Globular precipitates

Globular precipitates are round particles in the microstructure that form during cooling or heat treatment. Their round shape distributes stresses better and can improve mechanical properties. But if they become too large or too numerous, they coarsen the structure and make the steel tougher and less crack-sensitive – you don't want that. When welding, you need to control the cooling. Too fast cooling leads to martensite, which is hard and crack-prone. For higher carbon steels, that means: cool slowly and controlled so the structure can settle evenly. The right cooling rate depends on the material – you have to follow the data sheet, not some blanket value.