1. What is the minimum yield strength of API 5L Grade B carbon steel pipe?
Answer: The minimum yield strength of API 5L Grade B carbon steel pipe is 245 MPa, and the minimum tensile strength is 415 MPa, which can meet the strength requirements of long-distance oil and gas transportation.
2. What is Q235B carbon steel pipe? What does "B" stand for?
Answer: Q235B is a Chinese national standard (GB/T 700) carbon structural steel pipe. "Q" stands for "Quanfu" (yield strength), 235 means the minimum yield strength is 235 MPa, and "B" means the impact test is carried out at 20°C, with good toughness.
3. Can Q235B carbon steel pipe be used for high-pressure fluid transportation?
Answer: Generally not. Q235B is a low-carbon structural steel with low yield strength and tensile strength. It is mainly used for low-pressure pipelines, structural supports, etc. High-pressure fluid transportation should use high-strength grades such as A106 Grade B or API 5L Grade X42.
4. What is the chemical composition of Q355B carbon steel pipe?
Answer: Q355B complies with GB/T 1591 standard. Its main chemical composition is C ≤ 0.24%, Mn = 1.00-1.60%, P ≤ 0.035%, S ≤ 0.035%, Si ≤ 0.55%, and it contains a small amount of V, Nb, Ti to improve strength. The minimum yield strength is 355 MPa.
5. What is the difference between Q235B and Q355B carbon steel pipes?
Answer: The core difference is strength. Q235B has a minimum yield strength of 235 MPa, suitable for low-load and low-pressure scenarios; Q355B has a minimum yield strength of 355 MPa, with higher strength and toughness, suitable for medium-load structural pipes and medium-pressure pipelines.
