Microstructural toughness
Microstructural toughness is the resistance of the crystal lattice and phase distribution to cracks on a microscopic level. It affects strength and behavior under mechanical loads.
Physico-chemical mechanism of action
Microstructural toughness depends on the arrangement and size of crystal grains in a metal. Smaller grains can absorb cracks better because they offer more surfaces for deformation.
Metallurgical relevance & risks in welding
A fine structure with small grains increases toughness and reduces the occurrence of cracks. If the grain size is too large or the phase distribution is uneven, toughness can decrease, which can lead to crack formation.
Workshop practice & instructions
To ensure high microstructural toughness, it is important to carry out the welding process under strictly controlled conditions. This includes the correct selection of the welding process, proper temperature control, and careful cooling. For steels with high carbon content, it is especially important to respect the critical temperature window (t8/5) to achieve a homogeneous structure.