On 2018-08-08 14:48:54
Characteristics of heat treatment of die steel
(1) Materials and heat treatment die steel materials are annealed steel, Quenched and tempered steel, pre hardened steel, fully hardened steel and precipitation hardened steel, etc. Their machining processes are different.
① Such as chrome molybdenum steel. The hardness to be tempered is hrc30. Processing procedure: roughing → tempering → semi finishing → finishing.
② Use pre hardened steel. Sometimes the heat treatment does not reach the center of the steel plate, so heat treatment is carried out after rough machining.
③ To make precision molds (such as precision plastic molds, precision stamping molds, etc.) with fully hardened steel, the following sequence shall be followed. Rough machining → annealing stress relief → cutting → quenching → tempering → grinding electrical machining → mechanical finishing.
When the die parts are heat-treated, especially quenched, there will be different degrees of bending and deformation according to the shape of the parts, so annealing treatment is needed after processing to eliminate the residual stress. The precision of precision plastic mold parts is very high. If the internal stress is not eliminated, the deformation will occur after finishing.
(2) When the hardness of material is hrc40, it can still be milled. For quenched steel, it must be grinded, chipped or machined by electricity.