1. Different effects:
Q235 is an ordinary carbon structural steel with a yield strength of 235 MPa; Q355 is an ordinary low alloy structural steel with a yield strength of 355 MPa. Both are steel for engineering structures, but the latter has stronger load-bearing capacity and better use effect.
2. Different meanings:
Q235 steel is an ordinary carbon structural steel, that is, the old model A3 steel. Its yield point is 235MPa, its tensile strength is 375-500MPa, and it has many general uses.
Q355 steel is a low-alloy high-strength structural steel. It is a general name for a type of steel including 16Mn, 12MnV, 14MnNb, 18Nb, and 16MnRe. Its yield point is 355MPa and its tensile strength is 470-630MPa. It is an ordinary quality low alloy. steel.
3. Expression method
The complete expression method is: Q235--Quality grade symbol. The deoxidation method symbol quality grade is divided into A, B, C, D, and E. In order, A grade has poor quality and D grade has the highest quality. The deoxidation method symbols are F, b, Z and TZ, which respectively represent boiling steel, semi-killed steel, killed steel and special killed steel. However, in the grade representation method, the symbols Z and TZ can be omitted. The different grades of Q235A, Q235B, Q235C and Q235D mainly represent different impact temperatures.
