JPH0747489A - Electric welding rod of gray cast iron - Google Patents

Abstract

PURPOSE:To manufacture an electric welding rod of gray cast iron and to execute electric welding of the gray cast iron. CONSTITUTION:A core bar 1 is manufactured by adding a scrap of copper and a scrap of a silicon steel plate to gray cast iron and casting it by a molten metal of a dissolved alloy. Subsequently, covering 2 is manufactured by pulverizing and mixing an instantaneous inoculant of about 60g and a degassing inoculant of about 40g, respectively against limestone of 1kg and the welding rod is manufactured. Thickness of the covering 2 is set to 1mm. When the covering 2 becomes too thick, the core bar 1 is melted first, therefore, the covering remains and continuous welding becomes impossible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention enables electric welding of gray cast iron, which has hitherto been impossible.

[0002]

2. Description of the Related Art Conventionally, electrical welding of gray cast iron has been impossible. Since the casting is thick, it cannot be gas welded.
Therefore, if a defective product appeared at the casting stage, it had to be melted again. If it is a large cast product, it will cause a great deal of damage to make it a defective product, so if nickel welding causes a sink mark on the defaced surface, it is filled with solder and nickel.

[0003]

When electric welding of gray cast iron is made possible by the present invention, what has been a defective product in the past has become a good product due to this welding, and
It is economically effective.

[0004]

[Means for Solving the Problems] Gray cast iron has hitherto been impossible to be electrically welded. However, the use of the gray cast iron welding rod of the present invention enables electric welding. The manufacturing method of this electric welding rod is as follows: As core metal of the welding rod, cast iron is cast with copper scrap, and scraps of silicon steel plate are added to the molten alloy to make a casting.
A welding rod is manufactured using 0 g and about 40 g of the degassing inoculant, which are made into fine powder and mixed. Next, regarding the method of welding, to prevent the welding rod from burning into the holder and melting, use a holder made entirely of copper. Among the resistance machines currently on the market, those that can be used as electric welding machines are direct current electric welding machines and direct current gouging resistance machines. When electric welding is performed using the resistance machine with the welding rod of gray cast iron according to the present invention, electric welding which has been impossible in the past can be performed. Welding of castings must be done in a short time because the material will change and carbonize if done over time.

[0005]

[Function] The core metal of the electric welding rod is manufactured by casting in molten alloy water by adding copper scraps and silicon steel scraps to gray cast iron. And about 60 kg of instant inoculum for 1 kg of limestone in the coating
and a degassing inoculant of about 40 g are made into fine powder and mixed, and a welding rod is manufactured. Here, limestone is used to remove impurities generated during electric welding and to help the digging and flow of the molten metal for stable electric welding, and the instant inoculant is used to stabilize the components of the molten metal. Degassing inoculants are used to prevent pinholes and other defects. There are 1 to 6 types of gray cast iron, but the gray cast iron that serves as the core metal uses the same co-material as the base material for electric welding. Then, when the gray cast iron as the core metal is one to three types, the copper content to be added is large and the silicon steel plate waste is small. That is, about 0.2 ~
0.3%, about 0.1 to 0.2% of scrap of silicon steel plate are added.
Copper scraps of about 4 to 6 kinds are about 0.1 to 0.2%, and steel plate scraps are about 0.2 to 0.3%. Copper is necessary for preventing the generation of cracks and bubbles due to electric welding due to the brittleness of gray cast iron, and for the base metal and the welded portion to intersect well during electric welding to provide strong strength and elasticity. Silicon steel sheet waste is added to prevent the iron from carbonizing in a short time due to the high temperature during electrical welding of gray cast iron.

[0006]

The present invention is very useful because it enables electric welding of gray cast iron, which has been impossible in the past, and allows defective products produced during or after casting to be used as good products.

[Brief description of drawings]

FIG. 1 is a plan view of a welding rod of the present invention.

FIG. 2 is a sectional view of the welding rod of the present invention.

[Explanation of symbols]

1 core metal (gray cast iron, copper, alloy of silicon steel plate) 2 coating (composed of limestone, instant inoculant, degassing inoculant)

Claims (1)

[Claims] 1. A method for producing an electric welding rod of gray cast iron. A core metal of a welding rod is produced by casting a molten cast iron with copper scrap and scrap of a silicon steel plate. Then, as a coating, a welding rod is manufactured by using a mixture of 1 kg of limestone with about 50 g of an instant inoculant and about 40 g of a degassing inoculant, which are made into fine powder. The thickness of the coating is 1 mm. If the coating becomes too thick, the core will melt first and the coating will remain, making continuous welding impossible.