Shielded Metal Arc Welding (SMAW) Process

Shielded Metal Arc Welding (SMAW) Process

1. Welding Process

2. Heating Characteristics of SMAW

(1) High heating temperature and localized heating. The metal near the weld is heated very unevenly, which may cause workpiece deformation, residual stress, and uneven changes in microstructure and properties.

(2) Fast heating rate (1500 degrees/second), uneven temperature distribution, which may lead to microstructures and defects that should not appear in heat treatment.

(3) The heat source is mobile, and the heating and cooling areas are constantly changing.

III. Metallurgical Characteristics of Arc Welding

(1) High temperature in the reaction zone causes strong evaporation and oxidation of alloying elements.

(2) Small molten metal pool volume and short liquid time result in uniform chemical composition. Gases and impurities do not have time to float to the surface, easily leading to defects such as porosity and slag inclusions.