ASTM A500 is an important technical standard developed by the American Society for Testing and Materials (ASTM), which is specifically used to regulate the production and quality control of cold-formed welded and seamless carbon steel structural pipes. The ASTM A500 standard covers carbon steel structural pipes in multiple shapes, including square, round, rectangular and special sections. This standard is widely used in projects such as bridges and buildings. Among them, Grade C is a specific material grade used in medium-strength structural scenarios. Compared with other grades, Grade C has achieved a good balance between strength and toughness.
Chemical composition and mechanical properties
Chemical composition
In order to ensure that ASTM A500 Grade C can meet the requirements in terms of mechanical properties, durability, etc., its chemical composition is strictly limited in the standard.
Core elements
Carbon (C) ≤ 0.35%: a key element that determines the strength and hardness of steel
Manganese (Mn) ≤ 1.40%: enhance hardenability and increase yield strength
Phosphorus (P) ≤ 0.035%: control impurity content to reduce cold brittleness risk
Sulfur (S) ≤ 0.035%: reduce hot brittleness and improve processing performance
Controllable elements (customized)
Copper (Cu): 0.20%~0.60%, Chromium (Cr), Nickel (Ni): trace addition (usually ≤ 0.30%)
Chemical composition
Mechanical properties
The mechanical properties of ASTM A500 Grade C are an important reflection of its application value, and its various performance indicators must be verified through rigorous testing
Tensile strength ≥ 400 MPa (58 ksi)
Yield strength ≥ 317 MPa (46 ksi)
Elongation ≥ 18% (at a gauge length of 50 mm)
Manufacturing process
Cold Forming Welding
The steel plate is rolled and welded into a tube through ERW or SAW. Strict NDT technology is used to ensure that the weld quality meets the standard requirements.
Seamless Process
The steel billet is processed into a tube through hot rolling or cold drawing technology. This process can produce high-precision and high-strength tubes.
Deoxidation Process
The deoxidation process is an important step in improving the purity of Grade C materials. Deoxidation treatment is carried out using barium-containing alloys (such as SiA1BaCa) to reduce the oxygen content in the steel, thereby improving the mechanical properties.
