TC Industries Mill Products Division is the industry leader for process annealing
Process annealing, or sub-critical annealing, involves heating steel to a particular temperature just below the austenitic transformation temperature followed by a slow cool. Process Annealing is used to improve machinability, reduce internal stresses, and when considerable cold working is to follow. The Annealing process differs from Quench and Temper where the metal is heated to just above the austenitic transformation temperature to impart a high degree of hardness.
The Mill Products Division is equipped with an annealing furnace that has a hot zone of eighty feet in length. It is an open fired continuous roller hearth furnace. There is no protective atmosphere. The subsequent zone is approximately one hundred feet, providing a slow furnace cool. This furnace can accommodate bars up to thirty nine feet in length.
The annealing cycle that we use provides a mill anneal, or an anneal for machinability. This process typically results in mixed microstructures containing various amounts of lamellar pearlite and some small fraction of spherodite. This process cannot provide an LP or Lamellar-Pearlitic anneal.