Which forging outcome occurred during Ming Dynasty cast-iron cannon firing?

💡 Explanation

Iron weakens because cyclical thermal stress caused metal fatigue, a slow accumulation of micro-cracks rather than immediate bursting. Therefore, tensile strength failed, due to repeated heating and cooling rather than boosted conductivity.

• Which outcome occurs in a Boulton-Watt steam engine when the condenser cooling water supply is interrupted?
• Which risk increases during prolonged, intense rainfall on steeply terraced agricultural land in the pre-Columbian Andes?
• Which outcome occurs when differential thermal expansion stresses Incan masonry?
• Which risk increases when a sailing ship alters course without recalculating position via celestial navigation?
• Which control-system consequence appears during periods of high Inca bridge maintenance demands, signaled by complex quipu recordings?
• Which increased consequence faced early rope bridge builders?