China GB/T1591 Q345B low alloy steel Mechanical Properties

China GB/T1591 Q345B low alloy steel is a Chinese standardized low alloy, medium tensile strength steel made with a hot-rolling process, and is used for a number of manufacturing purposes. It is a steel with less than 0.2 percent of its composition made up of carbon, less than 0.55 percent of its composition made of silicon and several impurities (mostly sulfur, chromium and nickel).

China GB/T1591 Q345B low alloy steel Chemical Composition (%):

Grade	Chemical Composition(%)
	C	Mn≥	Si	P	S
GB/T1591 Q345B	0.20	1.70	0.50	0.035	0.035

China GB/T1591 Q345B low alloy steel Yield Strength:
The yield strength or yield point is the material property defined as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed, Yield strength of Q345B steel is 345 Mega Pascal. Like most steels of its grade, it suffers elongation before it pulls apart, typically at 20-21 percent of its initial length.

Grade	Mechanical Property
	Tensile Strength(MPa)	Yield Strength(MPa)	% Elongation in 2 in.(50mm) min	Impacting Test Temperature(°C)
GB/T1591 Q345B	470-630	345	20	20

China GB/T1591 Q345B low alloy steel Tensile strength:
The tensile strength of a material is the maximum amount of tensile stress that it can take before failure, for example breaking. Steel tensile strength is expressed in units of force divided by cross sectional area; in the Metric system, this unit is known as the Pascal. One Pascal is a Newton (the force needed to accelerate a one kilogram object to a velocity of one meter per second) per square meter. The tensile strength of Q345B steel is rated at 470 to 630 Mega Pascal (where mega is million).

China GB/T1591 Q345B low alloy steel Application:
GB/T1591 Q345B steel is widely used in bridges, vehicles, ships, buildings, pressure vessels and so on.