Carbon Steel

General Information

Carbon steels are steels whose alloying elements do not exceed the following limits: Element Max weight % C 1.00 Cu 0.60 Mn 1.65 P 0.40 Si 0.60 S 0.05

Designation

Carbon steels are designated by distinct AISI (American Iron and Steel Institute) four-digit numbers. The first two digits indicate the grades of the steels, while the last two digits give the nominal carbon content of the alloy in hundredths of a percent. Here is an example: XX :0.xx% average carbon content AISI 10 60 10 :Nonresulfurized grades 11 :Resulfurized grades 12 :Resulfurized and rephosphorized grades 15 :Nonsulfurized grades; max Mn content > 1% If a letter L or B shows up between the second and third digits of an AISI number, it means that this grade is either a Leaded steel or a Boron steel; Sometimes a suffix H is attached to a AISI number to indicate that the steel has been produced to prescribed hardenability limits. Examples are: Leaded steels :AISI 12L14, AISI 12L15... Boron steels :AISI 15B48H... H-steels :AISI 1038H, AISI 15B48H...

General Properties of Steels

The following table lists the typical properties of steels at room temperature (25°C). The wide ranges of ultimate tensile strength, yield strength, and hardness are largely due to different heat treatment conditions. Properties Carbon Steels Alloy Steels Stainless Steels Tool Steels Density (1000 kg/m3) 7.85 7.85 7.75-8.1 7.72-8.0 Elastic Modulus (GPa) 190-210 190-210 190-210 190-210 Poisson's Ratio 0.27-0.3 0.27-0.3 0.27-0.3 0.27-0.3 Thermal Expansion (10-6/K) 11-16.6 9.0-15 9.0-20.7 9.4-15.1 Melting Point (°C) 1371-1454 Thermal Conductivity (W/m-K) 24.3-65.2 26-48.6 11.2-36.7 19.9-48.3 Specific Heat (J/kg-K) 450-2081 452-1499 420-500 Electrical Resistivity (10-9W-m) 130-1250 210-1251 75.7-1020 Tensile Strength (MPa) 276-1882 758-1882 515-827 640-2000 Yield Strength (MPa) 186-758 366-1793 207-552 380-440 Percent Elongation (%) 10-32 4-31 12-40 5-25 Hardness (Brinell 3000kg) 86-388 149-627 137-595 210-620