to finishing processes such as machining and plating to form a completed curved mold tel. shall be.

In special cases, a mold may be created by electrodeposition of copper, or a roughly cylindrical or rectangular tube may be formed by casting, and then machined into the final mold shape.

(Problems to be solved by the invention) In recent years, with the improvement of continuous casting technology, the requirements for heat resistance, wear resistance, etc. for the υ1 type have become stricter, and phosphorus deoxidized copper cannot sufficiently meet these requirements. Can not. Therefore, we possess the necessary characteristics of continuous casting molds such as electrical conductivity and thermal conductivity,
It is necessary to form an integral continuous casting mold using a special copper alloy that has superior heat resistance and wear resistance.

However, special copper alloy materials that have all of these properties are generally difficult to hot or cold work, and it is almost impossible to form seamless pipes by hot drilling or extrusion. The conventional method shown in the figure cannot be adopted. Even if this could be done using other construction methods, the cost would be extremely high. Furthermore, electroforming cannot produce a sound structure for alloys with complex compositions.

The present invention solves the above-mentioned problems of the prior art and provides hot extrusion,
Using a special copper alloy with heat resistance, high strength, and wear resistance that is difficult to drill, it is possible to form a one-piece curved mold for continuous casting.
The purpose is to provide a manufacturing method that allows stable production at low cost.

(Means, effects, and embodiments for solving the problems) The above object is to heat a base plate of a mold material having a slightly larger thickness than the final wall thickness as a curved mold for continuous casting according to the present invention. This is accomplished by first rolling the blank material, then bending it using a press or the like to obtain a bent material, and then joining the ends of the bent material by electron beam welding to form a cylindrical material.

Hereinafter, the present invention will be specifically explained in detail with reference to the accompanying drawings. FIG. 1 is an example of manufacturing a rectangular curved mold.

(As mentioned above, the raw material manufacturing material 11 is a hard and brittle material made of a special copper alloy with low hot deformability. A cast slab of this material is mainly hot-rolled and cold-rolled to produce the raw material (1). The thickness of the blank material (1) is slightly larger than the final thickness of the curved mold, taking into account the thinning caused by cold drawing in the subsequent process.

Due to its mechanism, hot rolling is more suitable for processing hard and brittle materials than extrusion or perforation, and cracks are less likely to occur due to the balance of generated stress.

Further, by incorporating a face shaving process into the rolling process, a blank material with excellent surface quality can be obtained. In the case of precipitation hardening alloys, solution treatment is performed after cold rolling.

+11 Bending of the raw material The raw material (1) is cut into a predetermined size, and then bent using a press using a mold to form a bent material (2). After bending, the ends are trimmed using a milling cutter or the like.

fll) Welding of bent materials The ends of a pair of bent materials L2) +2) are joined together by electron beam welding to form a cylindrical material (3). By adopting electron beam welding as the welding method, uniform penetration can be obtained over the entire wall thickness.
The Z section can be made narrower or smaller so as not to impair the strength of the base material. After welding, in order to make the processing rate uniform in the next process of cold drawing, the pead part is shaved off to have the same thickness as the base metal part.

(Cold drawing process of cylindrical material) Linear mold material (4) which has been cold drawn from the above cylindrical material [3] to give it dimensional accuracy and characteristics as a mold.
shall be.

The bending process of the blank material (1) can be used to form the cylindrical material (3) into the desired shape and dimensions depending on the mold, so cold drawing of the cylindrical material can freely select the processing rate and achieve satisfactory properties as a mold. , it is possible to perform the most suitable cold drawing to reach the precision. The processing rate required to provide the desired properties and surface quality is preferably 10 to 50 inches. Although cold drawing of hard and brittle materials itself is not easy, the above-mentioned processing rate can be achieved by drawing once or a minimum number of times. The present invention does not require the complicated steps of conventional extrusion and drawing of a perforated material from a round shape into a rectangular mold shape.

(Vl Curving processing of straight mold material The mold material (4) is curved so that the weld line +wl becomes the neutral line of bending to obtain a curved mold material (5).

By setting the weld line (wl) as the bending neutral line position where tensile and compressive stresses are 0 as a specific bending direction, the addition of tensile and compressive stress due to bending to the welded part and heat affected zone is minimized, Even if a spot defect such as a pinhole occurs due to welding, it can be prevented from becoming a decisive defect in product quality.

Precipitation hardening alloys are subjected to precipitation hardening treatment after bending to impart predetermined properties.

(VD Finishing processing for continuous casting mold) Finishing processing such as end face cutting, mounting groove processing, and inner surface plating is performed on the curved mold material (5) to complete a continuous VC casting curved mold (+3).

FIG. 2 is an example of manufacturing a round curved mold by the method of the present invention.

This is substantially the same as the production of the rectangular curved mold described above, and each equivalent part will be indicated by the same reference numeral with the suffix A, and repeated explanation will be omitted. In the round example, the base material (1A
), bent material (2A), welding line (- is 1 for each, and the difference is that the cylindrical material (5A) is cylindrical.

(Effects of the Invention) According to the present invention, a curved mold for integral continuous casting can be relatively easily stabilized at low cost using a special copper alloy material with heat resistance, high strength, and wear resistance that is difficult to hot extrude and drill. It is effective in improving continuous casting technology and improving productivity.

[Brief explanation of drawings]

FIG. 1 shows one of the manufacturing methods of the present invention for a rectangular curved mold.
The second is a diagram showing the process order of the other side of the manufacturing method of the present invention for a round curved mold, and FIG. 5 is a process sequence diagram of the manufacturing method of the prior art. (1) CIA)...Material, (z) (2A)...Bending material, +31 (5A)...Cylindrical material, (4) (4
A)... Straight mold material, (5) (5A)... Curved mold material,
+6) (6A) --Curved mold, (wl...welding Ai
, (al...° billet, (b)... seamless pipe, (cl... right angle tube, (di... curved tube, (el... curved mold).

Claims (2)

[Claims] (1) A blank material for a mold having a thickness slightly larger than the final wall thickness for a curved mold for continuous casting is manufactured by rolling, and the blank material is first bent by pressing etc. to form a bent material. 1. A method for manufacturing a curved mold for continuous casting, characterized in that the ends of the bent material are then joined by electron beam welding to form a cylindrical material. (2) The method for manufacturing a curved mold for continuous casting according to claim 1, wherein the mold material is a hard and brittle material that is difficult to mold into a seamless hollow member.