ASTM A105 is a widely used standard specification for carbon steel forgings, especially for piping components such as flanges, fittings, and valves. Many buyers often ask about the chemical composition requirements of ASTM A105, particularly the minimum silicon content.

According to the standard, the silicon (Si) content of ASTM A105 shall not be lower than 0.15 %wt, and it should not exceed 0.35 %wt. The presence of silicon helps improve the steel’s strength, toughness, and resistance to oxidation at elevated temperatures.

Here is the typical chemical composition range of ASTM A105:

• Carbon (C): ≤ 0.35 %

• Manganese (Mn): 0.60 – 1.05 %

• Silicon (Si): 0.15 – 0.35 %

• Phosphorus (P): ≤ 0.035 %

• Sulfur (S): ≤ 0.040 %

• Copper, Nickel, Chromium, Molybdenum, Vanadium: ≤ 0.40 % each (residual elements)

In addition to chemical composition, ASTM A105 forgings must also meet mechanical property requirements such as:

• Tensile Strength: ≥ 485 MPa

• Yield Strength: ≥ 250 MPa

• Elongation: ≥ 22 %

• Reduction of Area: ≥ 30 %

• Hardness: ≤ 187 HBW

These requirements ensure that ASTM A105 carbon steel forgings offer reliable performance in high-pressure and high-temperature piping applications.

The silicon content in ASTM A105 carbon steel shall not be lower than 0.15 %wt, which is critical for maintaining the steel’s mechanical properties and workability. When purchasing ASTM A105 forgings, buyers should always check the material test certificate (MTC) to confirm that the chemical and mechanical requirements meet ASTM standards.