Fatigue Crack Growth Rate
The fatigue crack growth rate describes how fast a crack grows in a material under repeated loading. The higher the rate, the faster the material breaks.
Physico-chemical mechanism of action
The fatigue crack growth rate is a measure of the increase in crack length per load cycle under cyclic loading. It depends on the swing of the stress intensity factor, which indicates the maximum stress relative to the material's limit stress.
Metallurgical relevance & risks in welding
A too high fatigue crack growth rate leads to rapid crack growth and increases the susceptibility to fatigue fractures. This can lead to component failure and safety problems in service.
Workshop practice & action instructions
To minimize the fatigue crack growth rate, it is important to select and treat the material correctly. This includes appropriate hardening treatment and careful welding. When selecting the material, properties such as final hardness and toughness should be considered.