Differences between Q345 and Q235 materials
Thread Content
I would like to ask everyone: when designing products, we often face the issue of material selection. When should we choose Q235 and when should we choose Q345? Apart from the difference in yield strength, are there any fundamental differences between the two?
The cost of Q345 is higher than that of Q235
Strength, weldability, machinability!
Differences: The minimum yield strength of Q235 is 235 MPa, while that of Q345 is 345 MPa (the “Q” stands for the Chinese character meaning “yield”, and the subsequent number represents the minimum yield strength). 2. Their alloy content differs: Q235 is ordinary carbon steel, whereas Q345 is low-alloy steel. Q235 belongs to the category of carbon structural steel; it corresponds to grades A3 and C3 under the old standard GB700-79. Q345 is a low-alloy structural steel, corresponding to grades such as 12MnV, 16Mn, 16MnRE, 18Nb, and 14MnNb under the old standard 1591-88. As for their properties and applications, there are many variations. Q235 is used for metal structural components, as well as for parts that require low strength in their core areas, such as those subjected to carburizing or cyanidation processes; it is also used for tie rods, connecting rods, hooks, couplings, bolts, nuts, sleeves, shafts, and welded components； Q345--It exhibits good comprehensive mechanical properties as well as satisfactory performance at low temperatures; it has good plasticity and weldability. It is used for medium and low pressure vessels, oil tanks, vehicles, cranes, mining machinery, power plants, bridges, and other structures subject to dynamic loads, as well as for mechanical parts, building structures, and general metal components. It can be used in hot-rolled or normalized condition, and is suitable for various structures in cold regions with temperatures below -40°C ； The price will of course be a bit higher too!
Thank you to everyone above for their answers: handshake
This post was last edited by sunshy_yu on 2019-5-24 at 16:37. Under normal circumstances, it’s fine to use either of these two materials; just pay attention to their strength. However, if the medium is extremely and highly hazardous, Q235 cannot be used; Q345 can be used instead
On the equipment: Use Q345 at temperatures below 0°C
Thank you to everyone above for answering the question about the differences between Q345 and Q235 materials. 31 / Author: hemin882 / Post IDs: 2710486, 22430630
Q345 can be used as steel for pressure vessels, while Q235 cannot. Overall, Q345 is definitely of higher quality!
There are also containers made of Q235; they are all steels used for pressure vessels.