Grain Refinement Additive
Grain refiners are microscopic particles that act as nucleation sites and produce a fine-grained structure. This increases the toughness of the material.
Physical-Chemical Mechanism of Action
Grain refiners are small particles that are alloyed into the melt and act as nucleation sites during solidification. They influence grain formation and prevent the growth of large crystals.
Metallurgical Relevance & Risks in Welding
A fine-grained structure increases the toughness and dimensional stability of the material, which is especially important at high temperatures. Missing or insufficient use of grain refiners can lead to coarse grain formation, which reduces toughness and makes the material more susceptible to cracking.
Shop Practice & Operating Instructions
Use grain refiners in the right amounts, depending on the material and welding process. For high-carbon steels (e.g., HSS), 0.1 to 0.3% grain refiner is typical. Make sure the evaporation is correct and cooling is proper to achieve a homogeneous structure.