David Pye's series on normalizing forged aerospace components concludes with part 5.

We continue our discussion of normalizing.

The next question to be asked is, "How do we cool after normalizing?" The generally accepted method of cooling is to “cool in still air and free from drafts.” While this is a general statement and a generally accepted practice, it does not ensure a repeatable and consistent final metallurgy.

The normalizing process is generally applied to unalloyed steels or low-alloy (hypoeutectoid) steels (i.e., steels with a carbon content lower than 0.77%). Normalizing is applied to hypereutectoid steels (i.e., steels with a carbon content greater 0.77%) only in special cases.  

L&L Special Furnace Co. Inc. shipped a large gas-fired normalizing furnace to a manufacturer of pipe, tube and fittings used for military contracts. The furnace, which has work dimensions of 48 inches wide x 48 inches high x 120 inches deep, is rated to operate at temperatures of 1300-2200°F (704-1204°C) and is heated with six medium-velocity burners. It will be able to maintain uniformity of ±25°F (±12.5°C) at temperatures above 1300°F (704°C). The car-bottom-style furnace features a load car that moves in and out of the unit on supplied railroad-type rails. The door is mounted to the car, which is motorized with all required stops and clearances. The side seals are pneumatic and seal to the car bottom once the car is inside the furnace. Castable piers provide support for loads up to 10,000 pounds. The furnace is insulated with ceramic-fiber modules.

The forging of a steel component to arrive at a rough shape prior to machining is a procedure that has been adopted almost from the time that man discovered iron. Forging is a not only an ancient craft, it is a science in the manipulation of steel into a predetermined shape that is roughly the final shape of the component to be manufactured.

L&L Special Furnace Company received an order for a car-bottom furnace from a manufacturer of pipes, tubes and fittings located in the southeastern United States. The gas-fired furnace, scheduled for delivery in the fourth quarter of 2021, will be used for normalizing various steels and specialty alloys at temperatures up to 2200°F (1200°C). It will also be used to preheat, stress relieve and temper various steels and large pipe fittings. Working dimensions are 48 inches wide x 48 inches high x 120 inches deep, and uniformity of ±25°F (12.5°C) or better is expected throughout the work zone.

Z Capital Partners, the private-equity fund management arm of Z Capital Group (ZCG), entered into a definitive agreement to sell Premier Thermal Solutions LLC (PTS), a provider of metal-processing services, to an affiliate of Aalberts N.V. The deal is expected to close before the end of the year. PTS provides commercial metal-processing services to a variety of industries, including aerospace, defense, automotive, heavy truck, energy, heavy equipment and other industrial end markets. Since opening its first plant in Lansing, Mich., in 1978, the company has expanded to 10 plants across the Midwest.

Lindberg/MPH shipped two gas-fired hardening and tempering furnaces to the manufacturing industry. The large-capacity box furnaces will be used for the normalizing, austenitizing and tempering of forged components. The furnaces can accept a maximum load measuring 6 feet wide x 6 feet deep x 6 feet high, and the actual chamber is larger to provide clearance for parts. The outer-shell sidewalls and floor are constructed from 3/16-inch steel plate. The lining is ceramic-fiber modules that store low amounts of heat and have superior insulating qualities to provide maximum fuel efficiency.

Can-Eng Furnaces International Ltd. has been awarded a contract by a major U.S. automotive parts supplier for the complete overhaul and refurbishment of a cast link-belt normalizing furnace. Designed and manufactured by Can-Eng in 1996, the equipment was originally rated at 27,000 pounds/hour of hot-charged, closed-die forgings. It was known to be one of the largest cast link-belt furnaces in the world at the time of its manufacture. The refurbishment project will take place in Can-Eng’s Niagara Falls shops and will consist of a complete refractory reline, new combustion system, new control panel and a Level II automation system.