solution heat treatment

A type of heat treatment in which the metal is heated in a furnace until its temperature is uniform throughout. It is then removed from the furnace and quenched in cold water. When the metal is hot, the alloying elements enter into a solid solution with the base metal to become part of its basic structure. When the metal is quenched, the alloying elements remain a part of the base-metal structure. If the metal is not immediately quenched after it is removed from the furnace, some of the alloying elements will precipitate, or settle out, of the solid solution with the base metal, and the grain structure will enlarge. The metal will not be as strong as it would have been if it were properly quenched, and intergranular corrosion is likely to form along the enlarged grain boundaries.