The quality of the hot work of the Table Mould has a great influence on the performance and service life of the mould. In the actual life work, our mould shop needs to improve the design and production of various table mouls, and the specific operation will have problems.
The quenching deformation and cracking of the table mould working parts, as well as the early breaks in the working process, are related to the hot working process of the tool.
(1) Forging process is an important part of the manufacturing process of table mould parts. For table mould of high alloy tool steels, technical requirements are often imposed on the metallurgical structure (eg, material carbide distribution). In addition, the forging temperature range should be strictly controlled, the correct heating specification should be established, the correct forging method should be used, and the post-forging slow cooling or timely annealing should be performed.
(2) Preheat treatment. According to the material and requirements of the table mould processing parts, pre-heat treatment processes such as annealing, normalizing, quenching and tempering should be used to improve the structure, eliminate the structural defects of the forging blank, and improve the processing technology. After proper pre-heat treatment, the high carbon alloy table mould steel can eliminate the net secondary cementite or chain carbide, spheroidize and refine the carbide, and promote the uniformity of carbide distribution. This helps to ensure the quality of quenching and tempering and to improve the life of the table mould.
(3) Quenching and tempering. This is the key link in the heat treatment of table mould. If overheating occurs during quenching, not only will the workpiece produce greater brittleness, but it will also cause deformation and cracking during the cooling process, which will seriously affect the service life of the table mould. Special care should be taken to prevent oxidation and decarburization during quenching. The heat treatment process specification should be strictly controlled. Vacuum vacuum heat treatment can be used if conditions permit. After quenching, it should be tempered in time, and different tempering processes should be adopted according to technical requirements.
(4) Stress relief annealing. The working parts of the table mould should be subjected to stress relief annealing after roughing to eliminate internal stress caused by roughing and avoid excessive deformation and cracking caused by quenching. For high-precision table mould, it is necessary to eliminate stress and temper after grinding or electric machining, which is beneficial to stabilize table mould precision and improve service life.
