What are the differences between q345 and q355 steel?

Both q345 and q355 are low-alloy steels, and there is basically no difference between the two in terms of chemical composition and performance. To say the difference, that is, the yield strength of q345 low-alloy steel and q355 low-alloy steel is different. In q345 low alloy steel, q represents the yield strength of this material, and the latter 345 represents the yield value of this material is around 345mpa. The q in q355 low alloy steel also represents the yield strength of this material, and the latter 355 indicates that the yield value of this material is around 355mpa.

From this we can see that the yield strength of q355 low alloy steel is higher than that of q345 low alloy steel. Generally, the higher the strength, the more expensive the price, so the price of q355 low alloy steel is a bit more expensive than q345 low alloy steel. However, both q355 low-alloy steel and q345 low-alloy steel will decrease their yield value as the thickness of the material increases.