What are the annealing processes for cast iron used in outdoor flower boxes?

Cast iron is a popular material for outdoor flower boxes due to its strength and classic aesthetic. However, to ensure longevity and prevent cracking, annealing—a heat treatment process—is often applied. The annealing process for cast iron involves heating the metal to a specific temperature (typically between 900°C and 950°C) and then cooling it slowly in a controlled environment. This relieves internal stresses, improves ductility, and reduces brittleness, making the flower boxes more resistant to outdoor conditions like temperature fluctuations and moisture. Different types of annealing, such as full annealing and stress relief annealing, may be used depending on the cast iron's composition and intended use. Proper annealing ensures that cast iron flower boxes remain durable and visually appealing for years.