List the welds in order of crack susceptibility.

List the welds in order of crack susceptibility.

• A. Fillet, Groove, Tack, Plug, Hole Repair
• B. Groove, Tack, Fillet, Hole Repair, Plug
• C. Groove, Fillet, Tack, Plug, Hole Repair
• D. Groove, Fillet, Hole Repair, Tack, Plug

Answer: (C)

Crack susceptibility in welded joints follows how heat input and geometry create restraint and stress concentrations. The most prone are deep, highly restrained groove welds used in butt joints; they have pronounced toes and roots where residual tensile stresses concentrate and hydrogen-related cracking can initiate under cyclic loading. Fillet welds, with their smoother transitions and shallower penetration, introduce less restraint and fewer sharp stress risers, so they are less likely to crack. Tack welds are very small, temporary welds used to hold pieces in place; because of their limited size and localized heating, they contribute far less to crack initiation than larger welds. Among repair welds, plugging a hole concentrates stress at the edge of the hole, making it more susceptible than a repair that surrounds a hole and distributes heat more evenly. Therefore, the order from most to least crack-susceptible aligns with groove welds first, followed by fillet welds, then tack welds, then plug welds, and finally hole repair welds as the least susceptible.

Crack susceptibility in welded joints follows how heat input and geometry create restraint and stress concentrations. The most prone are deep, highly restrained groove welds used in butt joints; they have pronounced toes and roots where residual tensile stresses concentrate and hydrogen-related cracking can initiate under cyclic loading. Fillet welds, with their smoother transitions and shallower penetration, introduce less restraint and fewer sharp stress risers, so they are less likely to crack. Tack welds are very small, temporary welds used to hold pieces in place; because of their limited size and localized heating, they contribute far less to crack initiation than larger welds. Among repair welds, plugging a hole concentrates stress at the edge of the hole, making it more susceptible than a repair that surrounds a hole and distributes heat more evenly. Therefore, the order from most to least crack-susceptible aligns with groove welds first, followed by fillet welds, then tack welds, then plug welds, and finally hole repair welds as the least susceptible.