Precautions of cold drawn precision steel pipe

The inner and outer wall of the cold drawn precision steel pipe has no oxidation layer. It bears high pressure and no leakage, high precision, high finish, cold bending, no deformation, smooth flared mouth without cracks, and rust prevention treatment on the surface. It is mainly used for mechanical structure, hydraulic equipment and pneumatic or hydraulic components for automobile and motorcycle, such as cylinders or cylinders.


The basic process of cold drawing is: hot rolling capillary, capillary inspection, grinding, capillary acid pickling, pickling, pickling, cold drawing, pre grinding, pickling, lubrication and treatment;


Production needs to be controlled.
1, capillary
The thickness of the capillary wall should be uniform and the internal and external surface defects are few.


2, recheck
Compared with ordinary cold drawn steel tubes, the production of cold drawn precision steel tubes has increased the reinspection process of hot rolled capillary acid washing. It is mainly to ensure that the outer surface of the capillary is not folded, cracks and other defects, the folds of the inner surface, and other defects of the dumplings and capillaries are excluded.


3, tools
The surface finish of ordinary cold drawn precision steel pipe production tools is Ra0.4 or more, and the dimension accuracy is above H3. The hardness requirement is more than HRC70. At the same time, the phenomenon of sticking to the head or die can not be observed in drawing process.


4, annealing
Annealing is a very important step in the production of all cold drawn tubes. The quality of annealing affects the performance and descaling of the steel tubes. The cold drawn precision steel tube should be equipped with no oxidizing bright annealing furnace equipment.


5, pickling
In the pickling process, the "black slag", which is mainly composed of Fe2O3 and Fe3O4, is easily formed in the precision steel pipe, and the surface black spots are formed in subsequent production. Fe2O3, Fe3O4 dissolved in hydrochloric acid to prevent the formation of dark spots in the acid pool and add 5-10g / L NaCl.


6, lubrication
The lubricant should be used as a lubricant, which is distinctly different from the phosphating and lubricating (saponification). The iron pipe pulled out shows the true nature of the iron matrix, both with high gloss and cold-rolled to a beautiful appearance.