Q345 is a steel material. It is a low-alloy steel (C<0.2%), widely used in construction, bridges, vehicles, ships, pressure vessels, etc. Q represents the yield strength of this material, and the following 345 refers to the yield value of this material, which is about 345 MPa. And the yield value will decrease as the thickness of the material increases.
Q345 has good comprehensive mechanical properties, acceptable low temperature performance, good plasticity and weldability, and is used as structures, mechanical parts, building structures, general Metal structural parts, hot-rolled or normalized, can be used in various structures in cold regions below -40°C.
Classification
Q345 can be divided into Q345A, Q345B, Q345C, Q345D, Q345E according to grade. What they represent is mainly the temperature of the shock.
Q345A level, no impact;
Q345B level, 20 degrees normal temperature impact;
Q345C level, 0 degree impact;
Q345D level, is -20 degree impact;
Q345E level, is -40 degree impact.
At different shock temperatures, the shock values are also different.
Chemical Composition
Q345A: C≤0.20, Mn≤1.7, Si≤0.55, P≤0.045, S≤0.045, V 0.02~0.15;
Q345B: C≤0.20, Mn≤1.7, Si≤0.55, P≤0.040, S≤0.040, V 0.02~0.15;
Q345C: C≤0.20, Mn≤1.7, Si≤0.55, P≤0.035, S≤0.035, V 0.02~0.15, Al≥0.015;
Q345D: C≤0.20, Mn≤1.7, Si≤0.55, P≤0.030, S≤0.030, V 0.02~0.15, Al≥0.015;
Q345E: C≤0.20, Mn≤1.7, Si≤0.55, P≤0.025, S≤0.025, V 0.02~0.15, Al≥0.015;
Q345 steel plate is widely used in petroleum, chemical industry, power station, boiler and other industries to make reactors, heat exchangers, separators, spherical tanks, oil and gas tanks, liquefied gas tanks, nuclear reactor pressure shells, boiler drums, liquefied petroleum gas Bottles, high-pressure water pipes of hydropower stations, turbine volutes and other equipment.
Q345 is a low-alloy steel plate, divided into five grades: A, B, C, D, and E. Q345A does not do low-temperature impact tests, and Q345B, Q345C, Q345D, and Q345E all do impact tests at temperatures of 20°C, 0°C, and -20°C, -40°C. Q345 executive standard: GB/T1591-2008 “Low Alloy High Strength Steel”.
Q355 is a low-alloy steel plate, divided into five grades: B, C, D, E, and F. Q355B, Q355C, Q355D, Q355E, and Q355F are all subjected to impact tests, and the temperatures are 0°C, -20°C, and -40°C respectively. , -60°C. Q355 executive standard: GB/T1591-2018 “Low Alloy High Strength Steel”.
Q345E steel plate is delivered in the state of controlled rolling, normalizing, normalizing + tempering, thermomechanical rolling (TMCP), etc., and Z-direction performance test is required according to customer needs, such as Q345E-Z15, Q345E-Z25, Q345E-Z35 etc. The flaw detection grades include national standard first detection, second detection and third detection, American standard A578 and A435, European standard SEL, Japanese standard JB/T 4730, etc.
Q355E steel plate is delivered in the state of controlled rolling, normalizing, normalizing + tempering, thermomechanical rolling (TMCP), etc. If necessary, Z-direction performance test is required according to customer needs, such as Q355E-Z15, Q355E-Z25, Q355E-Z35, etc. Q345E steel plate is delivered in the state of controlled rolling, normalizing, normalizing + tempering, thermomechanical rolling (TMCP), etc., if necessary, Z-direction performance test is required according to customer needs, such as Q345E-Z15 , Q345E-Z25, Q345E-Z35, etc.
Q345 :
Q355 :
