Q235 ordinary carbon structural steel is also known as A3 plate.

Ordinary carbon structural steel - common plate is a kind of steel material.

Q represents the yield limit of this material, and the latter 235 refers to the yield value of this material, which is around 235MPa.

And the yield value will decrease as the thickness of the material increases (plate thickness/diameter≤16mm, yield strength is 235MPa; 16mm<plate thickness/diameter≤40mm, yield strength is 225MPa; 40mm<plate thickness/diameter≤ 60mm, yield strength is 215MPa; 60mm<plate thickness/diameter≤100mm, yield strength is 205MPa; 100mm<plate thickness/diameter≤150mm, yield strength is 195MPa; 150mm<plate thickness/diameter≤200mm, yield strength is 185MPa).

Due to the low carbon content, the comprehensive performance is better, and the strength, plasticity and welding properties are well matched, and the use is the most extensive.

It consists of Q+number+quality grade symbol+deoxygenation method symbol. Its steel number is prefixed with "Q", which represents the yield point of the steel, and the following number represents the yield point value in MPa. For example, Q235 represents a carbon structural steel with a yield stress (σs) of 235 MPa.

If necessary, symbols indicating quality grade and deoxidation method can be marked after the steel number.

The quality grade symbols are A, B, C, D, respectively.

Symbol of deoxidation method: F means boiling steel;

b represents semi-killed steel:

Z represents killed steel;

TZ stands for special killed steel,

Killed steel may not be marked, that is, Z and TZ may not be marked. For example Q235-AF means A-grade boiling steel.

Carbon steel for special purposes, such as bridge steel, marine steel, etc., basically adopts the representation method of carbon structural steel, but the letter indicating the purpose is added at the end of the steel number.