CA1195218A - Welding flux - Google Patents
Welding fluxInfo
- Publication number
- CA1195218A CA1195218A CA000434337A CA434337A CA1195218A CA 1195218 A CA1195218 A CA 1195218A CA 000434337 A CA000434337 A CA 000434337A CA 434337 A CA434337 A CA 434337A CA 1195218 A CA1195218 A CA 1195218A
- Authority
- CA
- Canada
- Prior art keywords
- welding
- weld
- metal
- fluoride
- electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K25/00—Slag welding, i.e. using a heated layer or mass of powder, slag, or the like in contact with the material to be joined
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
- B23K35/3601—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest with inorganic compounds as principal constituents
- B23K35/3603—Halide salts
- B23K35/3605—Fluorides
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Nonmetallic Welding Materials (AREA)
- Arc Welding In General (AREA)
- Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention relates to a flux for carrying out a method of electroslag welding of light metals.
The flux includes the following composition (in wt.%):
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1.0 to 15Ø
The invention relates to a flux for carrying out a method of electroslag welding of light metals.
The flux includes the following composition (in wt.%):
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1.0 to 15Ø
Description
~ET~OD, WELDING F~U~, AND APPARATUS ~OR EIECTRO-. SLA~ WELDING
The present invention relates to the art Qf ~elding and more particularly to a method for electroslag welding of li~ht metals and alloys with a de~sit~ less than that of the slag, to a weldin~ flux based on alkali and alkali-earth metal halides, and to apparatus for accomplishing said method.
The i~vention may be employed i~ welding ~luminium, magnesium, titanium, their alloys, and other light metals;
it is particularly useful for welding aluminium busbars in the nonferrous metallurgy 9 chemical and electrical in-dustries, and in other fields of engi~eeringD
There is known a method for electroslag welding of metals (~lektroshlakova;ia svarka (~lectroslag welding) ~d. by B.Ye. Paton. Moscow-Kiev, '~ilashgiz" Publishersg 1959, pp. 90-1493, which includes establishing a slag bath,~us-ing an electrode and edges being weld-aoined7 and filling the gap between the edges with molten metal.
It is known that in the course of electroslag weld-ing of light metals and alloys with the use of prior art fluxes~ the content of gases in the weld metal rises with the thickness of the workpieces being weld-joined.
~ or example, a flux has been proposed (USSR Invent-or's Certificate No. 626,913) intended for electroslag welding of light metals and alloys and containing alkali and alkali-earth metal halides, the ~lux composition be-.~
~52~
ing as follows (in wt %~:calcium ~luoride O . . . . . . . . 13-17 strontium ~luoride . . I . . . . . . 1~-17 magnesium fluoride . . . . . . . . . 10-14 lithium fLuoride . . a ~ o 16-20 potassium fluoride (concentrated aqueous solution) . O . . . . . . . ~6-44 A weld produced with the use o~ the flu~ in the co-urse o~ weldin~ 9 without resorting to known techniques ~or reducing the gas content in the weld metal, is porous and has an increased content of gases, which drastically im-pair5 the mechanical properties o~ ~elded joints Further-more, the flux is highly hygroscopic (because its comp~-sition includes a concentrated aqueous solution of potas-sium fluoride), which in the course of electroslag weld-ing may give rise to weld pool splashouts upsetting the stabili ~ o~ the process~
The above-men-tioned electroslag welding method con-templates the use o~ apparatus consisting of a bottom plate, mouldin~ shoes, run-on plates, and a ~elding electrode.
The use o~ such methods, flu~, and a~paratus results in welds featurin~ an increased content of gas and calls for additional ~rocessing operations to upgIade the weld.
quality in ~elding critical structures~
A ~ull degassing o~ the weld me-tal in the above me-thod can be attained with inhibiting the weld metal cry-stallization process by performing an additional operation of a preliminary, accompanying, and subsequ`ent heating of .
, the weld metal, which is attainable only by the use of a com--plex additional equipment.
Moreover 5 the method calls ~or introduction in the course of welding into the weld metal of additio~al che-mical elements which bind the gas-formin~ components for preventing the formation of gas bubbles and ~or a~ addi-tional protection of the welding zone by inert gasesD
The application of said method, flu~, and apparatus involving the additional processing steps greatly increas-es the labour consumptio~ and the cost o~ the welding pro-cess~
There has also been proposed a method for vertical welding of aluminium (US Pat. No. 3,585,343) 9 w~ich includes establishing a slag bath o~ the ~ollowing compositio~ (in %):
potassium chloride . . . . . . . . . 45 sodium chloride . . ~ 27 s~dîum cryolite (~NaF.AlF~ . . . . 22 ( lithium chloride . . . . . . . . . 6, followed by ~using the electrode and the edges being weld joined and ~illing the gap betwee~ the edges with metal.
The above ~lux allows a stable electroslag welding process to be conducted, adequately deoxidizes an oxide ~ilm on the workpieces being weid-joined, but ~ails to en-sure sound welds unless the above-mentioned weld metal de-gassing techniques are resorted to~
The method contemplates the use o~ an apparatus com-prising a metal mould, graphite moulding shoes, current con-tact members, and a solid-section electrode with a guide bushing which provides ~or its rotation in the slag bath;
the current contact members are disposed outside the weld pool.
Degassing thé weld in the course of vJelding proceeds owing to the use of the graphite moulding shoes which re-duce the heat removal from the weld pool as well as to the electrode rotation in the slag bath~
Because of a h~gh rate of the weld metal crystalli-zation as well as o~ that the elec-trode rotation exerts 1 a mechanical ef~ect on the slag bath alone in the course of welding, this prior art method is incapable of fully degassing the weld metal~
The electroslag welding method with the use of the above-described flux and apparatus necessitates a complex follow-up equipment to ensure stabilit~ o~ the ~rocess thro-u~h controlling the electrode disposition in the weld pool~
which complicates the process, raises its cost, and still Yails to ~ully remove gases from the weld metal be~ore its crystallization because of a lo~ melting point o~ the flux.
The principal object of the present invention is to provide a method, a welding flux~ and an apparatus for electroslag welding of lig~ht metals and alLoys~ which en-sure a stable v~elding process and minimize the gas content in the weld metalO
An object of the invention, following from the pre-ceding one, is to provide a weldin~ f.lux whose quantitative and qualitative composition raises the heat capacity of the slag bath and thereby ensures the degassing of the liquid metal of the weld.
A further object of the invention is to widen the production possibilities of the method.
Still further object of the invention is to cut down the labour consumption of the welding process.
Yet further object of the inven-tion is to raise the productive capacity of the welding process.
An object of the invention is also to cut down the cost of production of weld joints.
Still another object of the invention is to provide an apparatus for electroslag welding, which ensures remo~-al of gases from the weld pool in the course of welding and self-regulation of the electrode fusion rate.
In accordance with a particular embodiment of the invention, there is provided a flux for the method of electroslag welding of light metals having the following composition (in wt.%):
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1~0 to 15Ø
This allows a weld joint with a sound weld metal to be obtained.
The slag bath heat capacity may be raised by increas-ing the bath volume. This slows down the rate of weld me-35~8 tal cooling in the course o~ welding.To raise the.slag bath he~t ca~acity a flu~ of the following composition (in %) is used:
barium fluoride . ~ . . . . . . 60.0 to 90.0 calcium ~luoride ~ . . . . . . . 5.0 to 15.0 lithium ~luoride . . . . . . . . 1~0 to 5~0 sodium fluoride . 0 . . . . ~ 0 to lOoO
potassium fluoride . . ~ . . . . 1.0 to 15,0 - I~corporation of barium fluoride in the above-speci-fied amounts into the proposed flu~ increases the flux density above that of the metal being ~elded~ and there-by facilitates separation of molten metal from slag in the course of electroslag welding as well as provides the sta-bility of the process.
Reducing the barium fluoride content in the propos-ed flu~ below the specified lower limit leads to a poor separation o~ molten metal ~rom slag in the process and impairs the stability of the latter, whereas e~ceeding the s~ecified upper limit reduces the activit~ o~ the flu~ and eventuallg results in weld de~ectsO
Incorporation of calcium fluoride in the above-spe-cified amounts into the composition of the proposed flux augments the activit~ of the latter and also, throu~h re-ducing the sur~ace tension at the slag-metal interface, pro-motes the merging of i~dividual liquid metal drops into one metal pool in the course of electroslag welding. Reduc-ing or increasing the calcium fluoride content in the pro-posed flux composition beyon~ the above-specified range s~
degrades the activity of the flu~.
Lithium, sodi~um, and potassium fluorides contained in the above-sPecified amounts in the composition of the proposed flux as well enhance its activit~.
The above-specified percentages of the flux compo-nents raise the flu~ melting point above -that of the metal being welded, which results in inhibiting the crystalliza-tion o~ the molten metal in the gap between the edges be~
ing weld-joined and hence in a higher degree of degassing the metal and in producing a sound wèld. ~he above advant-ages of -the proposed flux allow the qualit~ and operational dependability of welded joints to be greatly enhanced~
Increasing the heat ca~acity of the slag bath and holding the weld metal in a liquid state till its degass-ing in accordance with the proposed method are attained with the use of an apparatus which includes a metal mould with a bottom plate 7 moulding shoes, a current contact member, and a welding electrode, in which apparatus the welding electrode is installed through an aperture in the bottom plate centre and a lo~-resis-tance current contact member is installed in the electrode fusion zoneO
Such an arrangement provides for a stability of the v~elding process owing to a self-regulation of the v~elding electrode ~usion rate, since ~vhen the electrode end gets fused down below the top plane of the current contact mem-ber, the arc spot shifts from the electrode to the current lead member, thereby slo~ving do~n the electrode fusion rateO
The current contact member installed in the electrode ~usion zone may be made of either a solid material whose melting point exceeds the working temperature of welding or a liquid material whose boiling point e~ceeds the work-ing temperature of welding.
When thus selected, the current lead member material is not destructed i~ welding.
When a liquid material is chosen for the current con-tact member; the material is selected so that its density exceeds that of the slag bath and so that it neither mixes with ~or dissolves in the liquid electrode metalO
( Such a selection of the material precludes contamina tion of the weld metal with the CurreQt contact member ma-terial in the course of welding.
Preferable is such a modification of the electroslag welding apparatus wherein the electrode has internal pass-ages disposed along and across the electrode, ~illed with a gas-conducting material, and communicating with a simi-lar passage in the metal mould bottom plate.
The provision of such passages permits removal of gas-es from the weld pool ln the course of welding, while fill-ing the passages with a gas-conductin~ material prevents the weld pool from .~lowing out o~ the gap bet~een the edges being ~eld-.ioined~
The inven-tion will now be explained in greater de-tail with reference -to the accompanying drawings~ in which~
~ ig. 1 illustrates the process of electroslag welding of light metals and alloys according to the invention, with a solid c~rrent COQtact member;
~ ig. 2 illu~trates the same as ~ig. 1, but with a li-quid current contact member;
Fig. 3 illustrates the F~ocess of holding the liquid weld metal on a high-temperature hearth, after switGhin~
off the welding current; and ~ ig. 4 shows the obtained weld after crystallizatio~
~ ne invention is explained by way of specific ~xa-mples thereof~
E~ample 1 ~ lectroslag welding of workpieces vas carried out in an apparatus which was prepared for weldin~ b~ the ~ol-lowing procedure.
50~100-mm section9 500 m~ long aluminium sDecimens
The present invention relates to the art Qf ~elding and more particularly to a method for electroslag welding of li~ht metals and alloys with a de~sit~ less than that of the slag, to a weldin~ flux based on alkali and alkali-earth metal halides, and to apparatus for accomplishing said method.
The i~vention may be employed i~ welding ~luminium, magnesium, titanium, their alloys, and other light metals;
it is particularly useful for welding aluminium busbars in the nonferrous metallurgy 9 chemical and electrical in-dustries, and in other fields of engi~eeringD
There is known a method for electroslag welding of metals (~lektroshlakova;ia svarka (~lectroslag welding) ~d. by B.Ye. Paton. Moscow-Kiev, '~ilashgiz" Publishersg 1959, pp. 90-1493, which includes establishing a slag bath,~us-ing an electrode and edges being weld-aoined7 and filling the gap between the edges with molten metal.
It is known that in the course of electroslag weld-ing of light metals and alloys with the use of prior art fluxes~ the content of gases in the weld metal rises with the thickness of the workpieces being weld-joined.
~ or example, a flux has been proposed (USSR Invent-or's Certificate No. 626,913) intended for electroslag welding of light metals and alloys and containing alkali and alkali-earth metal halides, the ~lux composition be-.~
~52~
ing as follows (in wt %~:calcium ~luoride O . . . . . . . . 13-17 strontium ~luoride . . I . . . . . . 1~-17 magnesium fluoride . . . . . . . . . 10-14 lithium fLuoride . . a ~ o 16-20 potassium fluoride (concentrated aqueous solution) . O . . . . . . . ~6-44 A weld produced with the use o~ the flu~ in the co-urse o~ weldin~ 9 without resorting to known techniques ~or reducing the gas content in the weld metal, is porous and has an increased content of gases, which drastically im-pair5 the mechanical properties o~ ~elded joints Further-more, the flux is highly hygroscopic (because its comp~-sition includes a concentrated aqueous solution of potas-sium fluoride), which in the course of electroslag weld-ing may give rise to weld pool splashouts upsetting the stabili ~ o~ the process~
The above-men-tioned electroslag welding method con-templates the use o~ apparatus consisting of a bottom plate, mouldin~ shoes, run-on plates, and a ~elding electrode.
The use o~ such methods, flu~, and a~paratus results in welds featurin~ an increased content of gas and calls for additional ~rocessing operations to upgIade the weld.
quality in ~elding critical structures~
A ~ull degassing o~ the weld me-tal in the above me-thod can be attained with inhibiting the weld metal cry-stallization process by performing an additional operation of a preliminary, accompanying, and subsequ`ent heating of .
, the weld metal, which is attainable only by the use of a com--plex additional equipment.
Moreover 5 the method calls ~or introduction in the course of welding into the weld metal of additio~al che-mical elements which bind the gas-formin~ components for preventing the formation of gas bubbles and ~or a~ addi-tional protection of the welding zone by inert gasesD
The application of said method, flu~, and apparatus involving the additional processing steps greatly increas-es the labour consumptio~ and the cost o~ the welding pro-cess~
There has also been proposed a method for vertical welding of aluminium (US Pat. No. 3,585,343) 9 w~ich includes establishing a slag bath o~ the ~ollowing compositio~ (in %):
potassium chloride . . . . . . . . . 45 sodium chloride . . ~ 27 s~dîum cryolite (~NaF.AlF~ . . . . 22 ( lithium chloride . . . . . . . . . 6, followed by ~using the electrode and the edges being weld joined and ~illing the gap betwee~ the edges with metal.
The above ~lux allows a stable electroslag welding process to be conducted, adequately deoxidizes an oxide ~ilm on the workpieces being weid-joined, but ~ails to en-sure sound welds unless the above-mentioned weld metal de-gassing techniques are resorted to~
The method contemplates the use o~ an apparatus com-prising a metal mould, graphite moulding shoes, current con-tact members, and a solid-section electrode with a guide bushing which provides ~or its rotation in the slag bath;
the current contact members are disposed outside the weld pool.
Degassing thé weld in the course of vJelding proceeds owing to the use of the graphite moulding shoes which re-duce the heat removal from the weld pool as well as to the electrode rotation in the slag bath~
Because of a h~gh rate of the weld metal crystalli-zation as well as o~ that the elec-trode rotation exerts 1 a mechanical ef~ect on the slag bath alone in the course of welding, this prior art method is incapable of fully degassing the weld metal~
The electroslag welding method with the use of the above-described flux and apparatus necessitates a complex follow-up equipment to ensure stabilit~ o~ the ~rocess thro-u~h controlling the electrode disposition in the weld pool~
which complicates the process, raises its cost, and still Yails to ~ully remove gases from the weld metal be~ore its crystallization because of a lo~ melting point o~ the flux.
The principal object of the present invention is to provide a method, a welding flux~ and an apparatus for electroslag welding of lig~ht metals and alLoys~ which en-sure a stable v~elding process and minimize the gas content in the weld metalO
An object of the invention, following from the pre-ceding one, is to provide a weldin~ f.lux whose quantitative and qualitative composition raises the heat capacity of the slag bath and thereby ensures the degassing of the liquid metal of the weld.
A further object of the invention is to widen the production possibilities of the method.
Still further object of the invention is to cut down the labour consumption of the welding process.
Yet further object of the inven-tion is to raise the productive capacity of the welding process.
An object of the invention is also to cut down the cost of production of weld joints.
Still another object of the invention is to provide an apparatus for electroslag welding, which ensures remo~-al of gases from the weld pool in the course of welding and self-regulation of the electrode fusion rate.
In accordance with a particular embodiment of the invention, there is provided a flux for the method of electroslag welding of light metals having the following composition (in wt.%):
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1~0 to 15Ø
This allows a weld joint with a sound weld metal to be obtained.
The slag bath heat capacity may be raised by increas-ing the bath volume. This slows down the rate of weld me-35~8 tal cooling in the course o~ welding.To raise the.slag bath he~t ca~acity a flu~ of the following composition (in %) is used:
barium fluoride . ~ . . . . . . 60.0 to 90.0 calcium ~luoride ~ . . . . . . . 5.0 to 15.0 lithium ~luoride . . . . . . . . 1~0 to 5~0 sodium fluoride . 0 . . . . ~ 0 to lOoO
potassium fluoride . . ~ . . . . 1.0 to 15,0 - I~corporation of barium fluoride in the above-speci-fied amounts into the proposed flu~ increases the flux density above that of the metal being ~elded~ and there-by facilitates separation of molten metal from slag in the course of electroslag welding as well as provides the sta-bility of the process.
Reducing the barium fluoride content in the propos-ed flu~ below the specified lower limit leads to a poor separation o~ molten metal ~rom slag in the process and impairs the stability of the latter, whereas e~ceeding the s~ecified upper limit reduces the activit~ o~ the flu~ and eventuallg results in weld de~ectsO
Incorporation of calcium fluoride in the above-spe-cified amounts into the composition of the proposed flux augments the activit~ of the latter and also, throu~h re-ducing the sur~ace tension at the slag-metal interface, pro-motes the merging of i~dividual liquid metal drops into one metal pool in the course of electroslag welding. Reduc-ing or increasing the calcium fluoride content in the pro-posed flux composition beyon~ the above-specified range s~
degrades the activity of the flu~.
Lithium, sodi~um, and potassium fluorides contained in the above-sPecified amounts in the composition of the proposed flux as well enhance its activit~.
The above-specified percentages of the flux compo-nents raise the flu~ melting point above -that of the metal being welded, which results in inhibiting the crystalliza-tion o~ the molten metal in the gap between the edges be~
ing weld-joined and hence in a higher degree of degassing the metal and in producing a sound wèld. ~he above advant-ages of -the proposed flux allow the qualit~ and operational dependability of welded joints to be greatly enhanced~
Increasing the heat ca~acity of the slag bath and holding the weld metal in a liquid state till its degass-ing in accordance with the proposed method are attained with the use of an apparatus which includes a metal mould with a bottom plate 7 moulding shoes, a current contact member, and a welding electrode, in which apparatus the welding electrode is installed through an aperture in the bottom plate centre and a lo~-resis-tance current contact member is installed in the electrode fusion zoneO
Such an arrangement provides for a stability of the v~elding process owing to a self-regulation of the v~elding electrode ~usion rate, since ~vhen the electrode end gets fused down below the top plane of the current contact mem-ber, the arc spot shifts from the electrode to the current lead member, thereby slo~ving do~n the electrode fusion rateO
The current contact member installed in the electrode ~usion zone may be made of either a solid material whose melting point exceeds the working temperature of welding or a liquid material whose boiling point e~ceeds the work-ing temperature of welding.
When thus selected, the current lead member material is not destructed i~ welding.
When a liquid material is chosen for the current con-tact member; the material is selected so that its density exceeds that of the slag bath and so that it neither mixes with ~or dissolves in the liquid electrode metalO
( Such a selection of the material precludes contamina tion of the weld metal with the CurreQt contact member ma-terial in the course of welding.
Preferable is such a modification of the electroslag welding apparatus wherein the electrode has internal pass-ages disposed along and across the electrode, ~illed with a gas-conducting material, and communicating with a simi-lar passage in the metal mould bottom plate.
The provision of such passages permits removal of gas-es from the weld pool ln the course of welding, while fill-ing the passages with a gas-conductin~ material prevents the weld pool from .~lowing out o~ the gap bet~een the edges being ~eld-.ioined~
The inven-tion will now be explained in greater de-tail with reference -to the accompanying drawings~ in which~
~ ig. 1 illustrates the process of electroslag welding of light metals and alloys according to the invention, with a solid c~rrent COQtact member;
~ ig. 2 illu~trates the same as ~ig. 1, but with a li-quid current contact member;
Fig. 3 illustrates the F~ocess of holding the liquid weld metal on a high-temperature hearth, after switGhin~
off the welding current; and ~ ig. 4 shows the obtained weld after crystallizatio~
~ ne invention is explained by way of specific ~xa-mples thereof~
E~ample 1 ~ lectroslag welding of workpieces vas carried out in an apparatus which was prepared for weldin~ b~ the ~ol-lowing procedure.
50~100-mm section9 500 m~ long aluminium sDecimens
2 to be welded together were placed on a metal mould 1 (Fig. 1) so that the gap between the edges to be weld-join-ed was of 60 mm; the specimens were insula-ted from the me-tal mould.
Graphite run-on plates 3 were installed on the spe-cimens 2. The gap between the edges to be weld-joined was closed at the sides by moulding shoes 4 insulated ~rom the specimens 2 to be welded.
An aluminium welding electrode 6, of 20x40 mm in secti-on, was inserted through an aperture in the centre of a bottom plate 5 into the gap between the edges to be weld-joined.
The aperture wherethrough the we~ding electrode 6 had been inserted was sealed v~ith an asbesto~ cord 7. Ne~t, a ~raphite current lead member 8 was installed around the 5~
welding electrode 6 and seal 7 on the bottom plate 5 in-side the metal mould 1~
The bottom plate 5 and the electrode 6 were provid-ed with internal passages 11, 129 13 for gases to escape from the weld pool in the course o~ ~eldi~g, the passages being filled with a mixture of a finely divided metallic material and a coarse-grained flux 14 to prevent the weld pool ~ro~ flowing out through the passages.
~ roceeding ~rom tne consideration that the melti~g point of the flux 14 ~or producing the bath must e~ceed that of the metal being welded (660C~9 the following flux composition was selected (in wt.%):
barium fluoride . 4 ~ 60.0 calcium fluoride . ~ . . . . . . l~oO
lithium ~luoride . . . . . ~ . . 5.0 sodium ~luoride . ~ . . .lOsO
potassium fluoride . . . . . . . . 10.0 ~ he density o~ the ~lux was o~ 3~1 g/cm3, and the melting point, of 900C.
The ~lux 14 so selected was filled into the gaP bet-ween the specimens 2 to be welded so that the top part o~
the welding electrode 6 was le~t exposed ~or 10 mm.
The run-on plates 3 and the welding electrode 6 were connected bg current feeding cables 15 to a welding trans-former 16.
Ne~t, a ~lux melted beforehand was poured over the flux 14 filled in the gap bet~een the edges -to be weld--joined.
~ he apparatus to accomplish the method ~or electro-slag welding of workpieces was thus prepared ~or operatiorl.
The welding conditions were as follows:
power source no-load voltage Url 1 = 38 Ys welding current Iw = 405 k~-Upon completion of the weldirlg circuit, the edges being weld-joined of the specimens 2 a~d the welding elect-rode 6 ~used; giving rise to a metal pool 17, while the flux melted and formed a slag bath 18; the metal pool 17 was protected ~rom the atmospheric effects by an inert gas, argon.
In the course of welding, the weldi~g electrode 6 fused down and filled the gap between the edges being weld-joined with metal until the ~used end of the welding electrode 6 had come to a positio~ below -the top face of the current lead member 8.
Such being the case, the fusion of the welding elect-rode 6 slowed down due to shifting of the arc spot from the electrode end to the -top face of the current contact memb-er 8; this in turn caused the electrode end to rise above the top face of the current contact member 8, i.e. a self-regulatiorl of the rate of fusion o~ the elec-trode 6 in the course o~ welding took place.
The gases evolved in the course of welding from the ~eld pool escaped via the passages 11, 12, 1~ of the weld-ing electrode 6 and the bot-tom plate 5~
hfber the gaP ~et-veen the ed~es being weld~joined o~ the sPecimens 2 got ~illed with the molten metal 17, -12_ t~e welding curre~t was switch2d off.
~ he slag bath 18 cr~stallized to ~orm a high-tem-perature hearth 19 with a temperature of 900C.
r~he temperature o e the hearth 19 and o~ the liquid metal 17 lowered from 900C to the crystallization tempe-rature o~ the metal 2 being we~ded, i.e. to 660C, in 1~5 min~ Over this time, the metal pool 17 remained liquid, which promoted the maxinum removal of gases from the ~eld metal. The weld metal de~assing took 1.2 min ~the metal pool degassing time was determined e~perimentally before the welding)~
After the li~uid metal had crysta~lized, a welded joint with a sound weld metal was obtained.
The weld metal strength ~as o~ 90-92% of that o~ the metal being welded, which e~ceeds similar characteristics for the prior art method.
The metallographic anal~sis demonstrated that the weld metal was free of pores~
The solid-material current contact member 8 may be substituted by a liquid-material current contact member 20 (Fig. 2). The welding process in the latter case i5 the same as in the above Example.
E~amples 29 3, 4, and 5 were similar in the proce-dure to Rxample l; the parameters ~or the ~xample~ are given in the Table below.
Electroslag welding in E~amples 2 and 3 yielded welded joints with a sound weld metal havin~ a strength of 90.0 and 75.0 %, res~ectively, of that O:e the metal be-in~ ~elded.
~ 5~
, ~able Mate- ~lect ~lux composition (in wt.%) ample being rode BaF2 CaF2 LiF ~aF K~
No. weld- rial ed ____________________________________________________ _____ 2 Titanium Titanium 90O0 5.0 2.0 2.0 1~0 ~ ~iagnesium ~agnesium 7500 lOoO 7~0 2~0 lOoO
4 Aluminium Aluminium 50.0 20.0 ~- 5.0 20.0 5 Aluminium Aluminium 95.0 2.0 1~5 1.0 005 ( ~ he metallographic analysis showed the weld metal to be free ~rom pores.
In ~xample 4, the weld metal contained crystallized slag iaclusions, which resulted ~rom a small dif~erence between the densities of the slag and the metal being weld-ed~
I~ E~ample 5, points of a poor ~usion of the weld metal with the edges bei~g weld-joined were observed, which stemmed ~rom an inadequate activit;y o~ the ~lux~
The Examples given above allow a conclusion to be drawn that electroslag welding in accordance with the pro-posed method with the use o~ the proposed flux composition and apparatus yields a sound weld metal featurin~ high me-chanical properties.
The E~amples given above do not restrict the range of metals being welded 9 since the method of the invention ~ith the use of the ~lux and apparatus of the invention .. .
will yield sound welded joints in welding metals whose densit~ is less than that o~ the weldin~ ~lux.
Graphite run-on plates 3 were installed on the spe-cimens 2. The gap between the edges to be weld-joined was closed at the sides by moulding shoes 4 insulated ~rom the specimens 2 to be welded.
An aluminium welding electrode 6, of 20x40 mm in secti-on, was inserted through an aperture in the centre of a bottom plate 5 into the gap between the edges to be weld-joined.
The aperture wherethrough the we~ding electrode 6 had been inserted was sealed v~ith an asbesto~ cord 7. Ne~t, a ~raphite current lead member 8 was installed around the 5~
welding electrode 6 and seal 7 on the bottom plate 5 in-side the metal mould 1~
The bottom plate 5 and the electrode 6 were provid-ed with internal passages 11, 129 13 for gases to escape from the weld pool in the course o~ ~eldi~g, the passages being filled with a mixture of a finely divided metallic material and a coarse-grained flux 14 to prevent the weld pool ~ro~ flowing out through the passages.
~ roceeding ~rom tne consideration that the melti~g point of the flux 14 ~or producing the bath must e~ceed that of the metal being welded (660C~9 the following flux composition was selected (in wt.%):
barium fluoride . 4 ~ 60.0 calcium fluoride . ~ . . . . . . l~oO
lithium ~luoride . . . . . ~ . . 5.0 sodium ~luoride . ~ . . .lOsO
potassium fluoride . . . . . . . . 10.0 ~ he density o~ the ~lux was o~ 3~1 g/cm3, and the melting point, of 900C.
The ~lux 14 so selected was filled into the gaP bet-ween the specimens 2 to be welded so that the top part o~
the welding electrode 6 was le~t exposed ~or 10 mm.
The run-on plates 3 and the welding electrode 6 were connected bg current feeding cables 15 to a welding trans-former 16.
Ne~t, a ~lux melted beforehand was poured over the flux 14 filled in the gap bet~een the edges -to be weld--joined.
~ he apparatus to accomplish the method ~or electro-slag welding of workpieces was thus prepared ~or operatiorl.
The welding conditions were as follows:
power source no-load voltage Url 1 = 38 Ys welding current Iw = 405 k~-Upon completion of the weldirlg circuit, the edges being weld-joined of the specimens 2 a~d the welding elect-rode 6 ~used; giving rise to a metal pool 17, while the flux melted and formed a slag bath 18; the metal pool 17 was protected ~rom the atmospheric effects by an inert gas, argon.
In the course of welding, the weldi~g electrode 6 fused down and filled the gap between the edges being weld-joined with metal until the ~used end of the welding electrode 6 had come to a positio~ below -the top face of the current lead member 8.
Such being the case, the fusion of the welding elect-rode 6 slowed down due to shifting of the arc spot from the electrode end to the -top face of the current contact memb-er 8; this in turn caused the electrode end to rise above the top face of the current contact member 8, i.e. a self-regulatiorl of the rate of fusion o~ the elec-trode 6 in the course o~ welding took place.
The gases evolved in the course of welding from the ~eld pool escaped via the passages 11, 12, 1~ of the weld-ing electrode 6 and the bot-tom plate 5~
hfber the gaP ~et-veen the ed~es being weld~joined o~ the sPecimens 2 got ~illed with the molten metal 17, -12_ t~e welding curre~t was switch2d off.
~ he slag bath 18 cr~stallized to ~orm a high-tem-perature hearth 19 with a temperature of 900C.
r~he temperature o e the hearth 19 and o~ the liquid metal 17 lowered from 900C to the crystallization tempe-rature o~ the metal 2 being we~ded, i.e. to 660C, in 1~5 min~ Over this time, the metal pool 17 remained liquid, which promoted the maxinum removal of gases from the ~eld metal. The weld metal de~assing took 1.2 min ~the metal pool degassing time was determined e~perimentally before the welding)~
After the li~uid metal had crysta~lized, a welded joint with a sound weld metal was obtained.
The weld metal strength ~as o~ 90-92% of that o~ the metal being welded, which e~ceeds similar characteristics for the prior art method.
The metallographic anal~sis demonstrated that the weld metal was free of pores~
The solid-material current contact member 8 may be substituted by a liquid-material current contact member 20 (Fig. 2). The welding process in the latter case i5 the same as in the above Example.
E~amples 29 3, 4, and 5 were similar in the proce-dure to Rxample l; the parameters ~or the ~xample~ are given in the Table below.
Electroslag welding in E~amples 2 and 3 yielded welded joints with a sound weld metal havin~ a strength of 90.0 and 75.0 %, res~ectively, of that O:e the metal be-in~ ~elded.
~ 5~
, ~able Mate- ~lect ~lux composition (in wt.%) ample being rode BaF2 CaF2 LiF ~aF K~
No. weld- rial ed ____________________________________________________ _____ 2 Titanium Titanium 90O0 5.0 2.0 2.0 1~0 ~ ~iagnesium ~agnesium 7500 lOoO 7~0 2~0 lOoO
4 Aluminium Aluminium 50.0 20.0 ~- 5.0 20.0 5 Aluminium Aluminium 95.0 2.0 1~5 1.0 005 ( ~ he metallographic analysis showed the weld metal to be free ~rom pores.
In ~xample 4, the weld metal contained crystallized slag iaclusions, which resulted ~rom a small dif~erence between the densities of the slag and the metal being weld-ed~
I~ E~ample 5, points of a poor ~usion of the weld metal with the edges bei~g weld-joined were observed, which stemmed ~rom an inadequate activit;y o~ the ~lux~
The Examples given above allow a conclusion to be drawn that electroslag welding in accordance with the pro-posed method with the use o~ the proposed flux composition and apparatus yields a sound weld metal featurin~ high me-chanical properties.
The E~amples given above do not restrict the range of metals being welded 9 since the method of the invention ~ith the use of the ~lux and apparatus of the invention .. .
will yield sound welded joints in welding metals whose densit~ is less than that o~ the weldin~ ~lux.
Claims
1. A flux to accomplish a method of electroslag welding of light metals and alloys, having the follow-ing composition (in wt.%):
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1.0 to 15Ø
barium fluoride . . . . . 60.0 to 90.0 calcium fluoride . . . . . 5.0 to 15.0 lithium fluoride . . . . . 1.0 to 5.0 sodium fluoride . . . . . 1.0 to 10.0 potassium fluoride . . . . . 1.0 to 15Ø
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/SU1980/000107 WO1982000016A1 (en) | 1980-06-26 | 1980-06-26 | Method,welding flux and device for electroslag welding |
| CA000363847A CA1162249A (en) | 1980-06-26 | 1980-11-03 | Method, welding flux, and apparatus for electroslag welding |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000363847A Division CA1162249A (en) | 1980-06-26 | 1980-11-03 | Method, welding flux, and apparatus for electroslag welding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1195218A true CA1195218A (en) | 1985-10-15 |
Family
ID=21616629
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000363847A Expired CA1162249A (en) | 1980-06-26 | 1980-11-03 | Method, welding flux, and apparatus for electroslag welding |
| CA000434337A Expired CA1195218A (en) | 1980-06-26 | 1983-08-10 | Welding flux |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000363847A Expired CA1162249A (en) | 1980-06-26 | 1980-11-03 | Method, welding flux, and apparatus for electroslag welding |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS58500111A (en) |
| AT (2) | AT375857B (en) |
| CA (2) | CA1162249A (en) |
| DE (1) | DE3050449C2 (en) |
| WO (1) | WO1982000016A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2802762A (en) * | 1953-08-19 | 1957-08-13 | Solar Aircraft Co | Welding fluxes |
| SU626913A1 (en) * | 1977-03-28 | 1978-10-05 | Ташкентский Политехнический Институт Имени А.Р.Беруни | Welding flux |
| SU764902A1 (en) * | 1977-06-06 | 1980-10-02 | Ордена Ленина И Ордена Трудового Красного Знамени Институт Электросварки Им. Е.О.Патона | Method of electroslag welding of light metals |
| SU935236A1 (en) * | 1978-07-12 | 1982-06-15 | Ордена Ленина И Ордена Трудового Красного Знамени Институт Электросварки Им.Е.О.Патона | Flux for electro-slag welding |
-
1980
- 1980-06-24 AT AT0915080A patent/AT375857B/en not_active IP Right Cessation
- 1980-06-26 WO PCT/SU1980/000107 patent/WO1982000016A1/en active Application Filing
- 1980-06-26 JP JP80501577A patent/JPS58500111A/en active Pending
- 1980-06-26 DE DE19803050449 patent/DE3050449C2/en not_active Expired
- 1980-11-03 CA CA000363847A patent/CA1162249A/en not_active Expired
-
1982
- 1982-06-24 AT AT0915080A patent/ATA915080A/en unknown
-
1983
- 1983-08-10 CA CA000434337A patent/CA1195218A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CA1162249A (en) | 1984-02-14 |
| DE3050449C2 (en) | 1987-10-29 |
| DE3050449T1 (en) | 1982-08-12 |
| WO1982000016A1 (en) | 1982-01-07 |
| AT375857B (en) | 1984-09-25 |
| JPS58500111A (en) | 1983-01-20 |
| ATA915080A (en) | 1984-02-15 |
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