Niobium carbide precipitation
The targeted precipitation of fine niobium carbides during thermomechanical processing, which effectively blocks grain growth. This achieves significant grain refinement hardening in the steel microstructure.
Niobium is an important alloying element in fine-grained structural steels. It forms finely distributed carbides that suppress grain growth during rolling and heat treatment. This gives you a fine microstructure with good strength and toughness. When welding, you must be careful that the heat input is not too high. Otherwise, the carbides dissolve again and the grain grows. Cooling should be controlled so that the niobium carbides can precipitate finely again. Pay attention to the material specifications from the manufacturer, as the niobium content varies greatly depending on the grade. With incorrect heat management, the notch impact work in the vicinity can drop.