Because of the coating on the surface of color coated sheet, there are many differences between color coated sheet and ordinary cold oxygen sheet and galvanized sheet in forming process. In view of the influence of some mechanical properties (such as
yield strength, elongation) and some coating properties (such as pencil hardness, T-bending value, impact work) of color coated sheet on forming process, enough attention should be paid to this. 。 The following items should be paid attention to in
(1) When the shape of parts is complex and the degree of deformation is large, multi-pass forming should be adopted. If formed at one time, the adhesion of the coating may be destroyed due to excessive deformation.
(2) Appropriate clearance should be set according to die shape, deformation characteristics and process conditions. The thickness of coating should be taken into account when setting clearance.
(3) Most coatings can be used as solid lubricants and meet the lubrication requirements of most forming processes. Some coatings can improve the lubricity of coatings by adjusting the formulation. If the lubricity of the coating is insufficient, the lubricity can be improved by applying oil, wax and peelable protective film. However, it should be noted that wetting agent solvents are easy to absorb dirt, should be removed before installation, and peelable protective film should be removed as soon as possible after processing.
(4) Reasonable processing speed should be set according to the condition of equipment, process conditions, shape of parts and other factors. Excessive deformation speed can easily lead to coating peeling. When the temperature is low, the flexibility of the coating decreases, so low temperature processing should be avoided. If the ambient temperature is low, the material should be preheated to a certain temperature before processing.
(5) The incision section produced during processing is prone to corrosion, so necessary protective measures should be taken, such as coating protective coatings, inserting rubber seals, etc.
(6) The burrs on the cut surface should be minimized to prevent the burrs from scratching the surface.
(7) All surfaces in contact with the coating should be kept clean and tidy, and the chips and metal particles generated during processing should be cleaned in time to prevent foreign bodies from damaging the coating surface.
(8) When processing, the wear of roll surface or die surface of forming roll should be minimized, the contact surface should be kept clean, and the defects such as indentation and scratch on the coating surface should be prevented.
(9) As far as possible, the construction method of factory pre-assembly and then on-site installation should be adopted, and protective measures should be taken to prevent damage to the coating during installation.
(10) If the surface of the coating is damaged during processing, special repairing coatings should be used in time to prevent corrosion at the damaged areas.