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 steel belongs to 16Mn steel grade, usually it is produced in hot rolled state, hot rolled steel plate, hot rolled steel coil/sheet, it has comprehensive mechanical and welding property, as it shows good performance in structural purposes, it is widely used as welding structural part in manufacturing of ship, railway and vehicles, bridges, boiler, pressure vessel container, steel oil tank, etc. Yield point of Q345 steel plate decreases as plate 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.
Physical Properties of Q345
| Physical Properties | Metric | US/Imperial |
|---|---|---|
| Density | 7.80 g/cc | 0.282 lb/in³ |
Mechanical Properties of Q345
| Steel Grade | Yield Strength Mpa | Tensile Stregth Map | Elongation % |
|---|---|---|---|
| Q345 GradeA | 345 | 470-630 | 21 |
| Q345 GradeB | 345 | 470-630 | 21 |
| Q345 GradeC | 345 | 470~630 | 22 |
| Q345 GradeD | 345 | 470~630 | 22 |
| Q345 GradeE | 345 | 470~630 | 22 |
Chemical Composition of Q345
| Steel Grade | C≤ | Mn | Si≤ | P≤ | S≤ | V | Nb | Ti | Al≥ |
|---|---|---|---|---|---|---|---|---|---|
| Q345 GradeA | 0.2 | 1.00~1.60 | 0.55 | 0.045 | 0.045 | 0.02-0.15 | 0.015-0.060 | 0.2 | - |
| Q345 GradeB | 0.2 | 1.00~1.60 | 0.55 | 0.04 | 0.04 | 0.02-0.15 | 0.015-0.060 | 0.2 | - |
| Q345 GradeC | 0.2 | 1.00~1.60 | 0.55 | 0.035 | 0.035 | 0.02-0.15 | 0.015-0.060 | 0.2 | 0.015 |
| Q345 GradeD | 0.2 | 1.00~1.60 | 0.55 | 0.03 | 0.03 | 0.02-0.15 | 0.015-0.060 | 0.2 | 0.015 |
| Q345 GradeE | 0.2 | 1.00~1.60 | 0.55 | 0.025 | 0.025 | 0.02-0.15 | 0.015-0.060 | 0.2 | 0.015 |
Q345 steel equivalent standard
ASTM/EN/JIS| Standard | Grade | Application |
|---|---|---|
| GB 713-2008 ASTM A537-08 JIS G3115 | Q245R (20g/20R); Q345R (16Mng/16MnR) Class 1/2/3 SPV235; SPV315; SPV355 | Steel for boiler and other pressure vessels |
| GB/T 1591-2008 EN 10028-3-2003 EN 10025-2004 ASTM A572-07 ASTM A588-05 | Q345 (A/B/C/D/E); Q390; Q420 P355N S420N Grade 50; Grade 60 Grade A; Grade B | High strength low alloy structural steel |