Cold drawing and hot rolled seamless steel pipe

Seamless steel pipe cold drawing (rolling) : round billet - heat - punch to heading, annealing and pickling to apply oil (copper), multi-channel time cold drawing (cold) and billet tube - heat treatment - straightening to hydrostatic test (NDT) - > tag, put in storage.

Hot rolled (extrusion seamless steel tube) : the circular tube billet - heat - punch - three-roll skew rolling, rolling, or pressing - to take off the tube and sizing (or reducing) - cooling - the tube billet - straightening - hydrostatic test (or inspection) to tags, put in storage.

Two kinds of structural steel pipe process steps

Cold drawn steel tube with hot rolled steel coils as raw material, after acid pickling to remove oxide skin for cold rolling, the finished product is hard, because of cold work hardening caused by deformation of continuous cold rolling hard roll strength, increase hardness, toughness and plastic index decreased, so the stamping performance will deteriorate, can only be used for simple deformation of the parts. Hard coil can be used as a raw material, hot dip galvanized factory for hot dip galvanizing unit Settings are annealed wire. Hard coil weight generally in June to 13.5 tons, coil diameter is 610 mm.

General cold rolling plate, coil shall be continuous annealing unit (CAPL) or bell type annealing furnace eliminate cold work hardening and rolling stress, corresponding mechanics performance index prescribed by the standard.

Cold rolled steel plate surface quality, appearance, dimension precision are better than that of the hot rolled plate, and its products right rolling thin thickness to 0.18 mm or so, so favored by the users. For the substrate to cold rolled steel coils products deep processing, become the high value-added products. Such as electric galvanized, hot dip galvanized, electric galvanized fingerprint resistant steel plate and vibration compound steel plate, belt, PVC compound steel plate, etc., make the product is beautiful and fine qualities such as high corrosion, has been widely applied. Must be annealed cold rolled steel coils for finishing, including cutting head, tail, trimming, leveling, leveling, heavy volume, or longitudinal shear plate, etc. Cold-rolled products are widely used in automotive, home appliances, instrument switch, building, office furniture and other industries. Steel strapping after each bag is 3 ~ 5 tons in weight. Flat volume classification is commonly 3 ~ 10 tons/volume. Coil diameter 610 mm.

Hot-rolled carbon steel pipe of continuous casting slab or slab as raw material, by step heating furnace, high pressure water descaling after entering the roughing mill, roughing expected by the cutting head, tail, and then into the finishing mill, and the implementation of computer control rolling and finishing after through laminar cooling and the winder, become straight hair volume. Straight hair volume of head and tail often show tongue shape and fish shape, thickness and width accuracy is poorer, side often exists defects such as wave shape, folding, tower. The volume weight is heavier, coil diameter is 760 mm. (general pipe industry like to use. To pass through the cutting head and cutting tail straight hair volume, trimming and straightening, level off of multichannel time after finishing line processing, cutting board or heavy volume, again become namely: hot rolled steel plate, flat hot-rolled coil, slitting and belt and other products. Hot rolling finishing if volume after acid pickling to remove scale and greased the hot-rolled pickling plate volumes. This product has a tendency to be local alternative manufacture, price moderate, loved by the masses of users.

If you would like to know more about this,pls visit:Hunan great steel pipe co.,ltd