Hardened and tempered process
Hardening and Tempering is a thermal process that strengthens steel through a controlled heating and cooling process Hardened andtempered steel strip is used in many applications includingsaws,cutting tools, packing strap,wiper blade as well as flat springs.
This process will result in improved mechanical properties and give a tougher more durable product. The hardening process involves heatingthe steel to above the critical transformation temperature for the given grade and then rapidly cooling. Whilst this process achieves the highest mechanical strengths and hardness's, steel in this condition is extremely brittle and therefore requires further treatment in the form of tempering. This consists of reheating the steel to a lower temperature and holding the steel at the given temperature for a given period of time. As with traditional annealing (used to soften steels) this process is conducted in an inert atmosphere to avoid oxidation .The exact temperatures and processing times vary with given grades of steel and the process is very specialised.Below is the production line of hardenning and tempering.