GB Q235 ordinary structural carbon steel plate for pipe,flange and pipe fittings

What is Q235,The difference between Q235A and Q235B?

Ordinary carbon steel – General Board, is a steel material. Q represents the yield of this material, behind the 235, refers to the yield value of this material at about 235. And the thickness of the material will increase its yield value decreases. Q235A, Q235B, Q235C, Q235D.

This is a class distinction represents mainly the impact of temperature differs from mine! A, B, C, D, except that, referring to the different impact of their performance in the temperature. Namely:

Q235A level, is not to shock;

Q235B grade is 20 degrees room temperature impact;

Q235C level, is 0 degrees shocks;

Q235D level is -20 degrees shock.

The impact of different temperature, shock value are different. Element content: A, B, C, D sulfur content in descending order; the same phosphorus content of A and B, C, followed by phosphorus content, D phosphorus content of at least Q235 chemical composition of all levels: Q235 points A, B, C, D four (GB700-88)

• Q235A C 0.14~0.22% Mn0.30~0.65 Si≤0.30 S≤0.050 P≤0.045
• Q235B C 0.12~0.20% Mn0.30~0.670 Si≤0.30 S≤0.045 P≤0.045
• Q235C C≤0.18% Mn0.35~0.80 Si≤0.30 S≤0.040 P≤0.040
• Q235D C≤0.17% Mn0.35~0.80 Si≤0.35 S≤0.040 P≤0.035

Its deoxidation method, may be employed F, b, z are represented by boiling steel, flat killed steel, killed steel. Boiling steel is inferior steel deoxidation incomplete, ductility and toughness. Welded structure of this material, when the joint is prone to crack under dynamic loads. Should not work at low temperatures, sometimes produce hardening. In contrast, high quality and uniform killed steel, ductility and toughness are good.

Q235 Mechanical behavior Tensile strength （σb/MPa）：

375-500 Elongation（δ5/%）： ≧26（a≦16mm） ≧25（a>16-40mm） ≧24（a>40-60mm）， ≧23（a>60-100mm） ≧22（a>100-150mm）， ≧21（a>150mm） Where in a is the thickness or diameter of steel.