JPS6293081A - Manufacture of extremely thick-wall hollow material - Google Patents

Abstract

PURPOSE:To reduce manufacturing cost by forming a base material whose section is roughly a semi-circular arc shape by hot rolling, etc., and thereafter, forming an I-groove in both end parts of a pair of base materials by a fin pass device, and also welding both its end parts. CONSTITUTION:Rolling of a shape is executed by hot or warm rolling, and a base material 1 for a hollow material, whose section is a semi-circular arc shape is formed. Subsequently, a pair of base materials 1, 1 are charged into a fin pass device having a fin roller, both end parts 1a, 1b of the base material are brought to edge forming, respectively, and an I-groove is formed. Also, both the end parts 1a, 1b are welded by leading them into an induction welding device provided with an induction high frequency or medium frequency coil 25. In this case, electric seam welding is executed by pressing them from the outside of the base material by hourglass-shaped squeeze rollers 26, 27. According to this method, a flaw on the inner surface is checked easily, and the manufacturing cost of a dead thick-wall and long-sized hollow pipe can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing extremely thick hollow members used as strength members for mechanical structures, functional members for automobiles, structural members for automobiles, and the like.

<Conventional technology> In the past, when extremely thick-walled hollow members were required, the following methods were used.

■Normless Kushikan.

■ A solid piece of material that is perforated using a mechanical method.

■ ERW pipe.

However, the method for producing seamless copper tubes described in (2) involves rolling or pressing a steel ingot or piece of steel with a round or square cross section to form a hollow material, and then rolling or punching this hollow material. Since it is stretched, it has the following drawbacks. In other words, if t is the wall thickness of the hollow material and D is the outer diameter of the hollow material, it is extremely difficult to obtain a hollow material with t/D≧25% in a seamless copper pipe. In addition, the manufacturing cost is considerably higher than that of electric resistance welded pipes, and it is difficult to prevent and control internal flaws, resulting in a large uneven thickness.

Furthermore, in the method (2) of mechanically perforating a solid material, the manufacturing cost is extremely high compared to that of an electric resistance welded pipe, and long lengths cannot be obtained.

In addition, in the manufacturing method of ERW pipe (■), a steel strip is formed into a tubular shape at room temperature using multiple continuous rolls, and when this forming is finished, a low pressure is applied between electrode rings that contact the joints on both sides of the seam and rotate. High heat is generated at the joint through a large current alternating current, and when the forging temperature is reached, the joint is sealed tightly with a squeeze roll to join by electric resistance welding. There are some drawbacks. In other words, since it is molded at room temperature,
It is extremely difficult to obtain a material with t/D≧15%, and if it is forcibly formed, the roundness of the inner diameter will be affected and uneven thickness will occur.

<Object of the invention> Therefore, the object of this invention is to achieve t/D≧15%, as well as
Even when t/D≧25%, it is possible to obtain an extremely thick long hollow material with good roundness and little thickness deviation at a cost that is almost equivalent to that of an electric resistance welded tube, and moreover, it is free from internal defects. To provide a method for manufacturing an extremely thick-walled hollow karate that can be easily managed and checked.

<Structure of the Invention> In order to achieve the above object, the method for manufacturing an extremely thick hollow material of the present invention involves forming a material for a hollow material having a substantially semicircular arc cross section by hot or warm rolling. , A pair of the above-mentioned materials for hollow materials are loaded into a fin pass device in which a pair of fin rolls are installed facing each other, and the bevels at both opposite ends of the pair of hollow materials described in 1-1 are made 1". It is characterized in that it is edge-formed so as to be rounded, and then both ends of the pair of hollow material materials are welded.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

First, the shape is rolled in a hot (temperature state where the strength is 1./2 or less of the room temperature strength) or warm (a temperature state where the strength is 1/2 to 3/4 of the room temperature strength). , a hollow material material 1 having a semicircular arc cross section as shown in FIG. 2 is formed. The rolling for forming the hollow cable material 1 is equivalent to conventional steel section rolling, and can be performed at low cost. According to this form +4 rolling, if the wall thickness is made and the outer diameter is 1], any t/D can be obtained.
is possible.

In particular, it is possible to use a material with a small outer jMD. [Using materials or non-ferrous materials.

Material I for hollow material: Since the cross section is in the shape of a gutter with a semi-circular arc shape, quality control of the inner surface, especially inspection for surface flaws on the inner surface, is easier than inspecting the inner surface of a pipe.

Next, a pair of hollow material cables 1.1 (as shown in FIG. 3 or FIG. 4) are loaded into the f-pass device 3 or 4. This fin pass device 3 or 4 is similar to the fin pass device 5.6 of the conventional electric resistance welded tube manufacturing apparatus shown in FIGS. 5 and 6, but differs in the following points.

That is, in the fin pass device 3.4 used in the present invention, the fins 7a, 8a; IIa are provided at the center, respectively.

Fin roll 7.8 with 12a; II, 1
The conventional fin pass devices 5 and 6 have one fin roll 21 and 22 installed only in the upper part.

The fin pass device 3 forms a pair of hollow material material 1.1 into a pipe shape using two fin rolls 7.8, and uses fins 7a and 8a to form the upper and lower parts, that is, both ends 1 of the hollow material material 1.1.
A, Ia, lb, and Ib are edge-formed so as to form an I groove when joining. Similarly, the fin pass device 4 includes a fin roll 11.12 and a chain-shaped opening 13. When l=1, a pair of hollow material water (Ol.

1 into a pipe shape 1-1, hollow material material 1. Both ends 1a, Ia, Ib, Ib of I are fin roll II, 12 fins l 11. l Form two horns so that there is one groove when 2a7tf2 are combined.

Next, the welding process shown in Fig. 7.8 is introduced, and the pair of hollow material cables l, 1, and both ends 1a, la, lb are assembled.
.

1b is welded by induction welding, resistance welding, etc. Figure 7 shows the transmission welding method.

A high frequency or medium frequency current is passed through the induction coil 25 around 1. Then, heat the hollow material: 4'1.1, and
Ends Ia, Ia, lb on both sides of opening 5'e20,
When lb is forged and of good quality, press it from the outside with squeeze rolls 26 and 27, and press both ends I.
Welding a, la, Ib, lb. Figure 8 shows the resistance welding method, and the feeder
Apply current from ゜29 ('a, generate high heat at both ends Ia, la, Ib, lb of I groove 20)↓
“Tighten, squeeze roll 26. 27 to the outside 1;, press 7, - to the fat end ff1sIa, la, xb
, +h4 taji welding 4゛ro. Then, as shown in FIG. 9, an extremely thick hollow member is manufactured.

After the above welding, weld bead 3 shown in FIG.
I. Remove the paris by cutting etc.

In this way, the method for manufacturing the extremely thick-walled hollow material involves forming semicircular arc-shaped hollow material materials 1, 1 by hot or warm rolling, and then rolling a pair of fin rolls 7.8. ．． 1
1.12, a pair of hollow material materials 1. Both end portions 1a, la: Ib, l'b of L are formed by epoxy molding, and further the above-mentioned end portions 1a, la; Ib.

Since lb is welded, of course t/D≧15% and t/D
A hollow material with an extremely thick wall of ≧25% can be manufactured at low cost, and it is also possible to easily check for defects on the inner surface of the hollow material material 1°1 having a semicircular arc cross section before welding.

<Effect of the invention> As is clear from the above, according to this invention, t/D≧
Not only 15%, but also t/D≧25%, it is possible to obtain an extremely thick long hollow material with good roundness and little unevenness of thickness at approximately the same cost as electric resistance welded pipe. , internal flaws can be easily managed and checked.

Further, according to the present invention, it is possible to easily obtain a very thick-walled hollow material even if it has a small diameter.

[Brief explanation of drawings]

FIG. 1 is a side view showing the material for the hollow material used in this invention, FIG. 2 is a front view of the material for the hollow material, and FIGS. 3 and 4 show the fin pass device used in each embodiment of the invention. 5 and 6 are respectively front views of the conventional fin pass device, 7 and 8 are perspective views illustrating the welding method, respectively, and 9 is a front view of an extremely thick hollow member. It is. ■...Material for hollow material, 3,4,5.6...Fin pass device, 7,8,11,12.21.22...Fin roll. Patent Applicant Kobe Steel Co., Ltd. Representative Patent Attorney 28 Yu Soto 1i11
NFebruary 7th Tate 8th Prisoner Figure 9

Claims (1)

[Claims] (1) A fin path in which a hollow material with an approximately semicircular arc cross section is formed by hot or warm rolling, and a pair of fin rolls are installed to face the hollow material. The method is characterized in that the pair of hollow material materials is charged into a device, edge-formed so that opposite ends of the pair of hollow material materials form an I-groove, and further, both ends of the pair of hollow material materials are welded. A method of manufacturing an extremely thick hollow material.