Description
Q355 steel is a new Chinese steel grade of Low Alloy High Strength Structural Steel, which replaced Q345, the material density is 7.85 g/cm3. According to GB/T 1591 -2018, Q355 has 3 quality levels: Q355B, Q355C and Q355D. “Q” is the first letter of Chinese Pinyin: “qu fu dian”, which means Yield Strength, “355” is the minimum value of yield strength 355 MPa for steel thickness ≤16mm, and tensile strength is 470-630 Mpa.
| Steel Grade | Quality Grade | C % (≤) | Si % (≤) | Mn (≤) | P (≤) | S (≤) | Cr (≤) | Ni (≤) | Cu (≤) | N (≤) | Mo (≤) | B (≤) | Nb (≤) | V (≤) | Ti (≤) |
| Q355 | Q355B | 0.24 | 0.55 | 1.6 | 0.035 | 0.035 | 0.30 | 0.30 | 0.40 | 0.012 | – | – | – | – | – |
| Q355C | 0.20 | 0.030 | 0.030 | 0.012 | |||||||||||
| Q355D | 0.20 | 0.025 | 0.025 | – |
| Thickness or Dia. (d) mm; Yield Strength (≥N/mm2) | ||||||||||
| Steel Grade | Quality Level | d≤16 | 16< d ≤40 | 40 < d ≤63 | 63 < d ≤ 80 | 80 < d ≤ 100 | 100 < d ≤ 150 | 150 < d ≤ 200 | 200 < d ≤ 250 | 250 < d ≤ 400 |
| Q355 | Q355B | 355 | 345 | 335 | 325 | 315 | 295 | 285 | 275 | – |
| Q355C | – | |||||||||
| Q355D | 265 |
Charpy (V-notch) impact test temperature and impact absorption energy (KV2/J).
| Quality | Temperature | Longitudinal Impact Energy (J), ≥ | Transverse Impact Energy (J), ≥ |
| Q355B | 20 ℃ | 34 | 27 |
| Q355C | 0 ℃ | 34 | 27 |
| Q355D | -20 ℃ | 34 (for thickness ≥250mm) | 27 (for thickness ≥250mm) |
| China | ISO | EN | |||
| Standard | Grade | Standard | Grade | Standard | Grade |
| GB/T 1591 -2018 | Q355B | ISO 630-2 | S355B | EN 10025-2 :2004 | S355, S355JR |
| Q355C | S355C | S355J0 | |||
| Q355D | S355D | S355J2 |
A seamless pipe, as the name suggests, is a pipe without a seam or a weld-joint. Seamless pipes are thought to be able to withstand higher pressure, higher temperatures, higher mechanical stress and a corrosive atmosphere. It can be found in a wide range of applications such as in oil and gas, refinery, petrochemical, chemical, fertilizer, power, automotive, bearing, mechanical and structural.
The production of our seamless steel pipes is tightly regulated and all of the pipes we stock have been fully tested to international standards to ensure we only supply the highest quality products.
My company hot sale seamless steel line pipes:
ASTM A106 B seamless pipes, API 5L GR.B seamless steel pipes（1” to 24” sch40, sch80),