How to distinguish between welding slag and molten iron during welding?

During the welding process, the welder can see a layer of covering floating on the surface of the molten pool, which is commonly known as welding slag. How to distinguish between welding slag and molten iron is very important for welders who are new to electric welding.

1. Formation of welding slag

Welding slag is the product of the melting of the electrode coating and the high-temperature metallurgical reaction of the weld. Welding slag is mainly composed of metal oxides or non-metal oxides and other mineral salts. Because its density is higher than the density of liquid iron during welding, Much smaller, therefore, the welder can easily observe a layer of floating matter on the upper part of the molten pool during the welding process. In terms of color, it is darker than the liquid iron in the molten pool, and is opposite to the welding direction. It flows in the direction and rear sides, cools as welding continues, and becomes welding slag.

2. The role of welding slag

Welding slag mainly protects the weld bead during the welding process. The liquid metal in the molten pool is covered by the slag to separate the liquid metal and the air and prevent the intrusion of harmful gases such as oxygen, nitrogen, and hydrogen in the air. To protect the weld bead. Therefore, during the welding process, we must pay attention to the welding angle to ensure that the welding slag flows to the rear and rear sides, so as to observe the shape of the weld and avoid the occurrence of defects such as slag inclusions and pores. Ensure welding quality