Notch Effect
Notch effects increase mechanical stresses at cuts and fillets, leading to hardening and embrittlement and impairing toughness.
Physical-Chemical Mechanism of Action
Notch effect is a phenomenon where mechanical stresses are increased near cuts or fillets. These stresses can arise from mechanical loading, welding, or deformation.
Metallurgical Relevance & Welding Risks
The increased stress can lead to hardening of the material structure, especially if the material is cooled supercritically. This can lead to embrittlement and crack-sensitive martensite. The toughness of the material decreases, impairing the component's life and safety.
Shop Practice & Instructions
To minimize notch effects, ensure adequate cooling rate for the weld. The cooling shielding layer should be thinner than the material itself to allow uniform cooling. Avoid excessive cooling rates and pay attention to proper welding technique to reduce stresses at notches.