ANS:C - brasses.

Season cracking is a form of stress corrosion failure that is generally observed in brasses. Season cracking, also known as stress corrosion cracking (SCC) or season cracking corrosion, is a specific type of corrosion failure that occurs when a material is subjected to tensile stress in the presence of a corrosive environment. This phenomenon is particularly common in certain alloys, including brasses. Brasses are copper-zinc alloys, often with small amounts of other elements added for specific properties. They are commonly used in various applications due to their excellent combination of strength, corrosion resistance, and machinability. However, certain brass compositions are susceptible to season cracking under specific conditions. Season cracking in brasses typically occurs when the material is exposed to a corrosive environment, such as ammonia-containing atmospheres or certain aqueous solutions, while simultaneously being subjected to tensile stress. The presence of the corrosive environment weakens the material's resistance to stress corrosion, leading to the initiation and propagation of cracks under applied tensile stress. The term "season cracking" originates from the observation that this type of failure often occurs during specific seasons or periods of the year when environmental conditions, such as humidity or temperature, are conducive to corrosion. In summary, season cracking is a form of stress corrosion failure commonly observed in brasses when they are subjected to tensile stress in the presence of a corrosive environment. This phenomenon highlights the importance of material selection, design considerations, and environmental control in preventing stress corrosion failures in engineering applications.