Notch toughness is on requirements for some structural applications especially those in seismic areas. What does notch toughness do?

• A. Increases corrosion resistance
• B. Welds with high notch toughness have greater resistance to cracking due to rapidly applied loads.
• C. Improves weld appearance
• D. Increases heat input

Answer: (B)

Notch toughness describes a material’s ability to resist fracture when there’s a flaw or notch, especially under sudden, dynamic or impact-like loading. In seismic or other rapidly applied loads, stress concentrates at notches, so a weld with high notch toughness can absorb more energy and slow or prevent crack growth instead of failing catastrophically. That’s why the statement saying welds with high notch toughness have greater resistance to cracking under rapidly applied loads is the best answer.

Not about corrosion resistance, which is chemical in nature; nor about how the weld looks, which is a surface issue; nor about heat input, which relates to how the weld is made rather than the material’s resistance to crack under dynamic loads.