JPS58103937A - Production of hollow steel ingot - Google Patents

Abstract

PURPOSE:To reduce the number of steps for production of hollow steel ingots considerably and to improve yield by inserting a mandrel formed with a release layer on the outside surface in molten steel and molding the insert steel ingot to a prescribed shape then removing the mandrel thereby obtaining a hollow steel ingot. CONSTITUTION:A mold releasing agent 32 is coated on the outside surface of a mandrel 31a to form a core 3a. The material 32a consists of fine particulate or fibrous refractory materials incorporated with inorg. binders. The prepared core 3a is installed in the center of a mold 2. Molten steel 9 of a base material is introduced into the mold through a runner 6a to perform internal chill. Upon ending of insertion, the steel ingot is rolled to a steel ingot having a prescribed sectional shape and both end parts of the ingot are cut, then the mandrel 31a is removed. Thus, the hollow ingot having good quality is obtained and the life of cutting tools is prolonged.

Description

[Detailed description of the invention] This invention relates to a method for manufacturing hollow steel pieces.

In order to manufacture a hollow steel billet, a solid steel ingot is ground, the steel billet is returned, and a hole is drilled in the center of this steel billet to fit the dimensions of the product to produce a hollow steel billet. Was. In addition, another method is to obtain soft steel slabs by taming Chuyi Steel Todoroki! # Drill a hole in the center of the surface, insert the core bar coated with anti-adhesion agent, and make both ends 11IIl! This is a method in which the steel piece containing the fund is turned into a liL shape with a predetermined llIr surface shape, and the core bar is extracted from the processing machine.

However, the first method described requires a fairly large diameter round hole to be formed along the entire length of the steel billet, and the second method requires a smaller diameter hole compared to the first method, but Holes had to be drilled along the entire length of the billet. In this way, one or more of the two conventional methods all require very sophisticated technology and large ridges, and also have large walking losses, short cutting tool lifespans, and poor rework.

Therefore, one purpose of the present invention is to resolve the shortcomings of these conventional construction methods and improve the yield by reducing the number of machines. Qinbian l!
Method II is provided up to 4.

According to the present invention #4, a core bar with a peeling layer formed on the outer surface is cast, the cast iron ingot is molded into a predetermined shape, and the core bar is extracted to obtain a gushing hollow steel piece. It is.

The present invention will be explained below with reference to some examples of the present invention shown in the drawings.

all 1 m (Tsuru (1)) [Core 5 as shown
The outer surfaces of 111.311 are coated with peeled lI copper 52a, 52b to form cores 5a, 5b. This stripping agent 52a
,! As will be described below, i2b is a product made of particulate or fibrous refractory material with an inorganic binder. The core 5* and sb thus created are II s Fixt (a
), am is placed at the center of mat2 shown in (b).

Here, the mold 2 shown in Figure 5#A (&) is for a core without a hawk, and the core Sa shown in Figure 1 (1) is used.

1wl, in the case of the bottom core of III B ilQ (b), the value of core 5b of theory 11N (1)) will be lowered. In this way, the core Sa.

After installing 5b, the base metal chain 9 is used for casting.

Furthermore, the steel ingots of the finished cast statues were placed in a prescribed order so that they would become one piece of the dimensions, and the fall shown in Figures 4 (a) and (b) in #.
In this state (1), the core metal 51' is separated from the base metal molten steel 9 by the feeding steel 52'. Stripped copper 12' is mother #
During casting with Minato Steel 9 and subsequent heating, a hard sintered layer is created and rolled into a 118-metal shape.

After rolling, both sides of the steel slab are cut at the positions indicated by 10 in Figure 1W44 (IL), and the core bar 311 is attached. This time, remover 1
2' has been broken and crushed by rolling as described above, so the peelability between the inward steel billet 91 and the core bar 31' is improved. The only way to survive is to extract Kim 51. Furthermore, since this release agent uses an inorganic binder, the amount of gas generated during casting is suppressed, and a steel ingot with good inward skin can be obtained.

In addition, as shown in 3rd 211iQ e) s(b), release agents 42m and 421* are formed on the outer part of the core bar 411° and 4111, and thin steel plates 4a and 4b are further attached to the outer periphery of the material.
It is also possible to adopt a 4m or 4k core. Even in this case, casting in the base material chain 9, rolling to a predetermined llT surface dimension, cutting, and handling of the core bar are performed in the same manner as described above. Here, the thin steel plates 45&, 4S'ta whose outer surfaces of the release agents 42&, 42b have been removed are welded to the inner surface of the steel piece 9' due to the retained heat of the image scale 9.

For this reason, during casting, the release agent is rolled into the molten steel and causes large inclusions.

In this article, each process of the method for manufacturing a hollow steel billet according to the present invention has been explained in detail, and experimental data will be shown and discussed below.

(1) Place the core (core metal and release agent) shown in Table 1 below in the center of the mold, and change the release agent thickness and composition.

This was cast with a base material chain, and a 5* core cast steel ingot was made.

A: 810. =85.7, Az, 0. =1.
0, F~OI plot 0.9.

Water glass containing sodium silicate 32- as an inorganic binder is added to a particulate fibrous refractory material of Cgl, 0, NIL, O.K., Os = 4.7 and molded. (Spray-cloth is also possible a> B: Mgo=85j, in, O@jw1,9
, Caoz2,2, Cr-1,5゜Ha-・K,
It is produced by adding water glass containing 52 g6 of sodium silicate as an inorganic binder to a mold particle fibrous refractory material of No. 085.8. (Spray M cloth is also possible) The test was conducted using 8CM5 for both Asahi 1 to S as the material of the base material and submerged steel.

(2) A steel ingot containing a cored metal is cut into a specified size using a blocker machine (Roll 4!! 1020 mm φ), cut into a certain length, and the cored metal is removed. The outer surface of the steel piece was cut to obtain a predetermined hollow steel piece. The conditions of each tank are shown in fi2.

In addition, the soaking temperature is 1270℃, the heating time is 11.5H.
``I heated it up.

For Kukenzu 1 and 5, the core metal could be removed easily, but for core metal 2, because the thickness of the release agent was small, there was a partial pressure skin between the core metal and the base material, and the core metal was removed. Since it is impossible to extract the gold, the dimensions of the hollow steel piece of the core metal treatment moat in Table 1 and the inner and outer rk@cuts were determined using a needle tool by drilling the holes. It can be seen from the above that the thickness of the release agent is required to be at least 1.0 mm or more in the case of screw threads of steel pieces with cored metal.

Although there are some unevenness in the inward facing condition of the bales from which the core metal is removed due to the pushing of the release agent, there is very little adhesion and there are almost no blowholes because a stronger sintered layer is formed compared to when organic caking copper is used. Who? Due to eccentricity of the core metal, it is necessary to partially cut and remove it.
0 - It must be cut to a red eye.

Therefore, the yield loss in this case is 7.5, including external cutting.
The angle is 964 degrees, but compared to the conventional method, the angle is reduced by 12S, making it possible to achieve a significant improvement in walking distance.

We also looked at the effect of thin steel plates in N11.5.

When looking at the inclusions near the introversion, both 1111 and 1111 were particularly open.
However, in NIILs, the C-intermediate Il+ (810, yarn) obtained by the A8TM-A method is dry.
However, this is not the case and the effect of thin steel sheets is evident. Other than that, there was no difference in the unevenness of the meat or the quality of the meat.

The method for manufacturing a hollow steel billet according to the present invention is as described above, and can bring about the following effects.

It is possible to produce a useful hollow steel billet that can significantly reduce the number of man-hours, improve the yield because there is no quantity theory in quality, and extend the life of the cutting tool.

Table 1 Note) Release agent set IE 45G) Table 2

[Brief explanation of the drawing]

Figure 1 (Shizu (1)) is a cross-sectional view E1 showing the core, and Figure 2 (a
), Italy) is a cross-sectional view showing the outer surface of the mat with a thin plate, and N45 diagram (a) * (b) is a cross-sectional view of the mold.
(IL) is a vertical cross-sectional view of a steel ingot, Italy) is an inspection cross-sectional view, FIG. 1a, 1b * *Surface plate, 2--@141.5a, !i
b@・Nakako,! 116.11b-8 core metal, 52 &, 52
ba *Removal agent, 4&, 4b** Core, 41m, 41b
, # Core metal, 426.42b...Removal agent, 45a, 4
5b... Thin steel plate, 5&, 5tl** support Zen, 6*, 6b
-a Yudo. 7a, 7b, 7c...Gate, 8...Riser frame, 9...Base material chain, 10...Cutting position. Patent issuer: Sumitomo Metal Industries Co., Ltd. Tomohisa Kado

Claims (1)

[Scope of Claims] (凰) A layer 11III consisting of a particulate or fibrous refractory material and an inorganic binder is formed on the outside of the core metal, and this layer is placed at the center of the casting material. # Molten steel - Gurumi,
A method for manufacturing a hollow steel billet, which involves punching out the IiL-shaped image core from this cored steel ingot into a predetermined shape. (2) A peeling layer consisting of a particulate or fibrous refractory material and an inorganic thickening agent is formed on the outer side of the core metal, and a thin steel plate is further placed outside the peeling layer, and this fund is deposited at the center of the rust layer. A method for rolling out a hollow piece, which is characterized in that the core metal is placed in a section and then cast with a base metal latent steel, and the core metal is removed after the core metal ingot is formed into a predetermined shape.