Normalizing

Normalizing is done to make the structure uniform and fine-grained after welding or rolling. You heat the part to austenitizing temperature, let it soak briefly, and then cool in still air. This relieves stresses and makes the material workable and tough again. If you cool too fast, it becomes hard and brittle; if too slow, the grain becomes coarse. So make sure the part cools evenly and is not in a draft.