ASTM A573 Grade 70 is a carbon-manganese-silicon structural steel plate under the American ASTM standard, classified as a high-toughness carbon steel. It conforms to the ASTM A573/A573M standard and is specifically designed for boilers and pressure vessels. It is primarily used in the manufacturing of structural components requiring enhanced notch toughness at room temperature.

1. Construction: Used in bridges, high-rise buildings, and industrial facilities, where it can withstand heavy loads and stresses, ensuring structural safety and stability.

2. Machinery Manufacturing: Suitable for producing mechanical components like gears, shafts, and molds, meeting requirements for strength, toughness, and wear resistance.

3. Petrochemical Industry: Commonly used in reactors, heat exchangers, separators, spherical storage tanks, oil and gas tanks, and liquefied gas tanks, capable of withstanding high temperatures, pressures, and corrosive media.

4. Power Industry: Applied in boilers, pressure vessels, and steam turbine blades, ensuring the safe operation of power equipment.

Physical Properties

Density: Approximately 7.85 g/cm³, similar to that of standard carbon steel, providing a reliable reference for weight calculations and structural design.

Thermal Expansion Coefficient: Remains relatively stable across ambient to high-temperature ranges, aiding in dimensional control and deformation management for structures used in varying thermal environments.

Electrical and Thermal Conductivity: Exhibits good electrical and thermal conductivity, making it suitable for applications requiring electrical or heat transfer performance.

Production Process

Hot Rolling: Steel slabs are heated to high temperatures and rolled through multiple passes on a hot rolling mill to achieve the desired thickness and width. Hot rolling refines the steel's internal structure and enhances its mechanical properties.

Heat Treatment: Common methods include normalizing, quenching, and tempering, which further improve the steel's microstructure and properties, such as strength, toughness, and hardness.

Advantages and Disadvantages

Advantages: Offers excellent strength and toughness, enabling it to bear heavy loads while maintaining good deformation and fracture resistance; exhibits good weldability and is easy to process into various structural components; cost-effective and suitable for large-scale engineering projects.

Disadvantages: Relatively weak corrosion resistance, prone to rust and corrosion in humid or acidic/alkaline environments, necessitating anti-corrosion treatments; limited heat resistance, with performance stability inferior to heat-resistant steels at high temperatures, restricting its applicable temperature range.

Comparable Standards:

EN Equivalent: S355JR (similar properties, but not exact)