Deoxidizer Pellet
Deoxidizer pellets bind dissolved oxygen, form insoluble oxides, and prevent porosity in the weld pool. This improves the cleanliness of the weld metal.
Physicochemical mechanism of action
Deoxidizer pellets are chemical additions that activate in the molten weld pool. They react with dissolved oxygen and form insoluble oxides that accumulate on the pellet surface. This process prevents oxygen from being absorbed into the metal crystals, thus avoiding porosity.
Metallurgical relevance & welding risks
Sufficient deoxidizer pellets are crucial for a clean and defect-free weld. Without or with too few pellets, oxygen can dissolve into the metal crystals, leading to porosity. These pores can affect the strength of the weld and lead to cracks. Additionally, too many pellets can over-enrich the weld metal with deoxidizer, which can impair its mechanical properties.
Workshop practice & instructions
For an optimal weld, it is important to add the right amount of deoxidizer pellets to the weld pool. This amount depends on the metal type and the desired structure. Typically, a certain percentage of the metal melt is used as pellets. For example, in steel welding, 0.5 to 1% of the melt can be added in the form of deoxidizer pellets. It is important to shake the pellets before adding and distribute them evenly in the weld pool. The temperature of the weld pool should be controlled during pellet addition to ensure an optimal reaction.