1. Welding cracks and pores are generated. The moisture absorbed by the electrode is changed into gas under the action of welding arc heat, and hydrogen is decomposed, resulting in the formation of welding cracks and pores. Especially alkaline electrodes. When the welding rod is packaged with polyethylene plastic bags, it cannot guarantee long-term complete moisture resistance.
2.The indexes of mechanical properties are low.
A simple way to check the wet condition of the electrode on site:
(1) Check the packaging of the welding rod, the packaging is damaged, and the moisture absorption of the welding rod must be serious.
(2) Check the date of manufacture of the electrode, and the surface of the electrode that has been stored for a long time after manufacture is prone to white mildew-like spots.(3) Roll a few electrodes in your hands, and the electrodes lose their crisp metallic sound after absorbing moisture.
(4) Take a welding rod and bend it slightly by 10-15 degrees. If there is an obvious brittle sound when bending, it means that the welding rod is relatively dry.
(5) Take a welding rod to the ground and observe its bouncing force. The dry electrode has better bouncing force and higher rebound.
(6) Connect the electrode to the welding circuit and short-circuit it for a few seconds. If there is water vapor on the surface of the coating, it is a non-dry electrode.
(7) Take an electrode for test welding directly. If the electrode is wet, the coating will burst or the coating will fall off in pieces during the welding process, and more water vapor will be generated.
(8) Observe the surface of the end of the welding core to see if there is rust.
(9) Take a bunch of electrodes and check with the naked eye: if there are black spots on the surface of the coating, it means that the welding core inside the electrode has been corroded. You can also knock off the coating and directly check whether the solder core is corroded.
(10) Check during the welding operation that the following changes will occur in the process properties of the wet electrode:
●At the same current value, the arc blowing force becomes larger and the penetration depth increases;
The number of splashes increases and the particles become larger;
● For acid electrodes, the slag coverage is poor, and the weld formation becomes poor;
● For low-hydrogen electrodes, there are many small holes on the inner surface of the slag (the side in contact with the weld).
