Micro-Crack Network
A microcrack network consists of very small cracks that spread through the material structure. It often arises from thermal overload or corrosion and can impair the strength of the material.
Physico-chemical Mechanism of Action
A microcrack network forms when very small cracks appear in a material and spread slowly. These cracks can be caused by thermal stresses or chemical reactions such as corrosion.
Metallurgical Relevance & Risks in Welding
A microcrack network can seriously impair the mechanical strength of a material. It leads to reduced toughness and increases susceptibility to larger cracks or fractures. In the weld zone, it can form due to insufficient cooling or chemical reactions, making the material dangerous.
Workshop Practice & Instructions
To avoid microcrack networks, careful cooling of the weld is essential. The cooling rate should be set so that the material does not cool too quickly (which leads to glass-hard martensite) and not too slowly (which leads to grain coarsening and loss of toughness). Correct selection of welding material and processes, as well as regular inspection for corrosion damage, are also crucial.