Which increased risk occurred when Song Dynasty ironworkers cast early cannon barrels from a non-homogeneous mix?

💡 Explanation

Casting cannons using uneven iron compositions lead to differential cooling and expansion during firing; this thermal stress induces PRE-EXISTING CRACKS, because the material lacked uniform tensile strength; therefore weakening the structure rather than other fire-related consequences.

• Which outcome would excessively increase in Roman ballistae due to prolonged usage?
• Which outcome compromises Inca terracing when subsoil erosion overcomes the system's defenses?
• Which outcome occurs regarding a fortification wall when Roman cement's pozzolanic reaction slows significantly because lime source is impure?
• Increased bowstring slack occurs when humid conditions cause which mechanism in the composite crossbows used during the Han Dynasty?
• Which outcome results when Inca suspension bridge cables elongate?
• Which consequence results when seasonal temperature expansion biases astrolabe altitude readings in medieval navigation?