JP2009190086A - Process for casting steel grade which cannot be cast by evaporative pattern depressurization casting process with use of same process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for casting some steel grades which can not be cast by an evaporative pattern depressurization casting process because foam resin for pattern assembly is changed into a lot of gases at the time of evaporation. <P>SOLUTION: Foam resin made of 100% acrylic and having a minute carbon content is used to make a pattern part 5. A casting frame 1 has structurally a wholly hollow concave with innumerable holes 2 of 62 mm opened over the entire surface on the casting chamber side and a hole 3 of 80 mm opened on the outside flank, while the total holes on the casting chamber side are covered one over the other with each metal mesh 4A, 4B and 4C with different eyes, and the hole on the outside of the casting frame and a receiver tank connected to a depressurization device are connected with a heat-resistant hose. Casting is performed by working the depressurization device. This process enables gases filled in the casting chamber to be efficiently removed from the holes opened on the whole surface in the casting chamber side to a vacant part of the concave form. Incidentally, the metal meshes are used to prevent sand from flowing therethrough. As a result of performing casting of a stainless steel SCS13 grade with this process, steel quality is excellent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

Detailed Description of the Invention

Technical analysis belonging to the invention

In the present invention, 100% acrylic foamable resin is used for a model member made of stainless steel having a carbon content of 0.08% or less by the disappearance model vacuum casting method.
Although this resin component changes into a large amount of gas at the festival that disappears due to the heat of molten metal, the amount of carbon is very small.
Note that a large amount of gas in the casting chamber is quickly moved out of the casting chamber by the operation of the decompression device through the hole (2) formed in the entire inner flask-like shape of the concave casting frame (1) and the concave cavity (9). It is possible to remove it.

In the conventional disappearance model decompression casting method, it is customary to use a mixture of two types of foaming resins such as polystyrene, polymethyl methacrylate or methacryl for a casting model member. In this method, the gas generated at the festival where the model disappears is removed from a part of the casting chamber.
This method is mainly used for casting iron, cast steel and aluminum.

Problems to be solved by the invention

This vanishing model vacuum casting method has the following drawbacks.
In this method, a foamable resin is used as a model member, but when the resin disappears due to molten metal heat, it changes into a large amount of gas and stays in the casting chamber.
(1) Carbon in the gasified resin component fuses with the same component of the molten metal and affects the steel quality of the casting.
(2) A part of the gasified resin component solidifies on the wall surface of the cavity where the model has disappeared and affects the shape of the casting.
Due to the above problems, this is a factor that is not suitable for casting of steel grades such as Japanese Industrial Standards, Steel Grade Steel Quality Standards, Stainless Steels with Carbon Content of 0.08% or Less, SCS13, SCS14, and the like.

Means to be Solved by the Invention

The present invention has been made to solve the above-described drawbacks.
A 100% acrylic foamable resin with a small amount of carbon is used for the casting model member. For casting, a casting frame (1) shown in FIG. 1 is used.
The structure of the casting frame (1) is a concave shape with a hollow that combines a box shape on the outside and a flask shape on the inside, 61 mm holes (2) innumerable holes on the casting chamber side flask shape, and on the outer side surface. One 80mm hole (3) is opened.
When casting is performed, the entire hole (2) is covered with metal meshes with different eyes, mesh number 30 (4A), 100 (4B), and 200 (4C). And it is the method of casting by operating the pressure reduction pump (10) by the structure which connected the receiver tank (11) connected with the pressure reduction pump (10), and the hole (3) with the heat-resistant hose (12).

Hereinafter, an embodiment in which the steel type stainless steel / steel number SCS13 according to the present invention is implemented by the vanishing model reduced pressure casting method will be described.
A model (5) of a cube of 300 mm × 150 mm × 20 mm is produced by using a foamable resin of 100% acrylic as a model member for casting.
The model (5) was embedded in the sand (8) of the casting frame (1) installed on the vibration device (13), and the hot water inlet (6) and the hot water outlet from the side of the model (5) body. (7) is applied upwards, the vibration device (13) is operated, and the sand (8) is brought into close contact with the model (5). The stainless steel SCS13 is melted at 1650 degrees Celsius, and the receiver tank (11) The decompression rate is set to 350 HP, casting is performed by operating the decompression pump (10), and then decompression is continued for about 20 minutes to complete casting.

The invention's effect

In the present invention, the steel type stainless steel / steel quality number SCS13 is subjected to the disappearance model reduced pressure casting method, and the position A where the hot water inlet (6) of the cast product is cut and the position B where the hot water inlet (7) is cut are analyzed. As a result, the carbon content is as follows.
Position A 0.069 Position B 0.073
This conforms to the steel content standard of 0.08% carbon content of Japanese Industrial Standard / steel quality number SCS13, and the shape of the cast product is also good.
The other steels are shown in the attached sheet / analysis table.

Sectional drawing This figure represents the form and structure of the casting frame of the present invention in section. [Explanation of Symbols] Symbol 1 Casting frame 2 Hole 3 Hole 4A Metal mesh 30th 4B Metal mesh 100th 4C Metal mesh 200th 5 Model 6 Hot water inlet 7 Hot water inlet 8 Sand sand 9 Cavity group FIG. 2 is a front view showing the configuration of an apparatus related to the disappearance model vacuum casting method. [Explanation of Symbols] Symbol 1 Casting frame 10 Pressure reducing pump 11 Receiver tank 12 Heat-resistant hose 13 Vibration device

Claims (2)

In order to perform Japanese Industrial Standards, Steel Standards, Stainless Steels with a carbon content of 0.08 or less, SCS13, SCS14, etc., by using the disappearance model vacuum casting method, 100% acrylic foamable resin is used on the disappearance model part. This method is used. The casting frame (1) used in claim 1 is a concave shape in which the whole is a hollow shape in which two layers of a box shape on the outside and a flask shape on the inside are combined, and an infinite number of 64 mm holes (2) are opened on the front surface of the inner flask shape It is related to the structure of the casting frame (1) in which one 80 mm hole (3) is formed on the outer side surface.

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