Difference between q345 and q235

1. the lower limit of yield strength is different:

Q235: The lower limit of yield strength of Q235 is 235MPa. Q345: The lower limit of yield strength of Q345 is 345MPa (the meaning of Q is the flexion of Chinese characters, and the following value represents the lower limit of yield strength);

2. Different types of steel:

Q235: Q235 is ordinary carbon steel. Q345: Q345 is low alloy steel;

3. Different composition:

Q235: Q235 is carbon structural steel, compared with the old standard GB700-79 grade A3, C3. Q345: low alloy structural steel, with the old standard 1591-88 grade 12MnV, 16Mn 16MnRE, 18Nb, 14MnNb. The lower limit of the yield strength of Q235 is 235 pressure, and the lower limit of the yield strength of Q345 is 345 pressure (the meaning of Q is the flexion of Chinese characters, and the following value represents the lower limit of the yield strength).

4. the alloy content of the two is different:

Q235 is ordinary carbon steel and Q345 is low alloy steel. Q235 is carbon structural steel, compared with the old standard GB700-79 grade A3, C3.

Q345 is a low alloy structural steel, compared with the old standard 1591-88 grade 12MnV, 16Mn 16MnRE, 18Nb, 14MnNb.

Q235 Metal structural parts, carburized or cyanide parts with low core strength requirements, tie rods, connecting rods, hooks, couplings, bolts and nuts, sleeves, shafts and welds.

Q345 has good comprehensive mechanical properties, low temperature performance is also available, good plasticity and weldability, used as medium and low pressure vessels, oil tanks, vehicles, cranes, mining machinery, power stations, Bridges and other dynamic load bearing structures, mechanical parts, building structures, general metal structural parts, hot rolled or normalizing state use, can be used for various structures in cold areas below minus 40 degrees Celsius.