During the heat treatment, precision molds often deformed, in order to prevent this negative phenomenon, as long as we grasp its deformation law, analyze its causes, using different methods can prevent deformation of the mold is reduced, but also be able to controlling. In general, sophisticated molds heat deformation may take the following methods to prevent.
(1) reasonable selection. For sophisticated molds should choose a good micro-deformation of steel material (such as air quenching steels), for carbide segregation serious casting mold steel should be fair and transfer of heat treatment, and can not be larger steel casting mold can be solution bis refinement heat treatment.
(2) die structure design to be fair, not too poor thickness, shape to be symmetrical, large deformation for mold to grasp the deformation law, set aside allowance for large, sophisticated molds can be combined structure.
(3) sophisticated molds to pre-heat treatment to eliminate residual stress generated during machining.
(4) a reasonable selection heating temperature control heating rate, for sophisticated molds can be taken to slow heating, pre-heating and other methods to reduce the mold uniform heating heat deformation.
(5) in ensuring the mold hardness conditions, maximize the use of pre-cooling, grading cooling or quenching temperature quenching process.
(6) for sophisticated molds, in the case of conditions permit, try using cryogenic vacuum heating process and hardening after quenching.
(7) for some sophisticated molds can pre-heat treatment, aging heat treatment, quenching and nitriding to control the accuracy of the mold.
(8) at the time of repair mold blisters, porosity, wear and other defects, selection of cold welding and other small heat-affected patch repair equipment in order to avoid the process of deformation.
Heat Treatment Process Operation There are many ways, including as plugging holes, tie holes, mechanically fixed, affordable heating method accurately select the direction of cooling of the mold and the direction of movement of the cooling medium, etc., reasonable heat treatment process is also reducing sophisticated mold deformation and effective measures.
