The impact of moist electrodes on welding quality, and how to identify moist electrodes

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1) Weld cracks and pores are generated. The water absorbed by the wet welding electrode turns into gas under the heat of the welding arc, releasing hydrogen, which causes welding cracks and pores to form. This is especially true for alkaline electrodes. Sealing welding rods in polyethylene plastic bags does not guarantee complete moisture protection over the long term. 2) All mechanical property indicators are on the low side. Simple methods for on-site inspection of whether electrodes are damp: 1) Check the packaging of the electrodes; if the packaging is damaged, the electrodes are likely to be severely damp. 2) Check the manufacturing date of the welding rod; welding rods that have been stored for a long time after production are prone to developing white, mold-like spots on their surface. 3) Roll a few electrodes in your hand; electrodes that have absorbed moisture lose their crisp metallic sound. 4) Take a welding rod and bend it slightly by 10-15 degrees; if a distinct cracking sound is heard during the bending, it indicates that the rod is relatively dry. 5) Place a welding rod vertically on the ground and observe its bouncing ability; dry welding rods have better bouncing capacity and a higher rebound. 6) Connect the welding rod to the welding circuit for a few seconds in a short-circuit condition; if water vapor appears on the surface of the coating, it indicates that the welding rod is not dry. 7) Take a welding rod and conduct a trial weld. If the rod is damp, the flux will crack or peel off in chunks during welding, and a large amount of water vapor will be generated. 8) Inspect the surface at the end of the welding core to check for rust. 9) Take a bundle of electrodes and inspect it with the naked eye: if there are black spots on the surface of the coating, it indicates that the core inside the electrode has rusted. The coating can also be knocked off to directly check whether the welding core is corroded.   10) During welding operations, it has been observed that the process properties of wetted electrodes undergo the following changes: ● At the same current level, the arc blow force increases and the penetration depth increases ； ● The amount of splashing increases, and the particles grow larger ； ● For acidic electrodes, the slag coverage is poor and the weld shape is inferior ； ● In low-hydrogen electrodes, many small pores appear on the inner surface of the slag (the side in contact with the weld). Determination of the valid period for welding materials: ★ According to JB3223-96 \"Procedures for Quality Management of Welding Materials\", the valid period is determined starting from the date of production using the following method: 1) The period recommended in the quality certificate or instruction manual for the welding materials ； 2) Acidic welding materials and low-hydrogen welding materials with well-sealed moisture-proof packaging have a shelf life of two years ； 3) Graphite-type welding materials and other welding materials are one year. ☆ Welding electrodes, fluxes, and cored wires that have exceeded the specified validity period must pass retesting in accordance with the regulations before they can be issued for use.