CA1041384A - Method for producing moisture resistant electrodes - Google Patents
Method for producing moisture resistant electrodesInfo
- Publication number
- CA1041384A CA1041384A CA203,374A CA203374A CA1041384A CA 1041384 A CA1041384 A CA 1041384A CA 203374 A CA203374 A CA 203374A CA 1041384 A CA1041384 A CA 1041384A
- Authority
- CA
- Canada
- Prior art keywords
- electrode
- low
- electrodes
- silica
- hydrogen type
- 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
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
- B23K35/404—Coated rods; Coated electrodes
-
- 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
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
- B23K35/0261—Rods, electrodes, wires
- B23K35/0272—Rods, electrodes, wires with more than one layer of coating or sheathing material
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Nonmetallic Welding Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
METHOD FOR PRODUCING MOISTURE RESISTANT ELECTRODES
ABSTRACT OF INVENTION
A method of making flux-covered welding electrodes which are resistant to moisture absorption wherein untreated covered electrodes are treated with a dilute aqueous dispersion of at least one material taken from the class of silicon bearing materials con-sisting of colloidal amorphous solid silicas, quarternary ammonium colloidal silica sols and soluble silicates of lithium and po-tassium.
S P E C I F I C A T I O N S
ABSTRACT OF INVENTION
A method of making flux-covered welding electrodes which are resistant to moisture absorption wherein untreated covered electrodes are treated with a dilute aqueous dispersion of at least one material taken from the class of silicon bearing materials con-sisting of colloidal amorphous solid silicas, quarternary ammonium colloidal silica sols and soluble silicates of lithium and po-tassium.
S P E C I F I C A T I O N S
Description
3~ ~
- This invention relates to moisture resistant covered electrodes and more particularly to a method ~or producing such moisture resistant electrodes.
Covered electrodes, sometimes also referred to as stick electrodes, are manufactured to specific moisture levels. Broadly speaking there are two classes of such covered electrodes. The first class is the low-hydrogen type, used herein to mean electrodes such as low-hydrogen, low-alloy low-hydrogen or stainless steel electrodes. This class is manufactured to and supplied at :Low contained moisture levels (less than 0.6% by weight of the flux coating). These electrodes are usually supplied in hermetically sealed containers. The second class is the non-low-hydrogen class, used herein to include all other welding electrodes such as cellu-losic, titania and iron oxide. Thls class is manufactured to and supplied at contained moisture levels from 0.6 to,5.0% by wèight of the flux coating. - -Once electrodes of either type are exposed to the atmos- , phere, they seek to e~uilibrate their contained mois,ture level with the moisture contained in the atmosphere. Variations of moisture level is undesirable. In the case of low-hydrogen electrodes, once a package of electrodes is opened the electrodes must be stored in a holding oven at temperatures in excess of 100C or significant moisture absorption will occur~ This moisture is transferred to the arc during welding and results in a weld deposit susceptible to ', hydrogen cracking. If electrodes are exposed to moisture they can ;; ' be reconditioned by baking at about 455C for about one (1) hour. ,~' ,` ,' The necessity for such reconditioning of exposed electrodes is ~' ~1 ~
expensive. Use of exposed electrodes can result in defective weld .
.
.. . . . . . . .
,;.. . ~ . : . , D-92~9 ~tal. Accordingly, the development of a method for improving the moisture resistance of low-hydrogen type electrodes is of considerable commercial importance~ Non-low-hydrogen electrodes are not used in conditions of high restraint where susceptibility to hydrogen cracking i9 important. These electrodes are designed to operate with some contained moisture content in the coating.
However, these electrodes do not operate well if their moisture content is allowed to vary significantly. Accordingly, the de-velopment of a method for improving the control of moisture in non-low-hydrogen type electrodes is of considerable commercial importance.
It is therefore the object of this invention to provide a method for producing moisture resistant covered electrodes of the low-hydrogen type. It is a further object to provide a method for insuring control of moisture in covered electrodes of the non-low-hydrogen type.
These and other objects will either be pointed out or become apparent from the following description and drawings wherein Figures 1-6 are curves showing moisture adsorption for commercial prepared electrodes treated by the method of the invention.
It is theorized that moisture absorption in covered elec-trode coatings is due to the physical absorption of water by pores.
These pores exist as a result of incomplete densification of the coating during manufacture. It has been discovered that if elec-trodes of the low-hydrogen type are treated with a dilute aqueous dispersion of at least one material taken from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates of
- This invention relates to moisture resistant covered electrodes and more particularly to a method ~or producing such moisture resistant electrodes.
Covered electrodes, sometimes also referred to as stick electrodes, are manufactured to specific moisture levels. Broadly speaking there are two classes of such covered electrodes. The first class is the low-hydrogen type, used herein to mean electrodes such as low-hydrogen, low-alloy low-hydrogen or stainless steel electrodes. This class is manufactured to and supplied at :Low contained moisture levels (less than 0.6% by weight of the flux coating). These electrodes are usually supplied in hermetically sealed containers. The second class is the non-low-hydrogen class, used herein to include all other welding electrodes such as cellu-losic, titania and iron oxide. Thls class is manufactured to and supplied at contained moisture levels from 0.6 to,5.0% by wèight of the flux coating. - -Once electrodes of either type are exposed to the atmos- , phere, they seek to e~uilibrate their contained mois,ture level with the moisture contained in the atmosphere. Variations of moisture level is undesirable. In the case of low-hydrogen electrodes, once a package of electrodes is opened the electrodes must be stored in a holding oven at temperatures in excess of 100C or significant moisture absorption will occur~ This moisture is transferred to the arc during welding and results in a weld deposit susceptible to ', hydrogen cracking. If electrodes are exposed to moisture they can ;; ' be reconditioned by baking at about 455C for about one (1) hour. ,~' ,` ,' The necessity for such reconditioning of exposed electrodes is ~' ~1 ~
expensive. Use of exposed electrodes can result in defective weld .
.
.. . . . . . . .
,;.. . ~ . : . , D-92~9 ~tal. Accordingly, the development of a method for improving the moisture resistance of low-hydrogen type electrodes is of considerable commercial importance~ Non-low-hydrogen electrodes are not used in conditions of high restraint where susceptibility to hydrogen cracking i9 important. These electrodes are designed to operate with some contained moisture content in the coating.
However, these electrodes do not operate well if their moisture content is allowed to vary significantly. Accordingly, the de-velopment of a method for improving the control of moisture in non-low-hydrogen type electrodes is of considerable commercial importance.
It is therefore the object of this invention to provide a method for producing moisture resistant covered electrodes of the low-hydrogen type. It is a further object to provide a method for insuring control of moisture in covered electrodes of the non-low-hydrogen type.
These and other objects will either be pointed out or become apparent from the following description and drawings wherein Figures 1-6 are curves showing moisture adsorption for commercial prepared electrodes treated by the method of the invention.
It is theorized that moisture absorption in covered elec-trode coatings is due to the physical absorption of water by pores.
These pores exist as a result of incomplete densification of the coating during manufacture. It has been discovered that if elec-trodes of the low-hydrogen type are treated with a dilute aqueous dispersion of at least one material taken from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates of
-2-~289 lithium and potassium in the manner hereinafter described, theresistance of the coatings to moisture absorptlon is remarkably increased and can, in fact, approach totality. Similarly, it has been discovered that if electrodes of the non-low-hydrogen type are so treated, the mDisture content of the coatings can be controlled more closely thereby insuring more uniform operability.
It is postulated that the phenomenon responsible for the production of moisture resistance in the treated electrodes , . .
is related to the formation of a film on the electrode coating~s surface. This film fills the surface pores of the untreated - electrode, thereby preventing moisture from being absorbed. In a similar manner, this film prevents moisture from being desorbed and can be used to control the quantity of moisture in the coating o a non-low-hydrogen electrode.
Because the phenomenon ~s thought to be related to film formation, it was believed that any material capable of i forming a film would be effective. However, it has been found that the objects of the invention are achieved when the treating dispersions are made from colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates of lithium and potassium. It has been found that soluble silicates '!
.;. , ~ . .
of sodium produce no improvement in moisture control in the electrode coating. Colloidal amorphous solid silicas preferably having an ultimate particle size of less than one (1) micrometer are such materials as fumed silicas, chemically precipitated silicas and silicas preci~itated from silica sols. Quaternary a~monium colloidal -silica sols have a weight ratio SiO2/(NR4)20 of 0.18/1.0 to 9.0/1Ø Soluble silicates of lithium have a weight ratio SiO2/Li20 of 9.4/1.0 to 17.0/1Ø Soluble silicates of potassium '''J 30 have a weight ratio SiO2/~ 0 of 1.8/1.0 to 2.5/1Ø The weight percent of SiO2 in the silicates of both lithium and potassium can . .
be readily calculated from the weight ratios indicated above.
~ In the case of silicates of lithium, SiO2 is present in a range of ., : .
~ -3-` 9289 .
38~: `
from about 90 to ~5% by weight. In the case of silicates of potassium, SiO2 is present in a range of from about 64 to 72%
by weight.
In practice, commercially prepared low-hydrogen type electrodes were taken and soaked in an aqueous dispersion made from at least one material from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates ; of lithium and potassium. The electrodes were then dried to ` 10 drive off any contained water. Speci~ically, electrodes were soaked in a dispersion of lithium silicate ~weight ratio SiO2/Li2O of 9.5/1.0 for one (1) hour at room temperature (25C)).
The dispersion contained 6% by weight SiO2. After soaking, the electrodes were dried at 455C for one (1) hour.
Other treatments were made on commercially prepared , low-hyrdogen and non-low-hyd~ogen electrodes. These treatments were variations of the one given above. For instance, an aqueous - dispersion made with a colloidal amorphous solid silica with 2%
by weight SiO2 was used. In general, successful treatments have been made with dispersions containing from about 1% to about 20%
by weight SiO2. Similarly, the treatment temperature may be varied between about 5 and about 95C and treatment times from about (1~ minute to five (5) hours. Preferably, the dispersion will contain clos2 to 6% by weight SiO2. Preferred treatment conditions are 65C and one (1) hour. The film may be applied ~ by soaking, brushing or spraying. In some cases brushing or j-l spraying will be more desirable.' The ~ormation of the surface film is accomplished by ~i 30 mass transport of the silica/silicate through the solvent. According-ly, time, temperature, solution concentration and solution agi~ation may be expected to affect the resultant moisture resistance. The film must be uniform. If the solution concentration is too high, .
flaky patches appear on the electrode coating. If the concentration ~...... . . . . . . ... .
: ~43L~384 ;
is too low, inordinate amounts of time are required to achieve `~
- filming. Solution stirring or agitation helps insure a uniform ` coating. The rate of uptake at the surface increases with increa~sing temperature. The maximum temperature is limited by -~
..
precipitation of the silica/silicate from solu~ion. Time of treatment affects only the ultimate magnitude of the uptake.
i Moisture absorption data for commercially prepared electrodes treated in the manner described above, soluble r. silicate o~ lithium (weight ratio Sio2¦Li2O of 9.5.1.0), one (1) hour at 25C, are shown in Figures 1 through 5. The data were taken at 100% relative humidity and 25C. Data identified by 1 are the un~reated commercial electrode performances; data identi~ied by 2 are the treated perEormances. Moisture absorp- ~ ;
tion is plotted both ~8 totàl weight gain in grams and a % weight gain for the coating. The electrodes tested are representative ~'1 of the ~ollowing American Welding Society classifications: -Figure 1, E7018 low-hydrogen electrode; Figure 2, E7014 celluloslc; ~-electrode; Figure 3~ EI2018 low-alloy, low-hydrogen electrode;
Figure 4, E308-15 stainless electrode; and Figure 5, E308-16 stainless electrode.
Welding tests were performed to compare the behaviour ~ of electrodes. Two electrodes of the E7018 type, one treated - in the preferred manner and one ~mtreated, were exposed to 100% RH
' 1 ~
:
. ., ~ ' .
... .
.. . . ..... . . . ..
It is postulated that the phenomenon responsible for the production of moisture resistance in the treated electrodes , . .
is related to the formation of a film on the electrode coating~s surface. This film fills the surface pores of the untreated - electrode, thereby preventing moisture from being absorbed. In a similar manner, this film prevents moisture from being desorbed and can be used to control the quantity of moisture in the coating o a non-low-hydrogen electrode.
Because the phenomenon ~s thought to be related to film formation, it was believed that any material capable of i forming a film would be effective. However, it has been found that the objects of the invention are achieved when the treating dispersions are made from colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates of lithium and potassium. It has been found that soluble silicates '!
.;. , ~ . .
of sodium produce no improvement in moisture control in the electrode coating. Colloidal amorphous solid silicas preferably having an ultimate particle size of less than one (1) micrometer are such materials as fumed silicas, chemically precipitated silicas and silicas preci~itated from silica sols. Quaternary a~monium colloidal -silica sols have a weight ratio SiO2/(NR4)20 of 0.18/1.0 to 9.0/1Ø Soluble silicates of lithium have a weight ratio SiO2/Li20 of 9.4/1.0 to 17.0/1Ø Soluble silicates of potassium '''J 30 have a weight ratio SiO2/~ 0 of 1.8/1.0 to 2.5/1Ø The weight percent of SiO2 in the silicates of both lithium and potassium can . .
be readily calculated from the weight ratios indicated above.
~ In the case of silicates of lithium, SiO2 is present in a range of ., : .
~ -3-` 9289 .
38~: `
from about 90 to ~5% by weight. In the case of silicates of potassium, SiO2 is present in a range of from about 64 to 72%
by weight.
In practice, commercially prepared low-hydrogen type electrodes were taken and soaked in an aqueous dispersion made from at least one material from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols and soluble silicates ; of lithium and potassium. The electrodes were then dried to ` 10 drive off any contained water. Speci~ically, electrodes were soaked in a dispersion of lithium silicate ~weight ratio SiO2/Li2O of 9.5/1.0 for one (1) hour at room temperature (25C)).
The dispersion contained 6% by weight SiO2. After soaking, the electrodes were dried at 455C for one (1) hour.
Other treatments were made on commercially prepared , low-hyrdogen and non-low-hyd~ogen electrodes. These treatments were variations of the one given above. For instance, an aqueous - dispersion made with a colloidal amorphous solid silica with 2%
by weight SiO2 was used. In general, successful treatments have been made with dispersions containing from about 1% to about 20%
by weight SiO2. Similarly, the treatment temperature may be varied between about 5 and about 95C and treatment times from about (1~ minute to five (5) hours. Preferably, the dispersion will contain clos2 to 6% by weight SiO2. Preferred treatment conditions are 65C and one (1) hour. The film may be applied ~ by soaking, brushing or spraying. In some cases brushing or j-l spraying will be more desirable.' The ~ormation of the surface film is accomplished by ~i 30 mass transport of the silica/silicate through the solvent. According-ly, time, temperature, solution concentration and solution agi~ation may be expected to affect the resultant moisture resistance. The film must be uniform. If the solution concentration is too high, .
flaky patches appear on the electrode coating. If the concentration ~...... . . . . . . ... .
: ~43L~384 ;
is too low, inordinate amounts of time are required to achieve `~
- filming. Solution stirring or agitation helps insure a uniform ` coating. The rate of uptake at the surface increases with increa~sing temperature. The maximum temperature is limited by -~
..
precipitation of the silica/silicate from solu~ion. Time of treatment affects only the ultimate magnitude of the uptake.
i Moisture absorption data for commercially prepared electrodes treated in the manner described above, soluble r. silicate o~ lithium (weight ratio Sio2¦Li2O of 9.5.1.0), one (1) hour at 25C, are shown in Figures 1 through 5. The data were taken at 100% relative humidity and 25C. Data identified by 1 are the un~reated commercial electrode performances; data identi~ied by 2 are the treated perEormances. Moisture absorp- ~ ;
tion is plotted both ~8 totàl weight gain in grams and a % weight gain for the coating. The electrodes tested are representative ~'1 of the ~ollowing American Welding Society classifications: -Figure 1, E7018 low-hydrogen electrode; Figure 2, E7014 celluloslc; ~-electrode; Figure 3~ EI2018 low-alloy, low-hydrogen electrode;
Figure 4, E308-15 stainless electrode; and Figure 5, E308-16 stainless electrode.
Welding tests were performed to compare the behaviour ~ of electrodes. Two electrodes of the E7018 type, one treated - in the preferred manner and one ~mtreated, were exposed to 100% RH
' 1 ~
:
. ., ~ ' .
... .
.. . . ..... . . . ..
3~4 40C for four (4) hours. In this time the treated electrode coating absorbed 0.07 g of moisture. The untreated electrode coating absorbed 0.20 g of moisture. When th~ two types of electrodes were used in welding using identical conditions in a circular patch cracking test, the weld made with the treated electrode was free from microcracks and slag entrapment while the weld made with the untreated electrode had a high incidence of microcracks and slag entrapment. In another test, two electrodes of the E9018 type, one treated in the preferred manner and one untreated, were ex-. ,.
10 posed to 100% RH and 40C for two ~2) hours. The treated electrode coating absorbed 0.04 g of moisture. The untreated electrode coating absorbed 0.12 g. When the two types were used in welding in a con-strained fillet test uncler identical conditions, the treated electrode produced a sound weld while the untreated electrode produced a weld ,l with underbead cracking.
The comparative effects of 5 soluble silicate treatments, 2 sodium, 2 potassium and 1 lithium, on the moisture absorption i characteristics of an E308-16 stainless electrode are shown in Figure 6~ All dispersions were prepared to 6~/o by weight SiO2 and all treatment steps were identical. In comparing the results to the untreated electrode, note that, in order o decreasing effectiveness, the treatments were: lithium (SiO2/Li20 of 9.5/1.0 by weight), po-tassium ~SiO2/K20 of 2~5/1~0 by weight), sodium (SiO2/Na20 of 3~2/1.0 ~j! by weight) and sodium (SiO2/Na20 of 2.0/1~0 by weight). The lithium treatment was very effective; the sodium treatments were not at all effective.
In actual practice the treatment of this invention may be applied to electrodes which have been made and stored or it may be ' ,, .
a lied to electrodes as they are being made in the first instance.
However, in order for the treatemnt to be effective in the latter case, some type of drying treatment should be made to the electrode between extrusion of the coating on~o the metal core and the treatment of this invention.
Also, it is possible to perform the treabment of this invention in two steps. Each treatment step being of a shorter duration than one long treatment step. Generally, if the treatment is performed in two steps, moisture resistance is superior to the 10 moisture resistance achieved by one treatment step of temporal length equal to the two treatment steps.
The surface of the treated electrodes were examined using ' a Scanning Electron Microscope and an Energy Dispersive X-ray Analyzer. The film or layer on the coated electrode analyzed was significantly richer in silicon than the bulk coating. In the case of electrodes treated with a dispersion of soluble silicate of lithium (weight ratio SiO2/Li20 of 9.5/1.0), the film had a composition of about 20% Li; 27% Si; and 53% 0 by weight and was J about one (1) micrometer in thickness. When the electrodes are i~ 20 treated with a dispersion of a colloidal amorphous solid silica, the film is significantly richer in silicon than the bulk coating. In this case, the layer composition is about 47% Si, 53% 0.
Having described the invention with reference to certain preferred embodiments, it should be obvious that minor modifications can be made to the dispersion recited or to the method of making and/or applying same to the covered electrodes without departing from the spirit and scope of the invention.
.. .. .
. .
' :; . :. . .
10 posed to 100% RH and 40C for two ~2) hours. The treated electrode coating absorbed 0.04 g of moisture. The untreated electrode coating absorbed 0.12 g. When the two types were used in welding in a con-strained fillet test uncler identical conditions, the treated electrode produced a sound weld while the untreated electrode produced a weld ,l with underbead cracking.
The comparative effects of 5 soluble silicate treatments, 2 sodium, 2 potassium and 1 lithium, on the moisture absorption i characteristics of an E308-16 stainless electrode are shown in Figure 6~ All dispersions were prepared to 6~/o by weight SiO2 and all treatment steps were identical. In comparing the results to the untreated electrode, note that, in order o decreasing effectiveness, the treatments were: lithium (SiO2/Li20 of 9.5/1.0 by weight), po-tassium ~SiO2/K20 of 2~5/1~0 by weight), sodium (SiO2/Na20 of 3~2/1.0 ~j! by weight) and sodium (SiO2/Na20 of 2.0/1~0 by weight). The lithium treatment was very effective; the sodium treatments were not at all effective.
In actual practice the treatment of this invention may be applied to electrodes which have been made and stored or it may be ' ,, .
a lied to electrodes as they are being made in the first instance.
However, in order for the treatemnt to be effective in the latter case, some type of drying treatment should be made to the electrode between extrusion of the coating on~o the metal core and the treatment of this invention.
Also, it is possible to perform the treabment of this invention in two steps. Each treatment step being of a shorter duration than one long treatment step. Generally, if the treatment is performed in two steps, moisture resistance is superior to the 10 moisture resistance achieved by one treatment step of temporal length equal to the two treatment steps.
The surface of the treated electrodes were examined using ' a Scanning Electron Microscope and an Energy Dispersive X-ray Analyzer. The film or layer on the coated electrode analyzed was significantly richer in silicon than the bulk coating. In the case of electrodes treated with a dispersion of soluble silicate of lithium (weight ratio SiO2/Li20 of 9.5/1.0), the film had a composition of about 20% Li; 27% Si; and 53% 0 by weight and was J about one (1) micrometer in thickness. When the electrodes are i~ 20 treated with a dispersion of a colloidal amorphous solid silica, the film is significantly richer in silicon than the bulk coating. In this case, the layer composition is about 47% Si, 53% 0.
Having described the invention with reference to certain preferred embodiments, it should be obvious that minor modifications can be made to the dispersion recited or to the method of making and/or applying same to the covered electrodes without departing from the spirit and scope of the invention.
.. .. .
. .
' :; . :. . .
Claims (10)
1. A method for treating covered electrodes to make them moisture resistant, comprising; dispersing at least one material taken from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols, and soluble silicates of lithium and potassium, in water until the silica concentration is from about 1 to 20% by weight and applying such solution to said covered electrode for a period of from about 1 minute to about 5 hours at a temperature of from about 5° to 95°C
followed by a suitable drying operation to remove water.
followed by a suitable drying operation to remove water.
2. Method according to claim 1 wherein said covered electrode is of the low hydrogen type.
3. Method according to claim 1 wherein said covered electrode is of the non-low-hydrogen type.
4. A method for treating low-hydrogen type electrodes to make them moisture resistant, comprising; dispersing lithium silicate having a weight ratio SiO2/Li2O of 9.5/1.0 in a liquid until the silica concentration is 6% by weight silica and applying such solution to a low-hydrogen type electrode for a period of 60 minutes at a temperature of 65°C and then drying such electrode to remove water.
5. A method for treating low-hydrogen type electrodes to make them moisture resistant, comprising; dispersing a colloidal amorphous silica sol in water until the silica concentration is 6%
by weight silica and applying such solution to a low-hydrogen type electrode for a period of 60 minutes at a temperature of 65°C and then drying such electrode to remove water.
by weight silica and applying such solution to a low-hydrogen type electrode for a period of 60 minutes at a temperature of 65°C and then drying such electrode to remove water.
6. A method for treating low-hydrogen type electrodes to make them moisture resistant, comprising; dispersing precipitated silica in water until the silica concentration is 2% by weight silica and applying such solution to a low-hydrogen type electrode for a period of 60 minutes at a temperature of 65°C and then drying such electrode to remove water.
7. A moisture resistant covered electrode comprising a metal core, a flux coating on said core and a moisture resistant thin film on the outer surface of such flux coating, said film containing at least one material taken from the class of silicon bearing materials consisting of collodial amorphous solid silicas, and silicates of lithium and potassium, the silica content of said film being at least 64% by weight; the moisture resistance of such covered electrode being improved by a factor of two over an electrode without said film.
8. Electrode according to claim 7 wherein the electrode is a low hydrogen type.
9. Electrode according to claim 7 wherein the electrode is a non-low hydrogen type.
10. A method for treating non-low-hydrogen electrodes to control the amount of moisture in their coatings, comprising dispersing at least one material taken from the class of silicon bearing materials consisting of colloidal amorphous solid silicas, quaternary ammonium colloidal silica sols, and soluble silicates of lithium and potassium, in water until the silica concentration is from about 1 to 20%
by weight and applying such solution to a non-low-hydrogen type electrode for a period of from about 1 minute to about 5 hours at a temperature of from about 5° to 95°C and then drying said electrode to remove water.
by weight and applying such solution to a non-low-hydrogen type electrode for a period of from about 1 minute to about 5 hours at a temperature of from about 5° to 95°C and then drying said electrode to remove water.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37991773A | 1973-07-17 | 1973-07-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1041384A true CA1041384A (en) | 1978-10-31 |
Family
ID=23499225
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA203,374A Expired CA1041384A (en) | 1973-07-17 | 1974-06-25 | Method for producing moisture resistant electrodes |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5234258B2 (en) |
| BR (1) | BR7405824D0 (en) |
| CA (1) | CA1041384A (en) |
| ES (1) | ES428304A1 (en) |
| FR (1) | FR2237721B1 (en) |
| GB (1) | GB1470404A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56112044A (en) * | 1980-02-07 | 1981-09-04 | Matsushita Electronics Corp | Manufacture of tubular bulb |
| JPS59131022U (en) * | 1983-02-21 | 1984-09-03 | 日本エンヂニヤ−・サ−ビス株式会社 | Float type liquid level gauge |
| PL3266560T3 (en) * | 2016-07-05 | 2019-08-30 | Ductil S.A. | Multi-coated electrode for welding stainless steel |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3392039A (en) * | 1964-12-17 | 1968-07-09 | Philadelphia Quartz Company Of | Lithium silicate composition |
-
1974
- 1974-06-25 CA CA203,374A patent/CA1041384A/en not_active Expired
- 1974-07-16 JP JP49080817A patent/JPS5234258B2/ja not_active Expired
- 1974-07-16 ES ES428304A patent/ES428304A1/en not_active Expired
- 1974-07-16 FR FR7424686A patent/FR2237721B1/fr not_active Expired
- 1974-07-16 GB GB3138274A patent/GB1470404A/en not_active Expired
- 1974-07-16 BR BR582474A patent/BR7405824D0/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5039246A (en) | 1975-04-11 |
| ES428304A1 (en) | 1976-07-16 |
| GB1470404A (en) | 1977-04-14 |
| BR7405824D0 (en) | 1975-05-13 |
| DE2434190A1 (en) | 1975-02-13 |
| DE2434190B2 (en) | 1976-12-30 |
| FR2237721A1 (en) | 1975-02-14 |
| FR2237721B1 (en) | 1980-03-28 |
| JPS5234258B2 (en) | 1977-09-02 |
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