SCH8O/DIN Welding Rod

Welding rod storage and moisture-proof management: How to avoid hydrogen-induced cracks and process failure?

1. What problems will the damp welding rod cause?
Once the welding rod coating absorbs moisture, the water decomposes under the high temperature of welding to produce hydrogen, which may lead to serious consequences:
Hydrogen-induced cracks (cold cracks): Hydrogen atoms penetrate into the weld metal and form cracks at the stress concentration point when cooling, which is common in high-strength steel and thick plate welding.
Weld pores: Water evaporates to form bubbles, resulting in pore defects inside or on the surface of the weld.
Abnormal welding process: Wet welding rods are prone to arc instability, increased spatter, insufficient penetration and other problems.

2. How to store welding rods correctly?
The core of welding rod storage is moisture-proof, temperature control and sealing:

Unopened welding rods:
Store in a dry and ventilated warehouse with humidity controlled below 60% and temperature maintained at 10~25℃.
Avoid direct contact with the ground or wall. It is recommended to use shelves to raise the height by more than 30cm.
The original packaging should be sealed and stored in accordance with the "first in, first out" principle to avoid long-term backlog.

Opened welding rods:
Welding rods that have not been used up in the short term should be temporarily stored in a constant temperature drying oven (100~150℃).
Low hydrogen welding rods (such as E7018) are sensitive to humidity. It is recommended to use them within 4 hours after opening, and shortened to 2 hours in high humidity environments.

3. Key points of welding rod drying
The drying requirements of different welding rods vary greatly:
Cellulose welding rods (such as E6010): Usually no drying is required, but strict moisture protection is required. If slightly damp, they can be dried at low temperature (60~80℃) for 0.5~1 hour.
Low hydrogen welding rods (such as E7018): They must be dried at high temperature (300~350℃) for 1~2 hours to completely remove moisture from the coating.
Stainless steel welding rods: The drying temperature is relatively low (150~250℃), and the heat preservation is sufficient for 1 hour, and the exposure time can be relaxed to 8 hours.

Note:
The dried welding rod should be stored in an insulation bucket (100~150℃) and taken out as needed.
The welding rod should not be dried multiple times, generally not more than 3 times, otherwise the coating will crack and fall off easily.

4. Moisture-proof measures at the welding site
Environmental control: When the humidity in the welding area exceeds 80%, the operation should be suspended or dehumidifiers, heaters and other equipment should be used to improve the environment.
Welding rod carrying management: welders need to be equipped with portable insulation buckets to ensure that the welding rods are kept dry before use.
Emergency treatment: Slightly damp welding rods can be used after secondary drying, but if the coating has obviously fallen off or agglomerated, it must be scrapped.

5. How to prevent hydrogen-induced cracks?
Preheating before welding: For high carbon steel, alloy steel or thick plates, preheating before welding (80~200℃) can reduce the cooling rate and reduce hydrogen accumulation.
Post-weld dehydrogenation treatment: Immediately heat to 250~300℃ after welding, keep warm for 2~6 hours to promote hydrogen diffusion and escape.
Choose low-hydrogen welding materials: Preferentially use low-hydrogen electrodes (such as E7018) or low-hydrogen welding processes (such as TIG welding) to reduce hydrogen content from the source.