Q345 is a steel material. It is a low-alloy steel (C <0.2%), widely used in bridges, vehicles, ships, buildings, pressure vessels. Q represents the yield of this material, behind the 345, the yield refers to the value of this material, approximately 345. And will increase the thickness of the material and its yield value decreases.
Q345A, Q345B, Q345C, Q345D, Q345E. This is a class distinction represents mainly the impact of temperature differs only!
Q345A level, it is not to shock;
Q345B grade is 20 degrees room temperature impact;
Q345C level, is 0 degree impact;
Q345D level is -20 degree impact;
Q345E level is -40 degrees impact.
The impact of different temperature, shock value are different. In the plate, the case of low-alloy series. In low-alloy material where such material is the most common.
Q235 and Q345 of difference
Difference of Yield strength limit:
A: Yield strength limit Q235 is 235MPa,
B: yield strength limit Q345 is 345MPa (Q of Chinese characters meaning "bend", which value represents the yield strength of the lower back)
2, the two different alloy content:
A: Q235 ordinary carbon steel, Q235 is carbon steel, Q235-- metal structure, the center of strength less demanding carburizing or cyanide parts, rod, rods, hooks, coupler, bolts and nuts, set cylinder, shaft and weldments
B: Q345 low-alloy steel, Q345 low-alloy structural steel, Q345-- good mechanical properties, low temperature performance can, good ductility and weldability, used as the low-pressure vessels, tanks, vehicles, cranes, mining machinery, structural, mechanical parts, building structures, metal structures in general, hot-rolled or normalizing state power plants, bridges, etc. to withstand dynamic load of use, can be used for all kinds of steel above -40 ℃ cold areas.