Q345 is a low alloy steel material commonly used in motor vehicles, bridges, ships, and construction. Also known as GB/T 1591, the Q signifies the yield point, and the 345 references the strength of yield. As such, it is essential to note that the yield value decreases as the material thickness increases.
Q345 Equivalent Materials
Q345 can also be replaced with equivalent materials, including A572 Grade 50 USA ASTM, Q355 China GB/T, and SPFC 590 Vietnam/Japanese JIS.
Characteristics of Q345
The yield strength of Q345 is where the material begins to deform plastically. Before hitting deformation, it will return to its original shape when stress is removed. For Q345, the yield strength is 345 MPa.
Like many in its grade, it will endure elongation before pulling apart, which typically occurs at 20 percent of its initial length. Q345 has a tensile strength rating of 470 to 660 MPa, which means that it can handle heavy-duty stress and use before ever failing.
The welding property of Q345 may be questioned by end-users, even though the welding properties are primarily affected by the chemical content. However, the production technology has rapidly and significantly improved after many years of research, which means that it is an excellent steel standard for structural purposes.
Q345 steel is from the 16 Mn steel grade, typically manufactured in a hot rolled steel coil or sheet or a hot rolled steel plate. It is an excellent choice when you need high-pressure durability.
Uses of Q345
Q345 has excellent mechanical properties, good performance in low temperatures, and excellent weldability and plasticity. It is most commonly used in building structures, low-pressure vessels, cranes, mechanical parts, bridges, ships, petroleum storage tanks, lifting machinery, power stations, mining machinery, general metal parts, and in other structures that are exposed to temperatures of -40 ℃ or below or experience high-loads.
Q345 Physical Properties
|Density||7.80 g/cc||0.282 lb/in³|
Q345 Mechanical Properties
|Hardness, Rockwell B||74||74|
|Tensile Strength, Ultimate||450 MPa||–|
|Tensile Strength, Yield||345 MPa||–|
|Elongation at Break||18 %||18 %|
|21 %||21 %|
|Bulk Modulus||160 GPa||23200 ksi|
|Shear Modulus||80.0 GPa||11600 ksi|
Q345 Component Elements Properties
|Component Elements Properties||Metric||US/Imperial|
|Carbon, C||<= 0.23 %||<= 0.23 %|
|Iron, Fe||98 %||98 %|
|Manganese, Mn||1.35 %||1.35 %|
|Phosphorus, P||<= 0.040 %||<= 0.040 %|
|Silicon, Si||<= 0.40 %||<= 0.40 %|
|Sulfur, S||<= 0.050 %||<= 0.050 %|
|Silicon, Si||0.15 – 0.40 %||0.15 – 0.40 %|
|Sulfur, S||0.050 %||0.050 %|
*Redstone Manufacturing does not guarantee the accuracy of the information contained within the above table. Some metrics have been rounded, converted, or estimated. Consult a qualified engineer to confirm the accuracy of the information contained on this webpage.