Patent Publication Number: US-3875992-A

Title: Electroslag remelting plant

Description:
United States Patent 1191 Paton et a1.  
 ELECTROSLAG REMELTING PLANT [761 Inventors: Boris Evgenievich Paton, ulitsa Filed:  
  Kotsjubinskogo, 5; Boris lzrailevich Medovar, bulvar L. Ukrainki, 2. kv. 8; Lev Andreevich Shuruev, ulitsa Gagarina, 10/2, l v. 7; Georgy Alexandrovich Boiko, ulitsa Vladimiro-Lybedskaya, l6, kv. 106; Sergei Petrovich Egorov, ulitsa Nevskaya, 34, kv. 1, all of Kiev; Lev Vasilievich Popov, ulitsa Kharkovskaya, 2, kv. 21, Bryansk; Rudolf Solomonovich Dubinsky, ulitsa Politekhnicheskaya, 5, kv. 209, Kiev, all of U.S.S.R.  
 May 14, 1973 App]. No.: 360,027  
 U.S. Cl. 164/252 Int. Cl. 822d 27/02 Field of Search 164/52, 252  
 1 1 Apr. 8, 1975 156] References Cited UNITED STATES PATENTS 3,602 623 8/1971 Wooding 13/14 3.614.285 10/1971 Holzgrubcr et al. 13/14 3.693.699 9/1972 Holzgruber et al. 164/250 Primary Examiner-Francis S. Husar Assistant Examiner-John E. Roethel Attorney, Agent, or FirmHolman &amp; Stern [57] ABSTRACT An electroslag remelting plant is disclosed, said plant comprising masts. connected by a gantry, and crossarms travelling along the masts in parallel planes. The upper cross-arm is adapted for mounting an electrode holder with consumable electrodes and the lower one for a cooled mould, each cross-arm being made up of two parts either of which is a carriage moving independently along the mast.  
 8 Claims, 9 Drawing Figures PATENTEUAPR 1% .&#34;1875892 saw 1 0r 5 PATENTED 81% 3.875.992  
 saw 2 [1F 5 PATENTEDAPR 8 I975 sum 3 BF 5 ELECTROSLAG REMELTING PLANT BACKGROUND OF THE INVENTION The present invention relates generally to equipment for special electrometallurgy and more particularly it relates to plants for electroslag remelting of metal and the electroslag melting of metal ingots.  
  Electroslag remelting plants are known in the art comprising a single vertical mast and carriages travelling in mast guides. The upper carriage serves for tra versing an electrode and the lower one for shifting a mould. The furnaces using this arrangement are simple in design but they are unsuitable for producing heavy (more than 5 t. in weight) ingots. insofar as the mast featuring adequate rigidity would have very large crosssections.  
  The electroslag remelting plants with several masts are also well known. The use ofa plurality of the masts enables the construction of high-capacity plants (up to 200 t. and over), the masts of such plants being connected by a gantry and featuring thereby high rigidity with a relatively small sections. Usually in these furnaces electrode holders with consumable electrodes and cooled moulds are fastened to cross-arms located horizontally in parallel planes and furnished with drives adapted for their vertical traverse. In this case, the electrodes are electrically associated with a power supply source and the mould has a fixture for securing it to the cross-arm. However. the above-described furnaces are economically unpractical for melting ingots differing substantially in their mass. They are also unsuitable for melting shaped ingots, e.g. cranks for crank-shafts, insofar as with the modern techniques of melting such in gots the consumable electrodes are remelted not directly in a shaping mould but in a separate melting vessel from which molten metal overflows to the mould. In this case. the mould is stationary and the melting vessel traverses relative to the mould. The design of such a plant becomes much more sophisticated.  
 SUMMARY OF THE INVENTION The main object of the present invention is to provide an electroslag remelting plant which would allow melting ingots of a different weight ranging from I t. to 200 t. and over.  
  Another object of the invention is to provide an electroslag remelting plant featuring a substantially higher production rate as compared with the known plants of this type.  
  Still another object of the invention is to provide an electroslag remelting plant whose inherent design will be simpler as compared with the known plants of the same type.  
  Apart from the above-specified objects of the invention, a further object is the provision of an electroslag remelting plant which will permit sufficiently simple melting of shaped ingots.  
  These and other objects are achieved in an electroslag remelting plant comprising masts connected by a gantry and carrying cross-arms arranged horizontally in parallel planes and fitted with drives for their vertical traverse along the masts. with the upper cross-arm being adapted for securing an electrode holder with consumable electrodes associated electrically with a power supply source and the lower one for mounting a cooled mould with its fixtures fastening it to the crossarm, wherein. according to the invention. both crossarms are made up of two parts either of which is a carriage moving independently along the mast, and the electrode holders with the consumable electrodes and the moulds with their fixtures are set up respectively at the opposite ends of the upper and lower carriages, with one of the opposite ends of the carriages being located between the masts.  
  The above arrangement of the hereinproposed electroslag remelting plant enables the production of ingots of different weight and diversified shape by melting simultaneously several ingots.  
  Moreover. the proposed plant is much simpler in terms of its construction than the known plants of the same type.  
  Further, the invention is characterized by the fact that each lower carriage is fitted with current-carrying elements coupling the mould with the power supply source.  
  It is quite reasonable that each lower carriage be provided with a device for connecting the current-carrying elements to contact elements of the mould.  
  Each lower carriage can have enclosed spaces for feeding and discharging a coolant, the spaces being insulated from each other and in communication respectively with a delivery mains and a drain of the plant cooling system.  
  It is also expedient that the mould fixtures be made with a possibility of adjusting axial alignment of the mould with respect to the electrodes.  
  It proved also possible to construct the plant in such a way that the electrode holder will be furnished with sleeves insulated from the electrode holder and plant casing and provided with sockets for securing consum able non-electrified blanks.  
  In addition, the electrode holder may incorporate supporting elements affording the possibility ofdisplacing the electrodes relative to one another during their adjustment.  
  In the long run, it is expedient that the mould fixtures be electrically insulated from the plant casing.  
 BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood from a consideration of a detailed description of an exemplary embodiment thereof, when read in conjunction with the accompanying drawings. wherein:  
  FIG. 1 is a general view of the electroslag remelting plant according to the invention (longitudinal section);  
  FIG. 2 shows a general view of the plant according to the invention, with the removed gantry (cross-section FIG. 3 depicts unit III in FIG. 2; FIG. 4 is a view taken along the line lV-IV of FIG.  
  FIG. 5 presents the mould fixture according to the invention (longitudinal section);  
 FIG. 6 is a view taken along arrow VI in FIG. 1;  
 FIG. 7 shows unit VII in FIG. 1;  
 FIG. 8 is a view taken along arrow VIII in FIG. 7; and  
  FIG. 9 shows a general view of the plant. according to the invention, with a movable and stationary moulds (longitudinal section).  
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT There is proposed an electroslag remelting plant comprising masts I (FIGS. 1 and 2) connected by a gantry 2. The number of the masts depends on the number and weight of the ingots to be produced.  
  In the hereinbelowdescribed exemplary embodiment we shall proceed from an assumption that the plant comprises two masts.  
  The masts l are rectangular in crosssection and mount cross-arms 3 and 4 arranged horizontally in parallel planes and fitted with gear drives (FIG. 1 for their vertical traverse along the masts I. The cross-arms 3 and 4 will be further referred to as an upper and lower one in accordance with their arrangement.  
  Each crossarm 3 and 4 is made up of a carriage adapted to travel vertically along the mast l independently of the other.  
  The carriages of the upper cross-arm 3 will be denoted by item 5 and those of the lower cross-arm 4 will be denoted by numeral 6.  
  Each carriage 5 and 6 mounts two angle brackets designated respectively by numerals 7 and 8 and located at the opposite ends of the carriages 5 and 6 with one of the opposite ends of each carriage 5 or 6 being positioned between the masts I.  
  Each upper angle bracket 7 of the upper carriage 5 mounts an electrode holder 9 together with its fixture in which electrode holder are secured consumable electrodes 10 associated electrically with a power supply source 50 with the aid of current-carrying elements II. In the electrode holder 9 provision is made for sleeves I3 insulated from the electrode holder 9 by means of special bushes 12 (FIG. 3) with the sleeves being fitted with a socket 14 for fastening consumable non-electrified blanks 15.  
  The electrode holder 9 is fitted with supporting ele ments I6 (FIG. 4) set up in the electrode holder so as to allow their relative displacement with respect to each other to adjust the position of the electrodes 10 when setting-up the furnace, and with hold down elements I7 insulated from the electrode holder 9 by a plate 18.  
  The lower carriages 6 are adapted for securing moulds I9 (FIG. 5) or melting devices. To this end the angle brackets 8 are furnished with fixtures which may differ in design and in our example represent a shoe mounted in a slot 21 provided in the angle bracket 8 of the carriage 6. The upper surface of the shoe 20 is located obliquely to its base and mounts a shoe 22 whose surface of conjugation with the shoe 20 is inclined to the base at the same angle as that of the shoe 20. The upper surface of the shoe 22 is thereby parallel to guides provided in the slot 21. A screw 23 which is fixed to prevent its axial displacement in the shoe 20 is threaded and thus engaged with the shoe 22 so that when the screw 23 is in rotation the shoes 20 and 22 may shift with respect to each other. The lower shoe 20 is threaded and put on a guide screw 24. When the lat&#39; ter is rotating. the shoe 20 traverses along the slot 21. The shoe 22 is fitted with a vertical cylindrical pin 25 which enters a corresponding groove 26 of the mould 19. whose supports are provided with plates 27 which serve to insulate the casing of the mould 19 electrically from the carriage 6.  
  For supplying coolant into the mould 19, the body of the carriage 6 is fitted with closed spaces insulated from each other. The coolant is fed into the space 28 (FIG. 6) from a delivery main of the furnace cooling 5 system with the space 29 being connected to a system drain. The spaces 28 and 29 ofthe carriage 6 are connected by hoses 30 (FIG, 5) to corresponding spaces of the cooling system of the mould I9.  
  In order to supply working voltage to the mould I9, the lower carriage 6 is equipped with tubular watercooled bus bars 31 (FIG. 7) connected to the power supply source 50. The mould 19 is also furnished with current-carrying elements 32 (FIGS. 7, 8) mounted in clamps 33 adapted to couple the tubular bus bars 31 with the current-carrying elements 32 of the mould 19. To enable the displacement of the mould 19 the tubular bus bars 31 are so enclosed in a sleeve 34 with the help of a bush 35 (FIG. 7) as to allow their horizontal traverse in relation to the sleeve 34 along the axis of its opening and turning about the vertical axis of the sleeve 34 with respect to the body of the carriage 6.  
  An ingot is melted on the above-described plant in the following manner.  
  Consumable electrodes I0 are secured in electrode holders 9 and the mould 19 is mounted on an angle bracket 8 of a lower carriage 6. The mould I9 is brought in alignment with the electrodes 10 with the aid of its fixtures. To this alignment the screw 23 actuates shoes 20 and 22. Owing to an interaction of their oblique surfaces the shoe 22 performs a parallel motion in a vertical plane. This allows to achieve vertical arrangement of the axis of the mould 19. By rotating guide screws 24 on both angle brackets 8 the shoes 20 and 22 are displaced to provide similar clearances between the walls of the mould l9 and consumable electrodes II]. By traversing the carriage 6 the mould I9 is placed in its lower initial position.  
  With one of the known methods, eg by pouring molten slag from a ladle, a pool of molten slag is established in the mould l9 and working voltage is applied across the electrodes 10. As an ingot 36 (FIG. 9) is built-up, the mould 19 is carried upwards so as to keep the level of a metal pool at a constant height from the lower edge of the mould I9. Upon remelting the consumable electrode 10, the mould I9 is stopped and the slag is removed by using a known procedure. for instance. by pouring if off through a bottom gate of a known design. By shifting the mould l9 upwards. the ingot 36 is stripped to be rolled thereupon out of the working zone with the aid of a car 37.  
  The plant is suitable for melting two ingots simultaneously. For melting one heavy ingot (more than [0 t. in weight) use is made of both inner angle brackets 7 and 8 of the plant-carriages 5 and 6. Both the melting techniques and the sequence of adjusting operations do not differ from those disclosed hereinbefore. However, in this case the electrodes I0 are mounted on both upper carriages 5. A mould 38 (FIG. 9) may be either stationary, being on that occasion set up on a car 39 to be wheeled off, or a movable one, being then fastened to the carriage angle brackets, as it has been described above. The here-in-proposed plant affords the possibility of melting not only ingots of a simple and constant, to their height, section but shaped ingots as well.  
  The modern technique of melting shaped ingots envisages the remelting of consumable electrodes not di rectly in the mould 19 but in a melting vessel 41 having a common slag pool with a mould 40 shown in FIG. 1 by thin lines. In this case the melting vessel 40 is shifted in relation to the stationary mould 40, forming the ingot. For melting ingots by this method. the melting vessel 41 mating with one of its sides with the mould 40 is mounted on the angle brackets 8 of the lower carriage 6. Then consumable electrodes 42 are remelted in the melting vessel 41. Metal flows over its bottom into the space of the mould 40 where it solidifies. As the level of metal in the mould 40 rises, the melting vessel 41 is carried upwards.  
  Thus a single plant may be utilized for melting two ingots concurrently with the ingots differing seriously in their size and shape. It is suitable for melting largesize ingots both of a simple and intricate shape. The melting vessels can be installed on both sides of the mould insofar as the plant carriages are arranged one opposite another. Due to this the production rate can be doubled when melting shaped ingots.  
  The above-described plant enables a solution. and a very simple one, of the problem which constitutes the object of the present invention.  
 We claim:  
  1. An electroslag remelting plant comprising: masts; a gantry; cross-arms being disposed horizontally in parallel planes so that one of said cross-arms defines an upper one and another one of said cross-arms defines a lower one; said masts being connected by said gantry and carrying said cross-arms; each of the upper one and lower one said cross-arms being fitted with movable carriages; means for traversing independently said carriages along said masts; electrode holders; a power supply source; consumable electrodes set up in said electrode holders and associated electrically with said power supply source; fixtures of said electrode holders adapted for fastening them to the upper one of said Ill cross-arms; a cooled mould; fixtures of said cooled mould adapted for fastening them to the lower one of said cross-arms; two opposite ends of each of said upper and lower carriages; one of said two opposite ends of said upper and lower carriages being located between said masts; and said electrode holders with said fixtures and said moulds with said fixtures being mounted on both said opposite ends of respectively said upper and lower carriages.  
  2. A plant of claim 1 wherein each lower carriage is fitted with current-carrying elements connecting said mould to said power supply source.  
  3. A plant of claim 2 wherein each lower carriage is provided with a device for coupling said current carrying elements with contact elements of said mould.  
  4. A plant of claim 1 wherein each lower carriage is fitted with closed spaces for supplying and discharging coolant insulated from each other and communicating respectively with a delivery main and with a drain of the plant cooling system.  
  5. A plant of claim 1 wherein said fixtures of said mould include means for adjusting an axial alignment of said mould in relation to said electrodes.  
  6. A plant of claim 1 wherein said electrode holders are provided with sleeves for mounting consumable non-electrified blanks insulated from the electrodes and from the plant casing.  
  7. A plant of claim 1 wherein said electrode holders are furnished with supporting elements accommodated within said electrode holder and ensuring the possibility of adjusting relative displacement of the electrodes with respect to one another.  
 8. A plant of claim 5 wherein said fixtures of said mould are electrically insulated from the plant easing. I