TC Industries Mill Products Division is the industry leader for quench and tempering
The first step in the quench-and-temper process is to heat the material to a uniform temperature above the austenitic transformation temperature, usually about 1650º F. The hot metal is then quenched in a liquid, usually oil (for medium carbon plate or alloy plate like 1060, 4155, or 4350) or water (for plain carbon grades like 1018 or low alloy grades like 4140). The rapid cooling transforms a portion of the material to a martensitic microstructure, imparting a very high degree of hardness. The Quench and Temper process differs from Annealing where the metal is heated to just below the austenitic transformation temperature to improve machinability.
As-quenched, the metal is too brittle to be used, and is returned to a furnace for another cycle, this time at a lower temperature that will reduce or temper the hardness and restore some ductility.
The final surface hardness that can be achieved in this process is dependent on the chemical content of the steel. The chemistry also dictates the hardening depth and the ultimate mechanical properties that can be expected.
The Mill Products Division has the capability to quench and temper carbon and alloy steel bars in water or oil. We can process round bars in diameters from 7/16 inches to 14 inches. We can also heat treat flats and squares as thin as 1/8 inch in thickness and up to 72 inches in width. We can process tubes ranging in diameters of 5/8" to 21”. Depending on the size and grade of the bar, we can handle lengths up to 53 feet.
All of our high temperature furnaces are gas-fired roller hearth furnaces. They are direct-fired into the furnace chamber. Most of what we heat treat is in the hot-rolled or as-rolled condition, but that is not a requirement.
All of our tempering furnaces are continuous gas-fired recirculating furnaces. After bars are quenched, they are placed on the entrance table of the tempering furnace. At this point the bars begin to travel the full length of the furnace. Every inch of every bar passes through the entire length of the furnace. This assures that the bars are evenly tempered and that the hardness is uniform throughout the length of the bar. Temperature uniformity surveys are regularly conducted on each furnace to verify process controls.