Season cracking is spontaneous cracking which occurs on exposure to atmospheric corrosion in brass objects with high residual tensile stresses at the surface. It occurs with high-zinc brasses but rarely with 15 per cent zinc or below. Alloys susceptible to spontaneous season cracking will crack when exposed to corrosive conditions under high service stress, even if they are free from internal strains. Season cracking can be prevented by avoiding the production of internal microstresses or by removing such stresses by relief annealing at 245 to 275°C without softening the work.
Alloys containing more than 80% copper are highly resistant to season cracking.