JPS5837058B2 - Manufacturing method of mold casting material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to eliminate defects that occur near the quenched surface of the mold in the production of cast products using metal molds, particularly solid cast materials that are quenched by the mold, thereby producing healthier cast products. This invention relates to something that can be reliably and easily obtained while improving production efficiency.

Including cast steel and cast iron rolls such as rolling rolls, solid castings made of iron and non-ferrous metal materials in relatively simple shapes,
As is well known, the mold quenching method is widely used in the casting production of rolled and forged materials. There are also problems to be solved in terms of the large number of man-hours required in the casting work.

To explain one typical example, Fig. 1 shows a general die casting method for a single solid roll. It is a vertical mold consisting of a mold 11 and upper and lower journal molds 12 and 13 made of a sand mold and a metal casting flask.
An injection pipe 15 is attached to the casting pipe 4, and the molten metal injected from the injection pipe 15 enters the mold through the sprue weir 14 by pouring method to perform casting.

At this time, the sprue weir 14 is installed in the tangential direction of the lower journal mold 13 so that the molten metal rotates upward in the mold and reaches a rotational speed of gravity ratio GA 6.3 to 6 at the inner diameter of the mold body. In this case, if the casting speed of the molten metal, the effective height of the sprue, and the cross-sectional area of the sprue are not appropriate, air entrainment, slag, etc. will occur on the surface of the roll body. Each time a book is cast, it is necessary to mold a sand mold in the lower journal mold 13 and mold the injection pipe 15, which requires a considerable number of preparation steps, and also requires the setting and dismantling of the mold for each casting. The total number of man-hours involved is large, and since it is a bottom pouring method, it is also disadvantageous that the temperature distribution during casting into a mold does not emphasize directional solidification in which the upper part finally solidifies.

Various attempts have been made to eliminate the need for injection pipes in the pouring method, including electromagnetic induction rotation, but the most effective, effective, and easy method is to use a vertical centrifugal casting machine. This seems to be the most likely option.

However, even when using a vertical centrifugal casting machine, the following problems still remain.

In other words, productivity is low due to the difficulty of mass production using the same casting machine due to the mold fixing method, etc., and in the case of long products (rolls are generally long because they have both journal parts), the vertical centrifugal method It is difficult to maintain balance, and extremely high precision is required in the mass production balance and rotation method of the mold, making it impossible to achieve production volumes that are considered industrially successful, such as the production of more than a few pieces per day using the same casting machine. be.

The present invention solves each of the above problems in the prior art,
Utilizing the characteristics of using a conventional vertical centrifugal casting machine, the weight balance of the mold is similar to that of a conventional horizontal centrifugal casting machine, and the man-hours for mold making and assembly are reduced compared to the pour-in-place casting method. This enables the industrial mass production of sound solid casting materials while preventing casting defects near the quenched surface of the mold. When manufacturing, the angle of inclination is 40°~
The mold was set in an inclined rotary casting machine set to 600,
The molten metal is poured from the upper part of the mold using a transfer gutter, and at the same time or immediately after the pouring, the mold is rotated at the inner diameter of the body mold so that the rotation speed becomes a gravity ratio GA 3 to 10. The point is that I tried to do it.

The present invention will be described in detail below with reference to the illustrated embodiments. Figure 2 shows an explanatory view of the casting apparatus used in the method of the present invention, and is an example of a solid roll as the target casting material.
Reference numeral 1 denotes a metal mold used in the present invention, and the mold 1 has a body mold part 1a integrally molded therein, and journal molds 2 and 3 are removably housed at both ends in the axial direction. The molds 2 and 3 shown in the figure are sand molds and flasks.

In the present invention, this metal mold 1 is set in an inclined centrifugal casting machine in which the center line O-O is inclined at an angle α of 400 to 600 with respect to the horizontal floor, and in the illustrated example, the angle α is 45°.
The journal mold 3 side of the mold 1 and the upper driving roller 5 and the lower driving roller 6 arranged under the axis parallel to the center line OO of the inclination angle,
The peripheral side of the mold 1 is set so that it can be rotated or stopped.

Each of the rollers 5 and 6 is equipped with a drive shaft 5a and 6a, and is arranged in a three-point arrangement, and is rotated using a motor or other prime mover 7 to provide the required amount of rotation to the entire metal mold 1. It is provided so as to impart rotation (see figure ■).

In this way, the target molten metal is moved into the metal mold 1 set in an inclined position from the journal mold 2 side on the upper side of the inclined position by the movable gutter 8 which is movable along the center line O-O. The casting of the present invention is carried out in the following manner using such inclined centrifugal casting means.

That is, as shown in the second figure, a metal mold 1 is set on a casting machine in an inclined position of 40° to 60°, and a desired molten metal is poured from above the mold 1 using a movable gutter 8. , the rotation speed at the inner diameter of the mold of the body is the gravity ratio G / 16:3 ~
Continue pouring the molten metal while rotating the mold 1 so that the angle of rotation is 10. After casting is complete, stop the rotation of the mold 1, and stand the mold 1 vertically until the molten metal stops rotating. , and then moved to a predetermined position to complete coagulation.

At this time, instead of rotating while pouring, the mold may be rotated at the above-mentioned rotational speed for a certain period of time immediately upon completion of pouring, and in the case of steel and non-ferrous metal materials, this method may be used. There is also.

In the method of the present invention, the rotation speed of the mold is set to a weight ratio OA of 3 to 10 at the inner diameter of the body mold, because when rotating with 2 G scraps, even if the surface of the body of the cast product is turned for 10 minutes, Although there were gas holes, GA4, 5, 6,
This is because it was confirmed that there were no gas holes at all when the surface of the body of the cast product was turned at 5 degrees.
Also, the range of 3 to 10 is because if it is less than 3, gas holes may exist, and if it is more than 10, it may take time to stop the rotation, and the slip layer on the surface of the body may become thick.
This is because the amount of turning increases, safety considerations increase as the number of rotations increases, and there is no point in rotating at higher speeds.

In addition, in the present invention, the tilt angle of the tilted rotary casting machine is set to 40
The reason why the angle was set at 0 to 60 degrees was because there is a drawback that if the angle is below 40 degrees, it takes time for the slag and other debris that gathers in the center to rise.
Since the hot water level at the top of mold 1 is too slanted,
This is because it is necessary to make it larger than 00, and the reason why it is set below 600 is because of the relationship between the vibration generated in the mold and the rotation speed.
This is an upper limit based on experience.

A solid roll is shown as an example of a cast product in Fig. 2, but in the illustrated mold 1, the lower journal mold 3 was eliminated and the upper journal mold was used as a heat generating sleeve to cast tool steel material. An excellent ingot was obtained, and even if the ingot collapsed, by casting a solid metal material by the method of the present invention, a sound cast product with no defects near the surface of the body due to rapid cooling of the mold was obtained. be.

'Also, when mass-producing the same product, according to the method of the present invention, even if the upper and lower journal molds 2 and 3 in the illustrated example are sand molds, they can be used repeatedly 4 to 5 times. If the three parts are used as a mold and a refractory layer with a thickness of about 10 mm is applied to the inner surface of the mold, it can be used repeatedly many times, and industrial mass production can be achieved. It is also significantly superior in terms of increased efficiency and improved productivity.

Next, specific examples using the method of the present invention will be shown.

Example 1 Using an inclined rotary casting machine fixedly installed at an inclination angle of 45°, ductile cast iron rolls ( body 550$ x 1200l), Glen roll (body 380, 800l), Adamite roll (body 55
0 x 1400 l) were cast respectively.

At this time, the body mold part 1a of the mold 1 is made with an appropriate number of through gas holes. 3
A 11!71l graphite coating mold is applied*, and the upper and lower journal molds 2 and 3 are set therein, and the target molten metal is poured while rotating at a rotation speed corresponding to the weight ratio GA6 at the inner diameter of the body mold. Each was poured and cast.

In each casting roll obtained in this way, 5 mm for the ductile roll, 4 mrrt for the Glenlaw Nore,
At a body turning distance of 15 mm using the Adamite roll, an excellent solid roll body was obtained with no gas holes or foreign matter entrapped.

Example 2 Using mold 1 in Figure 2, the lower journal mold 3 part was removed and the upper journal mold 2 part was reorganized into a heat generating sleeve, and the same chemical composition as in Example 1 was used as shown in Table 1. Tool steel material ingot (60
0〆×800 l) was cast in the same manner, and an excellent ingot was similarly obtained.

The present invention is as follows, and includes cast steel such as rolling rolls, cast iron rolls, relatively simple-shaped ferrous and non-ferrous solid castings, and production by casting means of similarly solid rolling and forging materials. In this regard, compared to the conventional techniques such as bottom pouring casting method into a vertical mold and vertical centrifugal casting method, the generation of defects due to air entrainment and slag bite near the quenching surface of the mold is eliminated. It is excellent in obtaining sounder solid castings, eliminates the need for high accuracy in mold weight balance and rotation method in vertical centrifugal casting machines, and further reduces molding and assembly man-hours.
The model centrifugal casting machine is excellent in that it can easily increase the daily production of several dozen pieces (20 to 30 pieces) by just balancing the mold weight using the same casting machine. This method does not require sophisticated technology and greatly contributes to the ease of industrial production of rapidly cooled solid casting materials for molds.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of a conventional solid roll body casting means of the pour-down method, and FIG. 2 is an explanatory diagram of an example of casting equipment as an embodiment of the method of the present invention. 1...Mold mold, 1a...Body mold part,
2, 3...Journal mold part, 4...
Cradle, 5.6... Drive roller, 7...
- Prime mover, 8...Movable gutter.

Claims (1)

[Claims] 1. Mold When producing rapidly cooled metal solid materials, a metal mold is set in an inclined rotary casting machine with an inclination angle of 40° to 60°, and the molten metal is transferred from the top of the mold using a gutter. The molten metal is poured, and at the same time or immediately after the molten metal pouring, the rotation speed at the inner diameter of the body mold in the mold reaches a gravity ratio of G43 to 10.
A method for producing a mold casting material, which is characterized by rotating the material so that