Working principle of welding rod

I. Basic structure of welding rod

Welding rod is composed of welding core and protective coating. Welding core refers to the metal material that generates arc and conducts electricity during welding; protective coating refers to a layer of insulating material covering the surface of welding core, which is used to play the role of gas protection, oxidation prevention and filling material.

II. Working principle of welding rod

1. Melting process
   During the welding process, welding rod generates arc to heat the welding area to a melting temperature, generate molten pool, and connect the metal materials to be welded into one. During welding, the welding core will melt as the welding temperature rises, and the protective coating will gradually burn to produce beneficial gases, which can provide gas protection for the welding area.
2. Gas protection
   During welding, the protective coating of the welding rod can generate some gas during the melting process and protect the molten pool from oxidation and pollution of the air. These gases are usually carbon dioxide, argon, etc., which can prevent oxidation of the welding area and cause poor welding quality. The role of gas protection can also make the welding area more stable and the welding speed faster.
3. Filling material
   The protective coating of the welding rod also has a function as a filling material. During the welding process, the protective coating can be gradually released by burning and fill the weld; at the same time, the welding core itself can be melted into liquid and fill the weld. In this way, the gaps in the weld can be filled, the weld can be improved, and the inside of the weld can be made tighter.