Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E

2021-02-281832

Q345 Steel Properties

Q345 steel is a Chinese GB standard Low Alloy High Strength Structural Steel, material density is 7.85 g/cm3, tensile strength is 470-630 Mpa, and yield strength is 345 MPa, it has better properties than Q235. According to GB/T 1591 – 2008, Q345 material has 5 quality grades: Q345A, Q345B, Q345C, Q345D and Q345E.

Q345 steel has good weldability, cold & hot workability and corrosion resistance. Widely used in bridges, ships, boilers, pressure vessels, petroleum storage tanks, lifting transport machinery and other high-load welded structural parts.

Meaning & Designation

"Q" is the first letter of Chinese Pinyin: "qu fu dian", that means Yield Point, "345" is the minimum value of yield strength 345 MPa for steel thickness ≤16mm.

Datasheet and Specification

Datasheet and specification are listed in the tables below, including chemical composition, machenical properties, etc.

Chemical Composition of Q345 Steel

Based on melting analysis.

Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E Materials 1

Notes: The P and S contents of profiles and bars can be increased by 0.005%, and the upper limit of Grade A steel can be 0.0045%.

Material Q345 Mechanical Properties

Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E Materials 2

Notes:

d= Thickness or wire diameter in mm;

1 MPa = 1 N/mm2

Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E Materials 3

Charpy Impact

Charpy (V-notch) impact test temperature and impact absorption energy (KV2/J), thickness (t).

Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E Materials 4

Material Q345 Equivalent

Q345 steel: Q345A, Q345B, Q345C, Q345D, Q345E equivalent to US ASTM, European Germany DIN, British BS, France NF, Japan JIS, and ISO Standard (For Reference).

Notes: Q345 steel has been replaced by Q355 in the latest version of GB standard "GB/T 1591 – 2018", the previous version is "GB/T 1591 – 2008".

Q345 Carbon Mild Steel Q345A Q345B Q345C Q345D Q345E Materials 5