Monotectoid Reaction
Monotectoid reaction: A phase transformation where a solid phase splits into two different solid phases. Example: the splitting of carbon into graphite and diamond.
Physico-chemical mechanism of action
In a monotectoid reaction, a solid phase splits into two different solid phases, often under the influence of temperature or pressure. This process resembles the monotectic liquid separation, where a liquid phase splits into two different liquid phases.
Metallurgical relevance & risks in welding
In welding technology, the monotectoid reaction can cause issues when the structure of a steel splits into different phases under certain conditions. This can affect hardness and mechanical properties and cause cracks.
Workshop practice & instructions
To avoid monotectoid reactions, it is important to precisely control welding parameters like temperature and pressure. For steels with high carbon content, hardening can be reduced by careful cooling. For special materials or complex components, it is advisable to have the welding processes monitored by an experienced metallurgist.