Welding rod is a common welding material in welding, and sometimes it is found that the welding rod is not easy to use when using the welding rod, either the spatter is large, the arc is unstable, or the weld formation is poor.
In fact, this is the reason for the poor quality of the welding rod. How can we inspect the welding rod when we don’t have professional testing equipment?
Let me briefly introduce some simple methods for inspecting welding rods.
1. Simple method for inspection of welding rod quality
1. Inspection of actual welds
It is to inspect the quality of the welding rod by welding joint.
For high-quality welding rod, the arc combustion is stable during welding, the welding core and coating melt evenly, there is little splash, the weld joint is well-formed and the slag is easy to be removed.
2. Inspection of coating strength
Lift the electrode one meter high and fall freely on the smooth thick steel plate.
If the coating does not fall off, it is proved that the coating strength meets the quality requirements.
3. Appearance inspection
The coating surface shall be smooth and fine without pores and mechanical damage, the coating shall not be eccentric, and the welding core shall be free of corrosion.
4. Physical and chemical inspection
According to the requirements of engineering design, the chemical composition and mechanical properties of deposited metal shall be rechecked to inspect the quality of the welding rod.
2. Methods for identifying electrode deterioration
(1) Put several welding rods in the palm of your hand and roll them against each other.
If there is a clear metal sound, it is a dry welding rod. If there is a low rustling sound, it is a damp welding rod.
(2) Short circuit the electrode in the welding circuit for several seconds. If granular spots appear on the coating surface, it is a damp electrode.
(3) There are often rust marks on the welding core of the damp electrode.
(4) For the electrode with thick coating, bend it slowly to 120 °. If a large coating falls off or there is no crack on the coating surface, it is a damp electrode.
After light bending, the dry electrode has a small brittle crack sound, and continues to bend to 120 °, with a small crack on the side of the coating under tension.
(5) If the coating falls off in blocks or a large amount of water vapor is generated during welding, it indicates that it is a damp electrode.
If the coating falls off, the damp electrode shall be scrapped.
Although it is damp but not serious, it can be reused after drying.
Generally, the welding core of the welding rod has slight rust spots, which basically does not affect the use during welding, but the low hydrogen welding rod for important projects cannot be used after rust.