TST – 28
Permissible spatial positions during welding
EA – 981/15 Welding Electrodes
Electrodes for welding high-alloy steels
Prices for welding electrodes
Type of coverage
Basic. (Low-hydrogen B).
Current and polarity
Direct current of reverse polarity (DC +, “plus” on the electrode). Welding is performed in all spatial positions except vertical “top-down”
Surfacing coefficient
10.00 – 11.0 g/ah
Consumption of electrodes
~ 1.5 kg per 1 kg of deposited metal
Application Area. TST – 28 Welding Electrodes.
TST-28 electrodes are intended for welding of equipment made of heat-resistant and high-temperature nickel-based alloys of grades KhN78T, KhN70VMYuT and similar, as well as dissimilar metals (pearlitic and chromium steels with nickel-based alloys). Welding in all spatial weld positions with direct current of reverse polarity.
Welding Technique. TST – 28 Welding Electrodes.
Welding with TST-28 electrodes is performed with a short arc on a surface cleaned of contaminants using narrow beads with a width not exceeding 2.5 times the electrode diameter. The process is carried out with direct current of reverse polarity (DC+) in all spatial positions, except vertical “top-to-bottom”. Craters must be filled during electrode short circuits.
Regulatory Documents. TST – 28 Welding Electrodes.
GOST 9466-75, GOST 9467-75.
Corresponding International Standard.
E – 000 – B20 (nickel type)
Main Weldable Materials. TST – 28 Welding Electrodes.
Welding of heat-resistant nickel alloys (KhN78T, KhN70VMYuT and similar). Welding of dissimilar joints (steel + nickel alloy). For operation at temperatures up to 1000°C and in aggressive environments.
Special Properties. TST – 28 Welding Electrodes.
High heat resistance: oxidation depth at 1000°C for 3000 hours — only 0.1 mm. High high-temperature strength: long-term strength of 100 MPa at 565°C for 10,000 hours. Metal structure — nickel solid solution with intermetallic precipitates.
Chemical Composition of Deposited Metal, %
| Ni | Si | Mn | P | S | Cr | C | Mo | W | |
| Minimum | Base up to 65% | < 0.50 | 1.50 | <0.020 | <0.018 | 12.50 | <0.10 | 13.50 | 3.50 |
| Maximum | Base up to 65% | < 0.50 | 2.50 | <0.020 | <0.018 | 15.50 | <0.10 | 16.00 | 4.50 |
Welding Recommendations (Current, A)
| Diameter, mm | Weld Position | ||
| Flat | Vertical | Overhead | |
| 3.0 | 80-120 | 70-100 | 70-100 |
| 4.0 | 130-160 | 120-150 | 120-150 |
We respond quickly to questions on Telegram
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Bottom horizontal or in a boat
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Bottom to the corner
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Horizontal seam on a vertical plane
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Vertical seam for lifting
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Vertical seam for descent
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Ceiling seam
All covered electrodes are sensitive to moisture absorption. Excessive moisture content in the coating can lead to porosity or hydrogen cracking.
However, if the climatic storage conditions meet the following requirements, moisture absorption by the electrodes is minimal:
• 5–15°C at a maximum relative humidity of 60%
• 15–25°C at a maximum relative humidity of 50%
• >25°C at a maximum relative humidity of 40%
At lower temperatures, maintaining the storage temperature 10°C above the ambient temperature is sufficient to achieve the required moisture content level. Cold packages must be allowed to warm up to ambient temperature before opening.
At higher temperatures, the required moisture content in the air can be achieved by dehumidification. The shelf life of electrodes under the above conditions shall not exceed three years.
• Covered electrodes with a basic coating and low hydrogen content must be baked prior to each use whenever requirements regarding the content of diffusible hydrogen and/or the soundness of the deposited metal are specified.
• Stainless steel electrodes with a basic coating may produce porosity during welding if the humidity levels during their storage did not meet the requirements. To restore their original properties, they also need to be baked.
• Electrodes for welding carbon steels with a cellulosic or rutile coating typically do not require baking.
• Electrodes that have suffered serious damage due to exposure to moisture cannot be restored by rebaking and must be rejected.
Contacts
Company phone numbers:
+375 (29) 688-27-06
+375 (17) 388-28-02 accountant
+375 (17) 388-28-03 sales department
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