Cold drawn precision seamless steel tube with internal and external wall without oxidation layer, withstand high pressure leak-free, high-precision, high finish, cold bending deformation, no crack expansion, the surface has been used for anti-rust treatment characteristics, mainly for mechanical structure, hydraulic equipment and motor vehicles, pneumatic or hydraulic components, such as cylinders or oil cylinders.
Cold drawing of the basic process is: hot-rolled capillary-> Capillary inspection, grinding-> Capillary pickling-> Capillary pickling after the retest-> Cold drawn-> Fine pull road before straightening-> pickling, lubrication-> Fine Pull-> finished products before processing-> warehousing.
Production needs attention control:
The thickness of the capillary wall should be uniform, the internal and external surface defects are less, external surface polishing and internal hole defect cleaning equipment should be configured.
Compared with ordinary cold drawn steel pipe, cold drawn precision seamless pipe production increased hot-rolled capillary pickling process, the main is to ensure that the outer surface of the capillary without folding, crack and other defects, excluding the internal surface of the collapse, serious crossed, pock and other defects of the wool tube.
3. Tools General cold drawn precision seamless steel tube production of the tool used in the surface finish requirements in Ra0.4 above, dimensional accuracy of H3 above, hardness requirements in HRC70 above.
At the same time, drawing process can not appear in the head or Die sticky steel phenomenon.
4, annealing Annealing is a very important process in all cold drawing pipe production, the quality of annealing affects both the performance of steel pipe and the removal of oxidized iron.
Cold Drawn precision steel pipe needs to be equipped with no oxidation bright annealing furnace equipment.
5, pickling Precision seamless steel tube in sulfuric acid pickling process easily formed to Fe2O3, Fe3O4 mainly "black slag", in the subsequent production of surface black spots.
Fe2O3, Fe3O4 soluble in hydrochloric acid, in order to prevent the formation of dark spots in the acid pool to add 5-10g/l NaCl.
Resin should be used as a lubricant, this lubrication with phosphating plus lubrication (saponification) compared to the obvious difference, drawn out of the steel pipe to show the nature of the iron-based, both high smoothness and cold rolled tube-like beautiful appearance and luster. Production of cold drawn precision seamless steel tube industrial control, including mold design, annealing, pickling, lubrication and other conditions control, at the same time should be in the quality of capillary inspection, renovation work well.