Alternating fatigue limit
Fatigue strength is the maximum stress a material can withstand under repeated tensile and compressive cycling without failing.
Physical-Chemical Mechanism of Action
Fatigue strength describes a material's resistance to repeated stress cycles. With each cycle between tensile and compressive stress, microscopic cracks form in the material, increasing with each cycle until they lead to complete failure.
Metallurgical Relevance & Risks in Welding
A low fatigue strength value can lead to premature failure of components under load cycles. This is particularly relevant in machine components or bridge construction, where repeated loading is common. A value that is too low can also lead to cracking and corrosion problems.
Workshop Practice & Instructions
To improve the fatigue strength of a material, you can:
• Use higher stress or temperature during welding
• Apply special welding methods such as TIG welding
• Choose a material with better fatigue strength
• Perform post-weld treatments such as normalizing or tempering