US3892271A - Mould for making an article with a branch pipe by the electroslag remelting process - Google Patents

Abstract

A mould for making an article with a branch pipe by the electroslag remelting process comprises in combination parts to form the body and the branch pipe of the article, respectively, whose walls are provided with passages for a cooling agent. A pipe connection to supply the cooling agent to a passage provided in the wall of a part to form the branch pipe of the article, is disposed in the area adjoining the part to form the article body, wherein a consumable electrode is located. A pipe connection to withdraw the cooling agent from the pasage provided in the wall of a part forming the branch pipe, is disposed at the end of the part, which is remote from the electrode.

Description

Medovar et al. 1 July 1, 1975 [5 MOULD FOR MAKING AN ARTICLE WITH [51] Int. Cl 822d 27/02 A BRANCH PIPE BY THE ELECTROSLAG [58] Field of Search 164/52, 126, 128, 252,

REMELTING PROCESS Inventors: Boris lzrailevich Medovar, Bulvar Lesi Ukrainki, 2, kv. 8; Iiya Iosifovich Kumysh, Vozdukhoflotsky prospekt, 42, kv. 51; Georgy Alexandrovich Boiko, ulitsa Vladimiro Lybedskaya, l6, kv. 106, all of Kiev; Volf ludovich Rabinovich, ulitsa Gagarina 74, kv. 27, Chekhov Moskovskoi oblasti; Alexandr Ivanovich Sapozhnikov, ulitsa Mosfilmovskaya 17/25, kv. 63, Moscow; Georgy Sergeevich Marinsky, ulitsa Tatarskaya, l, kv. 9, Kiev; Jury Nikolaevich Kriger, ulitsa Oktyabrskaya, 38, kv. 59, Chekhov Moskovskoi oblasti, all of U.S.S.R.

Filed: Mar. 6, 1973 Appl. No.: 338,570

Foreign Application Priority Data Mar. 7, 1972 U.S.S.R 1754963 US. Cl 164/252; 164/348 [56] References Cited UNITED STATES PATENTS 2,388,974 11/1945 Hopkins 164/52 3,598,175 8/1971 Olsson 249/81 X Primary Examiner-Francis S. Husar Assistant Examiner-John E. Roethel Attorney, Agent, or Firm-Holman & Stern [5 7] ABSTRACT A mould for making an article with a branch pipe by the electroslag remelting process comprises in combination parts to form the body and the branch pipe of the article, respectively, whose walls are provided with passages for a cooling agent. A pipe connection to supply the cooling agent to a passage provided in the wall of a part to form the branch pipe of the article, is disposed in the area adjoining the part to form the article body, wherein a consumable electrode is located. A pipe connection to withdraw the cooling agent from the pasage provided in the wall of a part forming the branch pipe, is disposed at the end of the part, which is remote from the electrode.

3 Claims, 3 Drawing Figures MOULD FOR MAKING AN ARTICLE WITH A BRANCH PIPE BY THE ELECTROSLAG REMELTING PROCESS BACKGROUND OF THE INVENTION The present invention relates to a mould employed in an electroslag remelting process to make articles having branch pipes, for instance. bodies of high-pressure vessels and closing fittings or valves.

Such power engineering fittings are growing in demand because of a high growth rate of the power engineering, putting into operation of a great number of large-size power-engineering units, and because of a necessity to improve the performance of the powerengineering equipment and to curtail its cost.

A mould used in the electroslag remelting process for making articles having a branch pipe is known in the prior art, the mould comprising in combination parts to form the body and the branch pipe of an article, respectively; the parts are provided with walls having passages complete with pipe connections to effect the supply and withdrawal of a cooling agent flowing through the passage upwardly in the direction of an ingot being built up (cf. the book entitled Special Electric Metallurgy" (in Russian), USSR, published by Naukova dumka", reports of the International Symposium on Special Electric Metallurgy, Kiev, June 1972, Part 1, pages 173-174, FIGS. 1 and 2).

This mould enables one either to make the body simultaneously with the branch pipe or to fuse in the course of the electroslag remelting process to the former prefabricated cast or forged branch pipe stock.

However, only branch pipes 100 to l50 mm long can be made simultaneously with the body in such moulds. Yet in practice, when assembling the articles with branch pipes, it is desirable to employ the pieces having elongated branch pipes.

Attempts were made to manufacture an article having an elongated branch pipe by extending the part of the mould intended to form the branch pipe. Those at tempts did not produce favorable results since the surface of such a branch pipe exhibited defects resembling to corrugations.

These defects reduce the constructive strength of the branch pipe; that is why the branch pipes will have to be made thickened with the subsequent removal of the portions exhibiting those defects. The removal of the defects from the surface of those branch pipes by mechanical means leads to metal losses, so as to the use of additional epuipment, and waste of labor. The formation of the aforementioned defects results from the fact that in the mould of the prior-art design the supply and withdrawal of the cooling agent to and from the passages provided in the walls of the parts forming the branch pipe of the article is embodied without taking into account the temperature gradient in the molten slag and metal baths along the branch pipe to be formed.

Moreover, the part of the mould forming the branch pipe of the article, is embodied with the walls of the same thickness along the entire length of the branch pipe, in which there is provided a continuous annular gap or passage providing for the uniform withdrawal of heat throughout the entire length of the branch pipe to be formed, while the portion of this branch pipe adjoining the melting zone of a consumable electrode (or heat-evolution zone) receives a greater amount of heat than the portion of the branch pipe, which is remote from the consumable electrode. That is why the temperature of the baths of molten metal and slag lowers in the direction from the consumable electrode heat source to the free end of the branch pipe. Consequently, to improve the solidification conditions of the article branch pipe requires a non-uniform withdrawal of heat; namely, a greater amount of heat will have to be withdrawn within the heat-evolution zone, and a smaller amount of heat, within the portion of the branch pipe which is remote thereof.

The non-observance of these conditions is likely to create difficulties interfering with the manufacture of the branch pipes of a specified length having a goodquality surface.

SUMMARY OF THE INVENTION The primary object of the present invention is to provide a mould to be used in the electroslag remelting process for making an article with a branch pipe, for instance bodies of vessels or closing fittings, such as valves, dampers, shutters, etc., which would enable a branch pipe of a specified length to be cast.

Another, not less important, object of the invention is to improve the quality of the branch pipe surface throughout its length by obviating the formation of defects like corrugations on the surface thereof.

A still further object of the invention is to reduce the consumption of metal as may be caused by eliminating the defects on the branch pipe surface through mechanical treatment, and to dispense with the labor expenses involved therein.

While a preferred embodiment of the invention will be described hereinbelow, it will be understood that one skilled in the art may make various modifications in the mould without departing from the spirit of the invention and the scope of the appended claims.

These and other objects of the invention have been accomplished by the provision of a mould to be employed in the electroslag remelting process for making an article with a branch pipe, which comprises in combination parts to form the body and the branch pipe of the article, respectively, in whose walls there are provided passages complete with pipe connections for the supply and withdrawal of a cooling agent, in which, in accordance with the invention, the pipe connection to supply the cooling agent to the passages in the part forming the branch pipe of the article, is disposed within its area adjacent to the part forming the article body within a zone wherein a consumable electrode is located, whereas the pipe connection serving to withdraw the cooling agent from the passages, is disposed at the remote end of the part forming the branch pipe of the article.

Such a design of the mould part forming the branch pipe of the article, v creates a directed flow of the cooling agent from the portions of the slag and metal baths having a higher temperature to their portions having a lower temperature. Under these conditions, the more remote portions of the branch pipe will be cooled by the cooling agent raised at a higher temperature as compared with the portions adjacent to the heatevolution zone.

It would be advisable to make the mould in such a manner that the walls of its part forming the branch pipe of the article will grow thicker in the direction of the remote end of that part.

This will allow an increase in the temperature of the portions of the slag and metal baths that are disposed at the remote end of the branch pipe.

The mould part forming the branch pipe of the article may be provided with a passage following a helical line whose pitch progressively increases in the direction of the remote end of that part.

This will allow a reduction in the amount of heat to be withdrawn from the portions of the slag and metal baths disposed at the free end of the branch pipe.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described further in detail and by way of example with reference to the accompanying drawings, in which:

FIG. I is a view of the mould according to the present invention in section along the longitudinal axis of the parts forming the body and the branch pipe of an article to be made by the electroslag remelting process;

FIG. 2 is a cross-sectional view along the line II-ll of FIG. I; and

FIG. 3 shows the mould complete with a part to form the branch pipe, in whose walls there is provided a helical passage having a variable pitch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1 and 2, the mould suitable for use in the electroslag remelting process for making an article having a branch pipe comprises in combination parts 1 and 2 to form the body and the branch pipe of the article, respectively. The part 2 forming the branch pipe of the article has in its walls passages 3 for a cooling agent, the passages being interconnected through collectors 4 and 5. A pipe connection 6 is intended for supplying the cooling agent to the collector 4 and passages 3, and is disposed within an area adjacent to the part 1 forming the body of the article, near the zone wherein a consumable electrode 7 is located. A pipe connection 8 is intended for the withdrawal of the cooling agent from the collector 5, and is disposed at the remote free end of the part 2 forming the branch pipe of the article. The consumable electrode 7 is located in a gap between the mould part 1 forming the article body, and a core 9 serving to form the hollow of the article. The consumable electrode 7 is immersed into a bath 10 of molten slag, below which there are disposed a bath 11 of molten metal and solidified metal 12 of the article being made. The part 2 forming the branch pipe of the article has its walls 13 embodied such as to grow thicker in cross section in the direction of the free end of the branch pipe ('6, 8

In another embodiment of the part 2 forming the branch pipe of the article, as shown in FIG. 3, a passage 14 for the cooling agent is made in the form of a helical line whose pitch progressively increases in the direction of the free end of the branch pipe.

The mould of the invention operates in the following manner. A batch of molten slag is poured into a gap available between the core 9 (FIG. 1) and the mould part I forming the body of the article being made. As

the article is built up, the slag bath and the metal 1511mm rise and fill up the hollow provided in the A 'mould 'part' Ziorrning the branch pipe of the article being made. The cooling agent arrives in this part 2 through the inlet pipe connection 6 and the collector 4 to the passages 3, then to the collector 5, and flows out from the pipe connection 8.

The cooling agent flows in a similar manner through n the helical passage 14 (FIG. 3) from the pipe connections 6 to the pipe connection 8.

In both cases the cooling agent having a lower temperature first of all cools down the portions of the branch pipe that are disposed nearer to the zone of 15 melting the consumable electrode 7 and that are exposed to a more intense heating. Thereafter, the cooling agent having been preheated on the aforesaid portions, is supplied to the portions that are more remote from the consumable electrode 7 and are raised to a temperature lower than that of the molten metal and slag. The cooling agent absorbs the heat from those portions less intensely, and the portions of the metal and slag baths found therein will not be overcooled, which will contribute to equalizing the temperature of metal solidifying into the branch pipe throughout its length.

As it has been proved by testing, the described mould is suitable to make by the electroslag remelting process a good quality article with a branch pipe about 400 mm long.

We claim:

1. A mould to be used in an electroslag remelting process for making an article with a branch pipe, which comprises in combination: a first part having walls to form a body of the article; a second part having walls to form the branch pipe of the article and having a portion thereof disposed adjacent to said first part forming the body of the article; passages for a cooling agent being disposed in said walls of said first and second 40 parts forming the body and branch pipe of the article; a first pipe connection to supply the cooling agent into said passages disposed in said walls of said second part forming the branch pipe of the article, the pipe connection being disposed within an area adjacent to said first part forming the body of the article in a zone wherein a consumable electrode is located; and a second pipe connection to withdraw the cooling agent from said passages disposed in said walls of said second part forming the branch pipe said second pipe connection being further disposed at the remote end thereof.

2. A mould as of claim 1, wherein said second part forming the branch pipe of the article has its walls made to become thicker in cross section in the direction of the remote end of said second part.

3. A mould as of claim 1, wherein said second part forming the branch pipe of the article is provided with a passage made as a helix having a pitch which increases in the direction of the remote end of said second part. 60 I! l l l

Claims (3)

1. A mould to be used in an electroslag remelting process for making an article with a branch pipe, which comprises in combination: a first part having walls to form a body of the article; a second part having walls to form the branch pipe of the article and having a portion thereof disposed adjacent to said first part forming the body of the article; passages for a cooling agent being disposed in said walls of said first and second parts forming the body and branch pipe of the article; a first pipe connection to supply the cooling agent into said passages disposed in said walls of said second part forming the branch pipe of the article, the pipe connection being disposed within an area adjacent to said first part forming the body of the article in a zone wherein a consumable electrode is located; and a second pipe connection to withdraw the cooling agent from said passages disposed in said walls of said second part forming the branch pipe said second pipe connection being further disposed at the remote end thereof.

2. A mould as of claim 1, wherein said second part forming the branch pipe of the article has its walls made to become thicker in cross section in the direction of the remote end of said second part.

3. A mould as of claim 1, wherein said second part forming the branch pipe of the article is provided with a passage made as a helix having a pitch which increases in the direction of the remote end of said second part.

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