Low Cycle Fatigue Regime
The range at high plastic strains and low load cycles before the steel fails. Caused by thermal or mechanical cyclic deformation.
Physico-Chemical Mechanism of Action
In the low-cycle fatigue range, the material undergoes high plastic strain and alternates between different stress states. This leads to microscopic deformations that build up in the material.
Metallurgical Relevance & Risks in Welding
An excessive low-cycle fatigue range can lead to the development of microstructural defects and cracks. This increases the risk of fatigue failure and hot cracking. If handled incorrectly, the material may fail, causing damage and production downtime.
Workshop Practice & Instructions
To minimize the low-cycle fatigue range, ensure continuous cooling of the weld. Avoid rapid temperature changes and provide even cooling. For heavily loaded components, it is advisable to prefer stabilized steels or special welding processes.