，表示构筑物用无缝钢管牌号和化学成份
The construction of buildings using seamless steel pipes requires that they must meet certain standards and specifications. For example, according to the structural steel engineering code GB/T 8162-1999, seamless steel pipe is commonly categorized into several grades based on its chemical composition. For most building structures, low-carbon grades of seamless steel pipes are used.
Grade 10#, 20#, Q235, and Q345 are all low-carbon grades of seamless steel pipes with a carbon content of 0.17 - 0.20%, 0.17 - 0.20%, 0.12 - 0.20%, and 0.12 - 0.20% respectively. Grade 10# and 20# are mostly used for structures such as mechanical parts, pipes, and automobiles. Grade Q235 is the most common material for buildings. It is widely used for general structures such as bridges, ships, petroleum drilling, pressure vessels, and boilers. Grade Q345 is also suitable for building structures, but its yield strength is slightly better than that of Q235.
Grade 16Mn, 27SiMn, and 45# are medium-carbon grades of seamless steel pipes with a carbon content of 0.25 - 0.33%, 0.35 - 0.45%, and 0.42 - 0.50% respectively. 16Mn and 27SiMn are usually used for special purposes such as bridges, large-scale buildings, and ocean vessels. 45# is generally used for chemical equipment and hydraulic cylinder material.
Grade 35#, 45Mn2, 30CrMnSiA, 40Cr, 15CrMo, 20Mn2, 40Mn2, and 42MnSiA are high-carbon grades of seamless steel pipes with a carbon content ranging from 0.52 - 0.60%, 0.45 - 0.60%, 0.27 - 0.34%, 0.38 - 0.45%, 0.10 - 0.20%, 0.32 - 0.40%, 0.44 - 0.52%, and 0.43 - 0.50% respectively. These grades are relatively rare compared to lower carbon grades. They are often used for high strength components such as pressure vessels and screws.
All of the above grades of seamless steel pipes are commonly used in construction and are designed to meet the requirements of GB/T 8162-1999. They are used in a variety of applications due to their durability, corrosion resistance, and high strength-to-weight ratio. In addition to these grades, there are also various other grades of seamless steel pipes for special applications such as submarine pipelines.
