Recenly we have exported one batch of small diameter pipes with the size 1-1/4”, and it is produced by cold drawning, do you know what is the manufacturing process of cold drawing? Let’s learn about it.
The production process of cold drawn seamless steel pipe is: round tube blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → Water pressure test (flaw detection) → marking → storage.
Cold drawn seamless steel pipe is a kind of cold drawn seamless steel pipe material which is processed by cold drawing or hot rolling. The cold drawn seamless steel pipe has no oxide layer, bears high pressure and has no leakage, high precision, high finish, no deformation during cold bending, flaring, and flattening without cracks, etc., so it is mainly used to produce products for pneumatic or hydraulic components Such as cylinders or cylinders, can be seamless tubes.
1. Annealing is to heat the cold drawn seamless steel pipe to an appropriate temperature, use different heat preservation time according to the material and workpiece size, and then slowly cool down, the purpose is to make the internal structure of the metal reach or near the equilibrium state, to obtain good process performance and use Performance, or preparation for further quenching.
2. Normalizing is to heat the cold drawn seamless steel pipe to a suitable temperature and then cool it in the air. The effect of normalizing is similar to annealing, except that the resulting structure is finer. It is often used to improve the cutting performance of the material and sometimes used Some less demanding parts are used as the final heat treatment.
3. Quenching is to heat the cold-drawn seamless steel pipe after heat preservation and rapid cooling in quenching medium such as water, oil or other inorganic salts, organic aqueous solution. After quenching, the precision cold drawn seamless steel pipe becomes hard, but at the same time becomes brittle.
4. In order to reduce the brittleness of the cold drawn seamless steel pipe, the quenched cold drawn seamless steel pipe is kept at a suitable temperature higher than room temperature and lower than 650 ℃ for a long time, and then cooled. This process is called Tempered.