JPS60244462A - Riser heating method - Google Patents

Abstract

PURPOSE:To heat a riser with good thermal efficiency without spattering or scattering of a molten metal and slag by conducting electricity to the slag via an electrode inserted into the slag and transmitting the electric resistance heat of the slag to the molten metal. CONSTITUTION:The slag 14 and heat reserving material 12 are disposed in the upper part of the molten metal 13 as the riser put into the mold hole 11a of a riser wall 10. The electrode 15 contacting with the slag 14 through the material 12 is provided. Electricity is conducted via the electrode 15 to the slag 14 and the molten metal 13 which is the riser is heated by the electric resistance heat of the slag 14. The riser is thus electrically stably heated wiht the good thermal efficiency without spattering, scattering, etc. of the molten metal 13 and the slag 14, generation of the radiation heat of an arc and disturbance of the molten metal 13 surface.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method of heating a riser.

BACKGROUND OF THE INVENTION In the production of conventional technology castings, a riser is essential to compensate for the solidification shrinkage of molten metal. By heating this riser, the effect of the riser can be enhanced and the product yield of cast products can be increased.

A conventional heating method for a riser is a heating method using an arc.

Interval point to be solved by the invention This heating method has the following problems because an arc 3 is generated between the electrode 1 and the molten metal 2 as shown in FIG.

(1) Sputtering, molten metal 2. Slag 4 scatters.

(2) The heat loss as radiant heat of the arc 3 is large.

In other words, thermal efficiency is poor.

(3) The surface of the molten metal is disturbed by the arc force and is electrically unstable. For this reason, it is often difficult to prevent radiant heat loss from the surface of the molten metal.

(4) The area to be heated is narrow, and the bath molten metal 2 of the feeder wall 5
(5) The carbon from the pole 1 is often transferred to the molten metal 2, which adversely affects the components of the product.

(6) Large reactive power (power factor approximately 0.7).

The present invention was developed in view of the above circumstances, and its objectives are that, compared to conventional heating methods using arcs, there is no sputtering, no scattering of bath molten metal or slag, and radiant heat of the arc. There is no generation of heat and thermal efficiency is improved.

The surface of the molten metal is not disturbed by the arc force, making it electrically stable, the heated area is wider, and the feeder effect can be improved, and the transfer of carbon from the electrode to the molten metal is reduced, making the product more stable. It is an object of the present invention to provide a riser heating method that does not adversely affect the components of the water and can use only a small amount of reactive power.

Means and operation for solving the problems In the present invention, electricity is applied to the slag 14 through the electrode 15, and the feeder is heated by the electric resistance heat of the slag I4.

Example The present invention will be explained below with reference to FIG.

10 is a feeder wall, a heat insulating material 12 is provided above a mold hole 11 of the feeder wall 10, and a molten metal 13 as a feeder and slag I4 are placed in the mold hole 11. υ, insulation material 12
An electrode 15 made of carbon dioxide passes through the electrode 15.
is in contact with the slag 14.

The molten metal 13, which is the feeder, is heated by applying electricity to the electrode 15 and using the electrical resistance heat of the slag 14.

That is, the feeder is heated by the principle of electroslag bath welding.

The principle of electroslag bath welding is not the heat of the arc, but the resistance heat generation (Joule heat) of the current flowing through the wire and molten slag.
At the start of welding, an arc is generated momentarily within a single grain of flux, but once enough flux has melted and a slag bath is formed, the arc disappears.

The wire and the groove surface become melted mainly due to the resistive heat of the bath-melting slag.

Effects of the Invention The present invention is as described above, and the slag 14 is energized via the electric wire 15, and the feeder is heated by the electrical resistance heat of the slag 14. Therefore, the conventional heating method using an arc can be avoided. Compared to 13., there is no sputtering and there is no sputtering. slag 1
4, there is no scattering, there is no generation of radiant heat from the arc, which improves thermal efficiency, there is no disturbance of the molten metal surface due to arc force, making it electrically stable, and the heating area is wide and the feeder effect can be improved. In addition, the transfer of carbon from the electrode 15 to the molten metal is small, and the components of the product are not adversely affected, and the reactive power is reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional feeder heating method, and FIG. 2 is an explanatory diagram of a feeder heating method according to the present invention. I4 is slag, 15 is %, pole. Applicant Komatsu Ltd. Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 1 Figure 2

Claims (1)

[Claims] This method of heating a feeder is characterized in that electricity is applied to the slag 14 via an electrode 15, and the feeder is heated by the electrical resistance heat of the slag 14.