How to Prevent the Thermal Deformation of Longitudinal Seam Pipe
Date:2019-05-24 View(s):1774 Tag:How to Prevent the Thermal Deformation of Longitudinal Seam Pipe
Deformation precision die is often very complex, but as long as we grasp its deformation law, analyze its causes, adopt different prevention methods is to reduce the deformation of the die, and can control it. Generally speaking, the following methods can be used to prevent the thermal deformation of complex dies.
(1) Reasonable choice. Good micro-deformed steel (such as air quenched steel) should be selected for precision die. For die steel with serious carbide segregation, reasonable quenching and forging heat treatment should be adopted. For larger die steel, double refining heat treatment can not be carried out with forged die steel.
(2) The design of the die structure should be reasonable, the thickness should not be too bad, the shape should be symmetrical, the law of large deformation and deformation of the die should be mastered, the reserved margin should be large, and the precision die can be combined.
(3) Precision die pre-heat treatment to eliminate residual stress in the process of processing.
(4) Reasonable selection of heating temperature and control of heating speed can reduce the thermal deformation of precision die by adopting the method of slow heating and preheating.
(5) On the premise of guaranteeing the hardness of the die, the pre-cooling, step cooling and quenching or isothermal quenching process should be utilized to the maximum extent.
(6) Precision dies with allowable conditions shall be treated by low temperature vacuum heat treatment and quenching after quenching as far as possible.
(7) For some precision dies, pre-heat treatment, ageing heat treatment, quenching and nitriding heat treatment can be carried out to control the accuracy of the dies.
(8) When repairing defects such as trachoma, blowhole and wear, repair equipment with small heat effect such as cold welding can be selected to prevent process deformation.
In addition, proper heat treatment process operation (such as blocking hole, connecting hole, mechanical fixing, appropriate heating method, correct selection of cooling direction and movement direction of die in cooling medium) and reasonable heat treatment process are also effective measures to reduce the deformation of precision die.