Function of the welding core

The welding core serves two purposes:

1. To conduct the welding current, generating an electric arc that converts electrical energy into heat.

2. The welding core itself melts and acts as filler metal, fusing with the molten base metal to form the weld. In electrode welding, the core metal constitutes a portion of the entire weld metal. Therefore, the chemical composition of the core directly affects the quality of the weld. Consequently, the steel wire used for the electrode core has its own specified grade and composition.

When used as filler metal in fusion welding methods such as submerged arc welding, electroslag welding, gas shielded welding, and oxy-fuel welding, it is called welding wire.

The electrode coating refers to the layer of material coated on the surface of the welding core. During the welding process, the coating decomposes and melts, forming gases and slag, which provide mechanical protection, metallurgical treatment, and improved process performance.

The components of the coating include: minerals (such as marble, fluorite, etc.), ferroalloys and metal powders (such as ferromanganese, ferrotitanium, etc.), organic substances (such as wood powder, starch, etc.), and chemical products (such as titanium dioxide, water glass, etc.). The electrode coating is a crucial factor in determining the quality of the weld.