Years ago before the advance of modern steel cold weather can be more than nuissance It could actually end up in ship suddenly breaking up due to embrittlement case in point is librerty ship
Liberty Ship Design Flaws
Many early Liberty ships were affected by deck and hull cracks and indeed several were lost. About 1,200 ships suffered from cracks during the war (about 30% of all Liberty-class ships), and 3 were lost when the ship suddenly split in two. Though the work force was largely untrained in the method of welding ships together, it was not worker error that caused these failures. Rather, the failures were caused by a design oversight.
The cause of the failures was discovered by Constance Tipper, an engineering professor at Cambridge. She found that the grade of steel used to make Liberty ships suffered from embrittlement, in which materials become brittle. Ships operating in the North Atlantic were often exposed to temperatures below a critical temperature, which changed the failure mechanism from ductile to brittle. Because the hulls were welded together, the cracks could propagate across very large distances; this would not have been possible in riveted ships.
A crack stress concentrator contributed to many of the failures. Many of the cracks were nucleated at an edge where a weld was positioned next to a hatch; the edge of the crack and the weld itself both acted as crack concentrators. Also contributing to failures was heavy overloading of the ships, which increased the stress on the hull. Engineers applied several reinforcements to the ship hulls to arrest crack propagation and initiation problems.
you need to worry about ALL the facets of the alloy and the manufacturing process. To 99.9% of the population they look at the fan blades on their Airbus or 787s and think it's similar to their ceiling fans or the old school metal desk fan.
