316 316L Seamless Steel Tube Thickness 4.5-45mm OD 54-480mm

OD54～480mm thickness 4.5～45mm 316 316L Stainless Steel Seamless Round Pipe/Tube

Specifications and appearance quality

A. According to gb14975-2002 "Stainless Steel Seamless Steel Pipe", the steel pipe is usually 1.5 ~ 10m in length (variable feet), and the hot extruded steel pipe is equal to or greater than 1m. Cold-drawn (rolled) steel tube wall thickness of 0.5 ~ 1.0mm, 1.0 ~ 7m; Wall thickness greater than 1.0mm, 1.5 ~ 8m.

B, hot rolled (hot extrusion) steel pipe diameter 54 ~ 480mm altogether 45 kinds; There are 36 kinds of wall thickness 4.5 ~ 45mm. 65 kinds of cold-drawn (rolled) steel tubes with diameters of 6 ~ 200mm; There are 39 kinds of wall thickness between 0.5 and 21mm.

C. There shall be no cracks, folds, cracks, crackles, lamination and scarring defects on the inner and outer surfaces of steel pipes. These defects shall be completely removed (except for pipes used for mechanical processing), and the wall thickness and outer diameter shall not exceed negative deviations after removal. Other minor surface defects that do not exceed allowable negative deviations may not be removed.

D. The allowable depth of the straight. Hot-rolled and hot-extruded steel tubes, with diameters less than or equal to 140mm, no more than 5% of the nominal wall thickness, and the maximum depth no more than 0.5mm; Cold-drawn (rolled) steel tubes shall not be greater than 4% of nominal wall thickness, and the maximum depth shall not be greater than 0.3mm.

E. Both ends of the steel pipe should be cut at right angles and burrs removed.

Stainless steel seamless tube manufacturing process

1. Hot rolling (extruded seamless steel tube) : round tube billet → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → tube stripping → sizing (or reducing) → cooling → straightening → water pressure test (or defect detection) → marking → storage

The raw material of seamless tube rolling is round tube billet, round tube embryo is cut by cutting machine and processed billet with growth degree of about 1 meter, and sent to furnace for heating by conveyor belt. The billet is fed into a furnace to be heated at about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature control in furnace is the key problem. After the round tube billet comes out of the oven, it must go through the pressure punch. The most common puncher is the cone roll puncher, which has high production efficiency, good product quality, large diameter expansion and can wear a variety of steel. After perforation, the round tube is successively rolled by three rolls, cross - rolled, or extruded. After extrusion, take off the pipe and size. The sizing machine rotates into the steel embryo through the conical drill bit at high speed to drill and form the steel tube. The inner diameter of steel pipe is determined by the outer diameter length of drill bit of sizing machine. After sizing, the steel pipe enters the cooling tower and is cooled by spraying water. After cooling, the steel pipe is straightened. After straightening, the steel tube is sent by conveyor belt to metal flaw detector (or water pressure test) for internal flaw detection. If there are cracks, bubbles and other problems inside the steel pipe, it will be detected. Steel pipe quality inspection through strict manual selection. After quality inspection, paint on the pipe number, specification, production batch number and so on. And by the crane into the warehouse.

2. Cold drawing (rolling) seamless steel tube: round tube billet → 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.

The rolling method of cold-drawn (rolled) seamless steel tube is more complicated than that of hot-rolled (extruded) seamless steel tube. The first three steps of their production process are basically the same. The difference starts from the fourth step, after the round tube blank is hit empty, it should be hit and annealed. After annealing, special acidic liquid is used for pickling. After pickling, oil is applied. This is followed by a number of cold-drawn (cold-rolled) rebillet tubes, specialized heat treatment. After heat treatment, it is straightened.

 

FAQ

 

Q: What kind of work does your company do?
A: Our company is a professional manufacturer and trader.

We mainly produces stainless steel plate/pipe/coil/round bars, as well as aluminum plate/pipe/coil/bar.

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A:
(1) Prime quality and reasonable price.
(2) Wide excellent experiences with after-sale service.
(3) Every process will be checked by responsible QC which insures every product's quality.
(4) Professional packing teams which keep every packing safely.
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(6) Samples can be provided as your requirements.

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