A105 Carbon Steel: Best Properties, Applications, and Standards

A105 carbon steel is a common and adaptable material that is valued for its superior mechanical qualities ability to withstand corrosion, and adaptability to a variety of settings. 

The temperature range for A105 material is -20°F to 400°F (-29°C to 204°C). It is not recommended to use A105 at temperatures above 400°F (204°C) because the carbide phase of the steel may convert to graphite, which can make the steel brittle.

A105 Carbon Steel Composition

A105 carbon steel is a kind of carbon steel that is forged and mostly composed of carbon and iron, with trace amounts of additional alloying elements. 

• Carbon: 0.42%

• Chromium: 1.00%

• Manganese: 0.80%

• Molybdenum: 0.25%

• Sulfur: 0.03%

• Phosphorus: 0.04%

The controlled composition ensures that A105 steel exhibits desirable properties such as good machinability, weldability, and a balance between strength and ductility.

Mechanical properties of A105 carbon steel

• Tensile Strength: Typically ranging from 485 MPa to 655 MPa.

• Yield Strength: Generally around 250 MPa to 450 MPa.

• Elongation: Typically around 30% to 35%.

• Hardness: After heat treatment, the hardness typically falls within the range of 187 to 229 Brinell.

Heat treatment requirements for A105 steel 

The steel must be quenched in oil or water from a temperature of 1000°F to 1050°F (538°C to 566°C).

The steel must be tempered at a temperature of 400°F to 900°F (204°C to 482°C).

Relevant Standards for A105

A105 carbon steel is governed by several standards to ensure consistent quality and compatibility with various applications. The key standards include:

ASTM A105 standard: This is the most common standard for A105 carbon steel. It covers forgings intended for use in pressure systems, such as flanges and fittings, for high-temperature and high-pressure services.

ASME B16.5 standard: This standard defines dimensions and tolerances for A105 steel flanges and flanged fittings used in pressure applications.

ASTM A350 standard: This standard includes specifications for carbon and low-alloy steel forgings, including those made from A105 steel for applications requiring impact toughness testing.

Applications of A105 Carbon Steel

A105 carbon steel finds applications in a wide range of industries due to its favorable combination of properties. Some notable applications include:

Piping and Flanges: A105 steel is extensively used in piping systems where it is forged into various types of flanges for connecting pipes, valves and other components. It can be used to manage fluids and gases in a variety of industries, including oil and gas, petrochemical, and chemical processes due to its weldability and resistance to corrosion.

Pressure Vessels: This material is employed in the fabrication of pressure vessels, which are used to store and transport liquids or gases under high pressure. Its strength and toughness properties make it suitable for safely containing pressurized substances.

Valve Components: A105 carbon steel is utilized for producing valve components like valve bodies, stems, and bonnets. Its robust properties ensure reliable performance in controlling fluid flow and handling varying pressures.

Fittings and Forgings: The material’s malleability allows it to be forged into complex shapes, making it suitable for various fittings, flanges, and forgings used in industrial equipment.

Structural Components: In some cases, A105 steel is used for structural applications that require moderate strength and machinability.

What is  difference between A105 and A105N material

The main difference between A105 and A105N material is that A105N requires that the steel be normalized after forging. Normalization is a heat treatment process that improves the steel’s uniformity and toughness.

Here is a table summarizing the differences between A105 and A105N material:

Property	A105	A105N
Chemical composition	Same	Same
Mechanical properties	Same	Same
Heat treatment	Quenched and tempered	Quenched and tempered, normalized after forging
Typical applications	Gears, shafts, axles, springs, pins, bearings, tools, drill bits, mining machinery, construction equipment, firearms	Same

A105N is typically used in applications where the highest level of toughness is required, such as in the construction of pressure vessels and piping systems. A105 can be used in these applications as well, but it may not provide the same level of toughness.

What group number is A105 material?

A105 is a material grade of carbon steel that belongs to group 1.1 in the ASME B16.5 standard. Group 1.1 materials are forged carbon steels that have a minimum tensile strength of 1000 MPa (14500 psi). They are typically used in applications where high strength and toughness are required, such as in the construction of pressure vessels and piping systems.

The other materials that belong to group 1.1 in the ASME B16.5 standard are:

• ASTM A106
• ASTM A350-LF2
• ASTM A350-LF3
• ASTM A514
• ASTM A694

The UNS number for ASTM A105 is K03504. UNS stands for Unified Numbering System, which is a system for identifying and classifying materials. The K03504 UNS number specifically identifies ASTM A105 carbon steel forgings.

• The UNS number is made up of four parts:
• The first two digits, K0, identify the material group. In this case, K0 identifies carbon steels.
• The third digit, 3, identifies the specific alloy within the material group. In this case, 3 identifies ASTM A105 carbon steel.
• The fourth digit, 5, is a check digit that is used to ensure that the UNS number is entered correctly.

What is ASTM A105N material grade?

ASTM A105N is a material grade of carbon steel that is equivalent to ASTM A105. The only difference between the two grades is that ASTM A105N requires that the steel be normalized after forging. Normalization is a heat treatment process that improves the steel’s uniformity and toughness.

 Chemical composition of ASTM A105N 

• Carbon: 0.42% max
• Chromium: 1.00% max
• Manganese: 0.80% max
• Molybdenum: 0.25% max
• Sulfur: 0.035% max
• Phosphorus: 0.040% max

The mechanical properties of ASTM A105N steel in the quenched and tempered condition are as follows:

• Tensile strength: 1000 MPa
• Yield strength: 800 MPa
• Hardness: 29-34 HRC

Heat treatment requirements for ASTM A105N steel 

• The steel must be normalized at a temperature of 1600°F to 1650°F (871°C to 900°C).
• The steel must then be quenched in oil or water from a temperature of 1000°F to 1050°F (538°C to 566°C).
• The steel must then be tempered at a temperature of 400°F to 900°F (204°C to 482°C).

What are changes in astm a105 latest edition changes

The latest edition of ASTM A105 is the 2023 edition, which was published on May 1, 2023. The 2023 edition includes a number of changes from the previous edition, including:

• New requirements for the chemical composition of A105 steel.
• New requirements for the mechanical properties of A105 steel.
• New requirements for the heat treatment of A105 steel.
• New requirements for the nondestructive testing of A105 steel.

 Key changes in the 2023 edition of ASTM A105:

The carbon content of A105 steel is now limited to 0.40% maximum, down from 0.42% in the previous edition. This change was made to improve the machinability of A105 steel.

The tensile strength requirement for A105 steel in the quenched and tempered condition is now 1000 MPa minimum, up from 980 MPa in the previous edition. This change was made to improve the strength of A105 steel.

The hardness requirement for A105 steel in the quenched and tempered condition is now 29-34 HRC, up from 28-32 HRC in the previous edition. This change was made to improve the toughness of A105 steel.

The heat treatment requirements for A105 steel have been clarified. The steel must now be quenched in oil or water from a temperature of 1000°F to 1050°F (538°C to 566°C). The steel must then be tempered at a temperature of 400°F to 900°F (204°C to 482°C).

The nondestructive testing requirements for A105 steel have been updated. The steel must now be ultrasonically tested to ensure that it is free of any defects that could affect its strength or toughness.

Conclusion

A105 carbon steel is a reliable and versatile material that finds widespread use in critical industries. It is an excellent material for applications requiring a combination of strength, machinability, and corrosion resistance due to its well-balanced composition and mechanical properties. By adhering to relevant standards, manufacturers ensure the quality and performance of A105 carbon steel products across various engineering applications.