What is difference between A36 & Q235B steels?

What is difference between A36 & Q235B steels?

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What is difference between A36 & Q235B steels?

ASTM A36/A36M covers carbon steel shapes, plates,and bars of structural quality for use in riveted, bolted, or welded construction of bridges and buildings, and for general structural purposes.So it is used widely. Usually A36 steels are suggested to be instead by Q235B because of great similarities. However there are some differences between A36 and Q235B.

1. different chemical components

A36 will required different Mn components because of different thicknessof plates or diameters of round bars, if the size is below 20mm, there is no Mn component requirement.While Q235B required the Mn component between 0.3-0.7%. Others are similars, details reference below:

Table I: chemical components between A36 & Q235B

Grade

C %

Si %

P %

S %

Mn %

A36

≤0.25

≤0.4

≤0.04

≤0.05

-

Q235B

0.12-0.2

≤0.3

≤0.05

≤0.045

0.3-0.7

2. different mechanical components

A36 has higher Min Yield strength and Tensile strength than Q235B. And mostly Shanghai All-Win Iron & Steel can offer Q235B material with higher yield and tensile strength which can meet the Min those value of A36.

Table II: mechanical properties between A36 & Q235B

Grade

Yield Strength

MPa

Tensile Strength

MPa

Elongation

A36

≥250

400-550

≥20

Q235B

≥235

370-500

≥21

Totally speaking, if there is clarified specification about the material, Q235B can be used instead of A36. And Shanghai All-Win Iron & Steel company has thousands of stocked Q235B plates, round bars, profiles etc. 


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