Fatigue Limit
The fatigue limit is the maximum stress value below which a material can withstand an infinite number of load cycles. It separates the finite life region from the infinite life region.
Physical-Chemical Mechanism of Action
The fatigue limit describes the stress value below which a material can withstand infinite load cycles without cracking. This value depends on the microstructure and mechanical properties of the material.
Metallurgical Relevance & Risks in Welding
If the stress during operation exceeds the fatigue limit, the material can gradually crack. This leads to a reduced service life and possibly fractures. In welded joints, it is especially important that the stress range stays below this limit to ensure a safe and durable connection.
Workshop Practice & Action Instructions
To respect the fatigue limit, it is crucial that the stress range during operation stays below the maximum allowable value. This can be achieved by careful material selection and optimal component design. In welded joints, stress concentration should be minimized by choosing a suitable welding process and properly assembling the joint.