Chemical Composition(%)
| Standard | Grade | Chemical Components (%) | |||||||
|
|
| C | Si | Mn | P | S | Mo | Cr | V |
| ASTM A519 | 4130 | 0.28-0.33 | 0.15-0.35 | 0.40-0.60 | ≤0.040 | ≤0.040 | 0.15-0.25 | 0.8-1.10 | / |
Mechanical Properties
| Grade | Delivery | Tensile Strength | Yield Strength | Elongation | Hardness |
|
| Condition | (Mpa) Min. | (Mpa) Min. | (%) Min. | (HB) Min. |
| 4130 | HR | 621 | 483 | 20 | 89 |
|
| SR | 724 | 586 | 10 | 95 |
|
| A | 517 | 379 | 30 | 81 |
|
| N | 621 | 414 | 20 | 89 |
Cold Drawn Seamless Steel Pipe Delivery Condition
| Designation | Symbol | Description |
| Cold drawn/hard | +C | No heat treatment after the final cold drawing process |
| Cold drawn/soft | +LC | After the final heat treatment there is a suitable drawing pass |
| Cold drawn and stress relieved | +SR | After the final cold drawing process there is a stress relief heat treatment in a controlled atmosphere |
| Annealed | +A | After the final cold drawing process the tubes are annealed in a controlled atmosphere |
| Normalized | +N | After the final cold drawing operation the tubes are normalized in a controlled atmosphere |
Application
Cold Drawn Carbon steel seamless pipes are extensively applied in the nuclear device, gas conveyance, petrochemical, shipbuilding and boiler industries, with characteristics of high corrosion resistance combined with suitable mechanical properties. - Nuclear device - Gas conveyanceAnnealing After the goods are cold drawn to sizes, the tubes are put on annealing furnace for heat treatment and normalising. Straightening Post annealing, the goods are passed through a seven roller straightening machine to achieve proper straightening of the tubes. Eddy current Post straightening, each tube is passed through eddy current machine to detect for surface cracks and other defects . Only the tubes that pass eddy current are fit for delivery to customers. Finishing Each tube is either oiled with corrosion resistant oil or varnished for surface protection and corrosion resistant as per customers requirement, each tube end is covered by plastic end caps to avoid damage in transit, the marking and specs are put and the goods are ready for dispatch.