L&L Special Furnace Co. Inc. manufactured a high-uniformity box furnace to be used for hydrogen annealing. The furnace, which has a work envelope measuring work envelope of 17 inches wide x 17 inches high x 25 inches deep, has been delivered to a manufacturer of aerospace, medical, and research and development supplies. The primary purpose of the furnace is to evenly heat to an internal stabilized temperature of 1750°F (955°C). The furnace is held at this temperature for a predetermined amount of time and then cooled using an external venturi cooling system.
A Honeywell HC900 control system includes a CPU and operator interface with Ethernet capabilities. Modular construction makes the HC900 expandable, with several input and output options. The HC900 software monitors and logs all of the thermal data from a remote computer. The furnace is divided into six zones, each with independent PID loops. The thermocouples are type K and allow for consistent operation at 1750°F.
Steel hydrogen annealing softens metals and simultaneously changes the properties of the metal, improving machinability, facilitation of cold-work, mechanical and electrical properties, and stability of dimensions.