How to prevent longitudinal seam welded pipe thermal deformation
Date:2018-02-02 View:381 Tag:How to prevent longitudinal seam welded pipe thermal deformation
Deformed mold complex is often complicated, but as long as we grasp the deformation laws, analyze the causes, the use of different prevention methods is to reduce the deformation of the mold, and can control it. In general, precision mold hot deformation can be taken in the following ways to prevent.
(1) a reasonable choice. Precision mold should choose a good micro-deformation of steel (such as air-hardened steel), for severe segregation of carbide die steel should be reasonable quenching and forging heat treatment, the larger can not be dissolved in the die forging die steel can be second thin heat treatment .
(2) Mold structure design should be reasonable, the thickness should not be too bad, the shape should be symmetrical, to master the large deformation of the mold law, to reserve large-size mold, you can use a complex combination of structures.
(3) precision mold pre-heat treatment to eliminate the residual stress generated during processing.
(4) a reasonable choice of heating temperature control heating rate, for precision molds can take slow heating, preheating and other heat balance, reduce mold thermal deformation.
(5) under the premise of ensuring the hardness of the mold, the maximum use of pre-cooling, quenching or austempering grading process.
(6) precision molds in conditions permitting, as far as possible low-temperature vacuum heat treatment and quenching after quenching.
(7) For some precision molds, can be preheated, aging heat treatment, quenching and nitriding heat treatment to control the accuracy of the mold.
(8) Repair mold trachoma, porosity, wear and other defects, the choice of cold welding and other small thermal impact repair equipment to prevent process distortion.
In addition, the correct heat treatment process operations (such as plugging holes, holes, mechanical fixed, suitable heating method, the cooling direction and the cooling medium, the correct choice of mold and other direction of movement) and reasonable heat treatment process is to reduce the deformation of precision molds Effective measures.