Q345

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

Q345 is low alloy structural steel with good mechanical properties, low temperature performance, plasticity and good weldability, it is mostly used in low pressure vessel, oil tank, vehicles, cranes, mining machinery, power stations, mechanical parts, building structure, general metal parts, Q345(E) steel plate is always delivered in hot rolled or normalizing state, can be used in areas where its temperature is above -40 ℃.

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

Welding property of Q345 steel is occasionally questioned by end users, although welding property is mainly affected by its chemical content, its production technology has been improved after all those years of research, and has been proved to be one excellent steel standard for steel structure purposes, you can contact us if there’s any doubt in your mind.

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