Constitution of Undercooled Melts
The constitution of undercooled melts describes the interaction of elements and phases in the liquid before it solidifies into metal. A fine crystallization process promotes a homogeneous structure.
Physico-chemical mechanism of action
The constitution of undercooled melts refers to the composition and state of the liquid before it crystallizes into solid metal. Elements such as silicon or carbon play a decisive role in deoxidation and crystallization rate.
Metallurgical relevance & risks during welding
A fine-grained crystallization of undercooled melts leads to a homogeneous and stable structure that offers higher strength and toughness. However, an unequal constitution state can lead to imbalances in composition, which can cause porosity or hot cracking in the metal.
Workshop practice & instructions
To ensure an optimal constitution of undercooled melts, the melting temperature and cooling time should be precisely controlled. In steel welding, it is important to control the heat transfer from the liquid to the solid state to achieve a fine-grained structure. This can be achieved by selecting the appropriate shielding gas and correct cooling regulation.