When can NDE of completed welds in ASTM A514 steels begin?

The correct answer is based on the understanding of the cooling and strengthening process of ASTM A514 steels. ASTM A514 is a high-strength, quenched and tempered alloy steel plate, and it is essential to allow adequate time for the welds to reach a stable condition before Non-Destructive Examination (NDE) is performed.

Welding generates a significant amount of heat, which can alter the mechanical properties of the steel. After welding, the metal must cool down adequately to ensure that any inspections reflect the true condition of the weldment. Performing NDE too soon can lead to misleading results as the weld might still be undergoing changes due to residual heat.

Waiting a minimum of 48 hours allows the welded joint to reach a stable temperature and enables the properties of the weld and the heat-affected zone to fully stabilize. This is critical for obtaining accurate NDE results and ensuring the integrity of the welds.

In contrast, the shorter time frames indicated in the other options do not provide sufficient time for the stresses generated during welding to dissipate and for the materials to stabilize. Therefore, performing NDE too soon can compromise the inspection's effectiveness and reliability.