Location : home > News
Precision cold drawn seamless steel pipe having inner and outer wall oxide layer to withstand high pressure without leakage, high-precision, high-quality finish, cold deformation, flaring flattening without cracks, the surface has been treated for rust and other characteristics, mainly used for mechanical structure , hydraulic equipment and automotive motorcycle pneumatic or hydraulic components, such as cylinder or cylinders and so on. Cold drawn basic process is: Hot capillary -> capillary inspection, grinding -> Capillary pickling -> capillary pickled retest -> drawing -> fine pass before straightening pull -> pickling, lubrication -> finely drawn -> finished processing before -> storage.
Production Control Note:
1, capillary capillary wall thickness should be uniform, less internal and external surface defects; To configure the outer surface of the inner bore polishing and cleaning equipment defects.
2, re-examination compared with ordinary cold drawn steel, cold drawn precision seamless tube production increased capillary pickling hot-rolled re-examination process, primarily to ensure that the outer surface of the capillary without folding, cracks and other defects, ruled out the presence of the inner surface of the fold serious scribe, Ma surface defects such as capillary.
3, tools are generally cold drawn precision seamless steel pipe production tools used in surface finish requirements Ra0.4 above, the size accuracy H3 above, hardness in HRC70 or more. Also requires the drawing process can not appear in the plug or mold steel sticking phenomenon.
4, annealing annealing is a very important step in the production of all cold drawn tubes, annealing affect the performance of both their quality steel pipe also affects the oxide scale removal. Cold drawn precision steel bright annealing furnace oxidation no need to configure the device.
5, precision seamless steel pickling in sulfuric acid pickling process is easy to form Fe2O3, Fe3O4-based "black residue", forming a surface spots in the subsequent production. Fe2O3, Fe3O4 soluble in hydrochloric acid, to prevent the formation of dark spots in the pool of acid added 5-10g / l of NaCl.
6, lubrication should be used as a lubricant resin, the lubrication and phosphate lubricated (saponification) there were significant differences, pull out the pipe system showing the true nature of the iron matrix, both have high cold rolling tube-like finish beautiful appearance and color.
Production of cold drawn precision seamless steel tubes for industrial control including mold design, annealing, pickling and lubrication controlled conditions, and should do a good job in capillary quality testing, refurbishing.