Hardening and Tempering. Steel can be treated by intense heat to give it different properties of hardness and softness. This depends on the amount of carbon in the steel (only high carbon steel can be hardened and tempered). CARBON CONTENT OF COMMON STEELS: Mild steel: 0.4% carbon, Medium carbon steel approximately 0.8% carbon, High Carbon Steel approximately 1.2% carbon (this steel is also known as Tool Steel and includes Silver Steel and Gauge Plate).
Mild steel and medium carbon steel do not have enough carbon to change their crystalline structure and consequently cannot be hardened and tempered. Medium carbon steel may become slightly tougher although it cannot be harden to the point where it cannot be filed or cut with a hacksaw (the classic test of whether steel has been hardened). If steel is heated until it glows red and is quenched in clean water immediately, it becomes very hard but also brittle. Temperature-Guide-to-Heat-Treating-Steel. Lucifer Furnaces Heat Treat Guide. The temperature you need to heat treat your material at will typically give you the answer: A FURNACE when you are above radiant heat (1300°F) and an OVEN with air recirculation when you are below. To maintain the utmost accuracy and extend the life of your heating elements, you should replace the thermocouples at least once a year. The sensing tips on the thermocouples degrade over time and begin to lose accuracy causing the heating element to work harder, shortening element life.
You should always have an extra heating element on hand to avoid unexpected downtime as well as the expense of overnight delivery. A protective atmosphere is used when exposure to air atmosphere may cause an undesirable chemical reaction with your parts. Note that if your parts are being cleaned or machined afterwards, the use of air atmosphere may be suitable. Both our GT and AM models are designed for use with inert protective atmospheres.