CA1154365A - Method of electroslag welding by plate-type electrodes and flux used in the welding process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The invention relates to a flux for use in electroslag welding with a plate-type electrode, comprising: lithium fluoride; sodium fluoride; potassium fluoride; calcium fluoride the ratio of these components being as follows, % by weight:

lithium fluoride 60.0-90.0 sodium fluoride 5.0-20.0 potassium fluoride 4.0-15.0 calcium fluoride 1.0-5.0

Description

ME~HOD O~ ELEC~ROSLAG '.~ELDIN~ LA~ TY Æ ~LECT~ODES
AND ~L~X ~ED IN '~E UiELDING PROCESS

FI~LD 01? THE INVEI~IO~
~ he invention relates to welding and more particularl~
to èlectroslag welding by plate-type electrodes under the harm~ul influenc~ o~ external magnetic ~ields o~ high magne-tic inductionO
The e:~pression "ele~troslag welding by plate-ty~e electrodes" is used to denote electroslag welding metho~
characterized b~- the use of electrodes Iormed with plates of largo cros~ sectional areas, commensuIable with the gap between parts bei~g welded.
~ a~mful influences of external mag~etic fields upo~
the ~Jeldi~g process ma~i~est themselves, ~or example, durin~ the installation of heavy aluminium bus bars ~or .
reduction cells e~ployed at non~errous metallurgy and chemical industry pla~tse~ihere ex~ernal magne~ic ~ields are active.

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BACKG~OUND Oh' THE INVENTION

To date, the problem of weiding in external magnetic fields has not been solved ~o any satisfactory degree. Hand arc welding b~ nonconsumable electrodes in an inert atmosphere and under a blanket of flux ~ails to ensure the necessary weld quality~ particularly in installation o~ items 9 s~ch as reduction cell bus bars, featurin~ considerable thickness (100 to 200 mm3. Under usual conditions, this type of item cRn readily be welded-together by electroslag welding with plate-type electrodes. However, in strong external magnetic fields, the process becomes unstable due ~o the fact that in electro-slag ~elding a metal is melted by the heat of molten slag itself heated by an electric current passing therethrough (se~ ~lovar-spravochnik po svarke /welding Dictionary-~and-bookJ, "Naukova dumka" Publisher~" ~ie~ 1974~ p~l8~)o The external magnetic field acts upo~ the melt o~ slag and metal as a current conductor, imparting it a motion pulse leaaing ~o a loss of stability by the process mani~esting itself in a sharp misali~nment of velding pool open surface.
It has 3een experlme~tally found that satisfactory welds are obtain~ble if welding pool sur~ace deviates ~rom the hori zontal by not more ~han 15. A greater mlsalign~en~ resul~s in a sing~le-slded lack o~ penotration of edges beln~ welded and s~la~hlng of molten bath.

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~ here is known, for example5 a method for electroslag welding by a plate-type electrode (cf.USSX Inven~or's Cer-ti~icate No. 149,166).consisting in that parts being welded are set a specified dis-tance apart a~d provided with moul-ding arrangelnents composed of a pocket-type pan~ side moulds and top discharge planks intended to hold a slag bath at the ~inal stage of the welding processO A portion o~ wel~ing ~lux is placed into the pocket of t~e pan, then a plate-type electxode is in~roduced into the gap between edges o* parts being welded and connected to one of the poles of a source o~
welding current, ~he other pole being connected to parts being welded and the pan. ~he welding process is intitia~ed .
by ~aking the end face o* the electrode contac~ the pocket bottom, this produoing an electric arc which melts the pPr-tion of flux to form a slag ba-th. Molten slag being an elec-tric conductor, shunts the arc and so ini~iates the electro slag welding process consisting ~n that a ~Jelding current passes through and over~ea-ts molten slag~
In turn, the overhea~ed slag heats intensîvely the edge~ of parts being welded and the electrode, so that the metal they are made from melts~ ~he molten metal with a bla~{et o~ molten slag over it ~orms a welding pool, side areas of ~hich are forme~ beneath areas of non-fused metal of the ed-~es shaped as steps whose width corresponds to the depth of melting (penetra-tion) of the edg~es~ As metal melts~ the level Or -the melt i~ the gap rl es -to heat and melt ne~ areas :

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~ 3~5 of edges and o~ the electrode, the above steps and the weld-ing pool as if continually moving upwards~
At the same time, the metal solidifies in the bottom part o~ t~e ~elding pool producing a welding seam as the welding pool moves ~rom bottom up. '~he weld thus obtained ~eatures a high quality owing to homogeneity of weld metal and good weldin~ thereof to the metal o~ the parts involved.
Xowever, i~ the above electroslag welding process is carried out in an external ~agnetic field, the result is, due ~o the reasons menbioned~ a sharp misalignment of the welding pool surface ~UR to 90 from the horizontal), accompanied by projections o~ the welding pool melt from the gap. ~hese phenomena are encouraged by a relatively large open part of the welding pool surface~ becauc3e of which the magnetic field induced by the welding current ls incapable o~ neutrali~ing the action o~ the exter~al magnetic L ield througnout the open part of ~he melt sur~aGe c~nd o~ preventing a Yertical motion of the melt o~ any peripheral area o~ the surf`ace 9 this resulting i~ the misali~nment of the open par~ of the welding pool surfP e.
As meant here~ the ope~ part of the welding pool surface is the part of the melt surface limited by the projeotion o~ the gap area upon the abo~e sur~ace.
'~he term "gap area" is used here and below to denote the area limited by the edges of the par~s being welded, nu-merically equal to the product of the gap width by the edge , ~
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~5~1L3 ~ he misalignment of the open part of the welding pool surface increases the area wetted by the melt of one of the edges bein~ welded, so redîstributing the welding current between the edges. ~his, in turn, results in a lack of pene-tration on one of the edges and a more intensive melting o~ the other edge~ so that the step o~ non-melted metal on this edge acquires a gentl~ sloping shape o~fering no obstracle to the external magnetic ~ield to displace the melt previously con~
tained by the step, with ~he effect that the whole o~.the welding pool surface is misaligned, and the melt~ projected ~rom the gap A fairly wide gap, and, in consequence~ a large open ~Jeld-ing pool suxface axea are then necessary to prevent the harm~ul.
turbulen~ processes in the ~elding pool, as narrowing o~ the : :
gap hinders the removal of gases evolving actively as a result of the heating of the slag-~orming flux and causes a satura-: ~.
~ ~ion of the welding pool metal with gases.
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he texm "slag-forming flux" is used here and below to -; denote a welding ~Iux which is melted to create a slag bath.
Intensi~e evolution of gas ~uring welding process is due to that the currently employed fluxes boil readily under the :~ e~Yect of vJelding temperature and ~ive ol~ volatile co~pounds.
~his type o* fluxes includes, for example~ a flux Yor.welding . .
aluminium according to the U.~.~.R. Inventor's Certifi:cate No. 279~311~ containing in per cent ~ weight:
lithium fluoride 20 to 22 ., ,., ... - ,,- ~

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:~lS~L3~i sodium fluoride 28 to 30 potassium chloride 15 to 20 sodium chlorid~ 30 to 35 :
SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a method for electroslag welding by a plate-type electrode -~ and a welding flux ensuring the stability of the welding process in external magnetic fields through optimization of the dimensions of the open part of the welding pool surface Another object of the present invention is to raise the :~ boiling point of the flux.

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:~ The above and other objects of.the invention are attain-: ed in a method for electroslag welding by a plate-type elec-~ trode, comprising providing a gap between edges of parts ;~ being welded, introducing a plate type electrode into the gap and melting the electrode and the edges by the heat of an electrically heated slag to create an upward-moving welding pool, side areas of the surface thereof being formed, . ~
; as the edges melt, underneath moving steps of non-melting metal, according to the invention, parts to be welded are brought together to form a gap, the surface area "B" thereof . ~ being in a ratio to the area "A" of the horizontal cross ;
: section of the electrode and to the area "C" of the projec-;- tion of the surface of the welding pool upon a horizontal surface of A : B : C =

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-- ~ 5~ 5 = 1 (1.2 to 1.5 : (2.5 to 4.5) in order to keep the misa-lig~mcnt o~ the welding pool surface wi~hin 15 with the aid of the movîng steps~ which limit the ver~ical motion of the side areas of the welding pool surface, equal in area to between 40 and 75 per cent of the area thereo~, and o~ the ~ag-ne~ic ~ield of the elec-~rode.
'~he above method for electroslag welding by a plate-type electrode ~eatures stabili~y o~ the process in external mag~
netic ~ields through that9 for a given ratio of ~he sur~ace areas A, B, C, the open part o~ the welding pool surface has such dimensions that the magnetic field of the plate-type ele-. i .
~;~ ctrode neutralizes the action of strong external magnetic ~ields and prevents splashing o~ the melt. Additionally~ the movin~
steps have su~icient dimensions and a ~avourable shape for conta~ing the side areas of the welding pool sur~ace notwith standing the action of the external magnetic fields.
It is good practice to impart the moving steps a speci-;~ fied shape by applying upon the edges of parts being welded ~ an electric insulating material having a breakdown te~perature i . . .
r" aDove the melting point "~m" of the metal o~ ~he par~-s ` ~ being welaed by a Xactor o~ 1.1 to 1.5~
Placing ~he ~oving steps in a specified position, for exam-ple, close to a hor~zontal one, enhances ~heir capability o~
preventing the misalign~ent of the side areas of the welding pool.surface under the action o~ external magnetic ~ields.
~; The moYi~g steps acquire a specified shape because the .. . .

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3ti5 insulating material restricts the wetting of the unmelted metal by the melt 9 and, there~o~e 3 the i~ensity o~ the thermal actionJ to predetermined areas. If Tbr~l l Illm, -the electric insulating material will bre~ down below the surface of the slag bath, and so no specified shape of steps will be obtained. I~ ~ r> 1.5 ~m' the insulating material will not have enough time to break ~own completely before it comes into contact with the metallic bath~ this resulting in slag inclusions in the weld.
The electric insulating ~aterial should pre~erably con-tain a non-organic compound - sal~ - and/or mixture of salts of ~a, Na, R, l~g~ Ca, Zn, B~ Al and /or their oxides and/or their carbidesJ as these compouncls possess the necessary ther-mal chara~teristics.
It is also suggested that the electric insulating ma-terial contain an organic compound, such as cellulose, ve-neer, organic resi~, as this type of materials possess the necessary thermal characteristics and, additionall~, can rea-dily be secured to the sur~ace o~ edges o~ parts to be wel~
ded.
~ he above and other objects are at~ained also by providing a ~lux for electroslag ~eldin~, co~prising lithium fluoride and sodium ~luoride, and accor~i~g ~o the invention, additi~
onally containing potassium fluoride and calcium ~luoride i~
~he folloYling proportions, per cen~ by weights .
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lithium ~luoride 60 0 to 9000 sodium ~luoride 5.0 to 20.0 calcium i~luoride 1.0 to 5~0 potassium ~luoride 4~ to 15.0 'l'he above ~lux has a boiling point higher than the wor-king electxoslag welding temperature, this sharpl~ reducing .
gas evolution during welding, requiring no large gap between : the edges o~ parts being welded for rémoval o~ the gase~ and making it possible to aecrease ~he surface area o~ the open part o~ the sur~ace o~ welding pool.~ so as to, as mentioned, stabilize the welding process where carried out in an e~rternal magnetic field.
~: It is also advantageous to provide a calcium ~luoride to : sodium fluoride ratio o~ l-to-5, the proportions of all the components being as ~ollows, per cent.by wei~ht:
; lithium fluoride . 60.0 to 90.0 sodium ~luoride 5.0 to 20.0 : calcium ~luoride 1.0 to 4.0 . : potassium fluoride 4.0 to 15.0 The above calcium ~luoride to sodium ~luoride ratio achi-eves a maximum activit~ of the ~lux wit~ respect to a metal ` . bein~ welded. .
- BRIEF DESCRIP~ION OF.~ Æ DRA'.I/INGS
; ~hese and other objects and ~eatures o~ the inventio~
become readil~ apparent ~rom one embodime~t thereo~ whic~ ;

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-- lo --will now be described b~ way of example with reference to the accomp~nying drawings, in which:
~ ig~l is a schematic longitudinal vertical section of a ~eneral weldi~g setup with moulding arrangements for assemb-ling par~s to be welded a~d car.rying out the electroslag welding method, according to the inventio~;
~ igo2 is a schematic longitudinal vertical section of a setup with moulding arrangements for parts to be welded whose edges are half covered v~ith an insulating material;
Fig.3 is a schematic horizon~al ~.ection of a setup9 in-cluding moulding arrangements, ~o:r asse~bling parts to be welded with selectively coated su:r~aces of edges;
~ ig.4 is a schematic horizon~al section o~ a setup with moulding arrangements ~or a heavy single-piece part and an assembled packet o~ parts;
~ ig~5 is a scheamtic long~itudinal vextical section of a setup~ including moulding arrangeulellts, lor parts ~o be wel-ded with alterna~ive coating o~ edges for ~elding elements o~ various heàt remo~al capacities.
D~SCRIPTIO~ 0~ '~HE ~REFE~ED E~BODI~E~æ
The methoa ~or electroslag welding is carried out in an ac-ti~e magnetic ~ield having a magnetic induction o~ up ~o 40 or 45-10-3 ~.
~ he edges of parts 1 and 2 ~see ~ig~l) to be welded, for example7 bus barsD are coated with an elec-tric in~ulating , .:
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- material 3 having a breakdo~nn temperature ~b~ by a Y'actor of 1.1 to 105 higher tha~ the melting point ~m of the parts9 not less than 50% of the sur~ace area of the edges being coated and the parts being positioned so as to provide a gap between the ed~es~
r~he moulding arrangements consisting of a pan 4 having a : pocket 5, side ~oulds 6 and top discharge planks 7 are mounted : nex~ o~ the parts ~ and 2. A portion o~ a slag-forming ~lux . is chargea into ~he pocket 57 the composition o~ ~he Ilux .being as rOllows ~ per cent by weight:
lithium fluoride 60.0 to gO.0 . sodium ~luoride 5~0 to 20.0 :
calcium fluoride . 1,0 to 5.0 potassium fluoride 4.V to 15.0 A plate-type electrode 8 co.nnected ~o one of the poles o~ a weldI~g current source (omit-ted on the drawings) is introduced into the gap, the o~her pole of the welding cur-rent source being connected to the parts t~ be welded 1 and

2 and the pan 40 ~ he parts 1 and 2 are brou~ht together so as to ~orm the gap ~hose surface area I~BII is in a ratio to the surface area "A" o~ the horizontal cross section of the electrode of A : B - 1 : (102 to 1.5~.
Thc welding process is started by bringing the end ~ace of the electrode 8 into contact wi-th the bottom of the pocket :~
5, this initiat~ an électric arc which melts the e~cve por-`' ~

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, 5~ 3~5 tio~ of flux to produce a ~ath 9 of molten slag. q~he molten slag shunt~ the arc, and ~o starts the electroslag welding pro-cess, A welding current passes through and overheats ~he molten slag7 the heat ~hereo~ causing, in the areas vrhere the slag comes into direct contact with the metal of the electrode and of the edges o~ the parts to be welded; an intensive mel-ting o~ the metal which flows i~to the pocket 5~ The molten metal together wit,h the bath 9 o~ molten slag coveri~g it ~orms a welding pool 10 whose ~ide areas are formed beneath areas o~ non-melted met-al of the edges having the shape of moving steps 11 and 12 whose width correspo~ds to the depth of pe-netration of the edges. ~he depth of the penetration îs such that 4he area "A" and the horizontal cross sectional area of the elec~ro~e are in a xatio to the area "C" of the pro-jection of the sur~ace o~ the welding pool upon a horiz~ontal plane of 1 : (2.5 to 4.5)0 'l'his is achieved by adjusting ~he ;
parameters o~the welding process Iw and U~l, which are espectively the intensity ol the welaing current an~ the no-load voltage of the welding current sourceO
As the edges of the parts 1 and 2 are coated lvith an electric insulating ~aterial 3, the moving steps 11 and 12 are in a position close to the horizontal~ as the area o~ the intensive thermal actio~ of the slag bath 9 upo~ the metal of the ~arts 1 and 2 is limited to that o~ direct contac~
'l~he ex~ernal magnetic Yield acts upon the welding pool 10 as upon a cur.rent conductor~ impar~lng a motion pulse there~o.

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However, since the process is carried out at the specified ratio o~ the surface areas ~a B~ C~ the open part of the sur~`ace o~ the welding pool 10 has such a si~e that the magnetic *ield of the plate-type electrode 8 neutralizes the action of the external magnetic fi~ld, whereas ~he moving steps 11 a~d 12 have sufficient dimensions and a shape adequate ~or restricting the displacement o~ the side areas of the welding pool sur~ace. ~his enables the misalign-ment o~ the welding pool to be kept within the range of 0 to 15 from the horizontal and the e~ect o~ tne external magnetic ~ield to be neutralized. ~he welding process acquires stability with the effec~ that the welding pool rises without ~isalignment up the gap as the metal of the edges and o~ the electxode melts and the steps 11 and 12 move upwards~ At the same time, the metal solidi~ies Ln the bottom part o~ the welding pool to form a weld.
The invention will now be described by the ~ollowi~g illustrative Examples.
Example 1.
Aluminium bus bars 1 and 2,140 mm thick9 are electro-sIag-~elded in a magnetic field of a magnetic i~duc-tion of 40010 3 ~. ~dges to be welded of bus bars have been coated in advance with an electrlc insulating ma~erial 3 based o~
NaCl whose breakdown tempe~ature is ~br_800 to 900C; i.e~
by a ~actor of l.2 to 103 higher than the melti~g poi~t ~m ~ 660C of aluminiumJ A welding plate-txpe electrode 8 ~4365 rrom aluminium was 20 mm thic~ ~he process was stabilizedby providing a ratio of A : B : a = 1 1~2 : 2.5, the ~idth of the gap between the welding edges and the depth of pene_ tration o~ the vlelding edges having been accordingly calcula-~: tea equal to respec~ively ~4 and 13 mm.
In accordance with the calculations, bhe bus bars 1 and2 were-brought together to provid~- a gap between the edges o~
24 mm.
~ ouldi~g arrangements consisting a pan 4 with a pocket 5, ::
side mould~ 6 and top discharge planks 7 were asse~bled on ~he bus bars 1 and 2.
As the boiling point ~bsl OL the slag-~orminb~ I`1UX had to be greater than the welding temperature of the aluminium :~
bus bars ~W=1200 to 1400C, the flux had the compositio~ below, % bg weight:
lithium ~luoride 60,0 sodiu. fluoride - 20~0 ; ~ calcium fIuoride 5.0 : potassium fluoride 15.~ :
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the boil.~ng poi~t being Tb=1500C.
`~ A portion of slag-forming flu~ was charged into ~he po-cke~ 5. A plate-type electrode 8 was then Introduced into ^~
.
: the gap, and a~ electroslag welaing process was initiated5 A required depth of pene-tration was aohieved by conducting the process;under the conditions belo~Y: . :
I = 7 0 kA
' ,'' U~L = 44 V
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~ he resulting moving steps 11 and 12 had a position close to the horizontal~ and the misalignment of the surface of the weldîng pool was not more than 15C.
The effect o~ this procedure was a quality bus bar weld 50 mm vide.
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Example 2 Ingots of an alloy based on aluminium and containing 5-8%
-~ magnesium, 140 mm thick, were electroslag-welded i~ a mag~etic field of a magnetic induction o~ 40-10 3 ~
~ The melting point o~ t~e alloy was ~m-654C. ~dges were `~ insulated electrically with a coat of Na3A1~6 having a break-dowm point o~ ~b~=1000C.
The plate type electrode was 20 mm thick.
~;~ The ratio of the areas was A : B : C = 1 : 2.3 : 3 5.
Gap width was 26 mm.
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~dge penetration depth was 22 mm.
Welding conditions :

' ' W
Unl = 42 V
The weldi~g ~emperature: ~W=1200 to 1400C.
The ~lux had the chemical compos~ion below, % by weight:
- lithium ~luoride ` 90.0 sodium fluoride 5~0 calcium ~luoride 1.0 ~ potassium fluoride 4.0 .: ~; , . .
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~he boiling point of the flux was Tb=1~10C.
~ he moulding arrangements were assem~led, and the elec-troslag welding process, initiated, as in the EXAI~LE lo The misalig~ment o~ the sur~ace o~ the welding pool was not greater than 15 from the hori~ontal. ~he result o~ the above proce-dure was a quali~y weld, 70 mm wide~
~xample 3 ~ orgingswere elec~roslag-welded in a magnetic ~ield o~ a ma~netic induction of 40-10-3~i.
The material of the Y`orgings a~d o~ the electrode was an iron alloy containing, ~ : C, 0.10; Si, 0.54; M~, 1.10;
Cr, 17.75; ~i~ 9.3; ~î, 0.51; Fe, the balance to 100.
~ m = 1385 C~
In~ot thickness was ~00 mm.
The coat material was a mix~ure o~ MgSo~ a~d A1~03 take~
in a ratio o~ l-to-l.
br=1530 C.
The coat was applied over 5C ~ of` the area o~ edges, their ~op part (see ~ig.2). 'l'his led to a more intensive . ~ ~
initial st-age of ~he welding process with the position of ~he st-ops being kept close to the horizontalO
The plate-t~pe electrode was 12-mm thick~
'he ratio o~ the areas was A : B ; G _ 1 ; 1.5 : 4.5 , Gap width was 18 mm.
E~ge pe~etration depth was 18 mm.
- W~lding oonditions:

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I = 6 kA
U = 3g V
nl The welding temperature was Tw = 1540C.

The flux employed had the following composition, ~ by weight:
lithium fluoride 70.0 sodium fluoride 20.0 calcium fluoride 4.0 potassium fluoride 6.0 Tb = 1570C.

The moulding arrangements were assembled, and the elec-troslag welding process, initiated, as in the EXample 1.

Welding pool surface misalignment was not greater than15 from the horizontal.

The procedure resulted in a quality forging weld, 54 mm thick.

Example 4 Forgings were electroslag-welded in a magnetic field of a magnetic induction of 40-10 T.

The material of the forgings and of the electrode was an `~ iron-nickel based alloy containing, %: C, 0.04, Si, 0.51;
30 :Mn, 0.27; Cr, 19.60; Ni, 27.80; W, 4.78; Mo, 2.90; Nb, 1.05;
Fe, the balance to 100.
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T~ = 1320C.
Ingot thickness was 100 mm.

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The material of the coat was mixture of Na2O, K2O, Li2O, CaO taken in a ratio of 1 : 1.1 : 1.

Tbr = 1440C.

To econ~mize the material, the coat was applied onto the boundaries of the edges to be welded (see Fig. 3) so as to ; cover 50~ of the surface area thereof. The moving steps remained practically horizontal during welding.
' The plate-type electrode was 10 mm thick.
The ratio of the areas was A : B : C = 1 : 1.3 : 3.5.
The gap width was 13 mm.
The edge penetration depth was 11 mm;
; 15 The welding conditions w~re as follows:
W = 2.0 kA
nl = 36 V

The welding temperature was Tw = 1500C.
The composition of the flux, % by weight:

lithium fluoride 85.0 sodium fluoride 4.0 25 calcium fluoride 4.0 potassium fluoride 7.0 Tb = 1515C.

The moulding arrangements were assembled, and the electroslag-welded, initiated, the same as in Example 1.
The misalignment of the welding pool surface was not greater than 15 from tlle horizontal. The procedure yielded a quality weld of the forgings, 35 mm wide.

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Example 5 : Bus bars were electroslag-welded i~ a magnetic ~ield of a magnetic induction of 40-10 3 ~
Material of the bus bars and ~he electrode was copper.
= 1080C.
m ~us bar thickness was 100 mm.
l'he material of the coat was based o~ NaF
~r = 1420C.
~he pla~e-type electrode was 20 mm thick.
The ratio of the areas was A : B ^ C = 1 ~ 1.5 : 4.5.
'~he ~ap wid~h was 30 mm.
~he edge penetratio~ depth was 30 mm.
: ~Yelding conditions:
IW = 10 kA
Un~
. ~w = 1~50C
: ~Iux composition, % by weigh~:
lithium ~luoride 90~0 sodium fluoride 5 0 calcium fluoride 1.0 ~: potassium fluoride 4.0 ~I!b-1505 C .
~he mo-1ldin$ arra~gemen~s were assembled, ~nd the ~ elec~roslag welding process, initiated, the same as in the : . ~
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-- 2~ --~ he misalignment o~ ~he welding pool surface was not ~reater than 15 from the horizontal.
~ he procedure yielded a qualit~ i~got weld 90 mm thick.
Example 6 Aluminium bus bars were electroslag welded in a ma~netic field. The bus bar 1 was.fo~ed with an ingot, and the bus bar 2, with a package of sheets (see ~ig.4). ~he magnetic in-duction of the ~ield was 40-1~ 3 To ~ The bus bars were 140 mm thick.
Tm = 660C.
The material of the coat a veneer sheet 2 mm thicko ~ br = 730-750C.
: ~he edge o~ the bus bar 2 was covered completel~9 and the edge of the bus bar 1, from the top to hal~ their width (see ~ Fig,5), this to allow fox the di~ferent heat removal proper-; ties of the bus bars 1 and 2.
~ he plate-type electrode was 20 mm thick.
~ he ratio of the areas was A:B:C = 1 : 1~2 :,2.50 ~he gap width was 24 mme ~he edge pene~ration depth v~as 13 mm. . . ..
Welding conditions~

w = 7~ kA
Unl = ~ V ' .' . ~w = 1200~C. . -~ he composition of the flux was as follows, % by wei~ht~

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lithium fluoride 75.0 sodium fluoride 15.0 calcium fluoride 3.0 potassium fluoride 7.0 tb = 1500C.

The moulding arrangements were assembled, and the elec-troslag-welding process, initiated, the same as in the Example 1. The misalignment of the welding pool surface did not exceed 15 above horizontal line level.
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The procedure yielded a quality weld 50 mm thick.
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~; Example 7 Items were welded in a magnetic field of a magnetic induction of 40-10 T.

The material of the forgings and of the electrode was an iron~based alloy containing, %: C, 0.10; Si, 0.54;
Mn, 1.10; Cr, 17.75; Ni, 9.3; Ti, 0.51; Fe, the balance.
T - 1385C.
m Thickness of the forgings was 140 mm.
The material of the coat was~ rosin with a CaO filler.
Tbr = 1530C.
The thickness of the plate-type electrode was 12 mm.
The ratio of the areas was A : B : C = 1 : 1.5 : 4.5.
The width of the gap was 18 mm.
The depth of penetration of the edges was 18 mm.
Welding conditions:
w Unl = 38 V

.

:
, :

. ...... ~

. ~ :

- .

3~5 = 1540C.
~he composition of the ~'lux was as ~ollows, % by weight:
lithium fluoride 65.0 sodium fluoride , 2000 calcium ~luoride ' ~.0 potassium ~luoride lOo O

~b= 1550 C.
The moulding,arrangements were assembled; and the electro-slag welding process, ini-tiated, as in the EXAN~ 1. The mi-salignment of the weld~ng pool was not greater than 15 ~rom the horizontal.
The above procedure yielded a quality weld of the forgings~ 54 mm wide.
~xample ~
The ~orgings vJere electroslag-w01ded in a magnetic field o~ a magnetic induction of 40-10 '3~.
~he ma~erial o~ the forging~ and of the electrode was a~
aluminium-based alloy containing 5.8 ~0 magnesium.
~m = Z54 C-~he thickness o~ the ingots was 140 mm.
~he material o~ the coa~ was based on celluloseO
~br = 73 C9 '.
~' The thickness o~ the plate-t~pe electrode ~as 20 mm.
~he r~tio of the areas was A : B : C = 1 ~ 3.50 The width o~ the gap was 26 mm.
. ' ' , .
' .~ , : ~ ' ~5~3~5i The depth of the penetration of the edges was 22 mm.
Welding conditions were as follows:
Iw ~ 9-5 kA
U 1 = 42 V
T = 1100C.
: w The composition of the flux was as follows, % by weight:
lithium fluoride 75.0 sodium fluoride 15.0 calcium fluoride 3.0 potassium fluoride 7.0 Tb = 1490C.

The moulding arrangements were assembled, and the elec-troslag-welding process, initiated, as in the Example 1.
The misalignment of the surface of the welding pool was not greater than 15 from the horizontal~
. .
The procedure yielded a quality weld of the forgings 70 mm wide.
: ..
Example 9 ,: ~
Ingots were electroslag-welded in a magnetic field of a~magnetic induction of 40-10 T.
~ ~ .
The material of the forgings and of the electrode was an iron-and-nickel-based alloy containing, ~: C, 0.04;
` Si, 0.51; Mn, 0.27; Cr, 19.6; Ni, 2708; W, 4.78; Mo, 2.9;
Nb, 1.05; Fe, the balance.
Tm = 1320C- i The thickness of the ingots was 100 mm.
The material of the coat was laminated insulation.
:

.~ ' ' :

:

ti~

'l'br - 1460C.
~he thickness of the plate-type electrode was 10 mm.
l'he ra~io of the areas was A : ~ : C = 1 : 1.3 : 3.5.
~he wid~h of the gap was 13 mm.
lihe ~epth of penetration of the e~g~3 was 11 mm.
Welding conditions: .
Iw = 2.0 kA
Unl = 36 V~ ~-= 15~0C.
The composi~ion of the flu~ was as follow~ % by ~eight:
!,. lithium fluoride 75.0 ~ ; -sodium fluoride 15.0 calcium fluoride 3.o i.
potassium fluoride . 7.0 ..
~_ 1510C. .
.. ~he moulding arrangements were assembled, and the electro-slag welding process9 initiated? the same as in the ~X~IE 1.
The misaligment of the welding pool surfac~ was not greater than 15 from ~he horizontal~
~he procedure yielded a qualit~ weld of the forgings, 35 mm wide.
~` ~xample 10 ~us bars were electroslag-welded in a magnetic ~ield.
~he magnetic induction of the *ield was 40-10 3 ~.
~he material of ~he ingots (bus bars) and of the electrode was copoer.

- . -~5~3~i Tm = 1~80C.
'~hickness o~ the ingots was 100 mm.
~he material of the coat was teX~olit.
~br = 1420C.
~he thickness o~ the plate-type electrode was 20 mm.
~he ratio of the areas A : B : C = 1 : 1~5 î 4~5 The width ol the gap was 30 mm.
'~he dept~ o~ the penetration of the edges was 30 mm.
Welding co~ditions:
Iw = 10 kA
Unl = 44 VO
'~w = 1450~.
The co~position o~ the ~lux was as ~ollows, % by weight:
lithium ~luoride 80.0 sodium ~`luoride 10.0 calcium fluuride 2.0 ~ . , .
potassium fluoride 8.0 ~b - 1505C.
~ he moulding arrangements were asse~bled, and the electroslag welding process, initiated, the same as i~ the-XA~ E lo ~he misalignment of the weldi~g pool su~facewas not grea~er than 15 ~rom the horizo~tal.
'~he procedure yielded a quality weld o~ the ingots, 90 mm wide.
' ' ' .
, ~- . . , . ~
: ```' " ' `

- ~

Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A flux for use in electroslag welding with a plate-type electrode, comprising: lithium fluoride; sodium fluoride;
potassium fluoride; calcium fluoride, the ratio of these com-ponents being as follows, % by weight:
lithium fluoride 60.0-90.0 sodium fluoride 5.0-20.0 potassium fluoride 4.0-15.0 calcium fluoride 1.0-5Ø

2. A flux as claimed in claim 1, wherein calcium fluoride and sodium fluoride are contained in a ratio of l-to-5, the proportions of the components being as follows, % by weight:
lithium fluoride 60.0-90.0 sodium fluoride 5.0-20.0 calcium fluoride 1.0-4.0 potassium fluoride 4.0-15Ø