A36, SS400 and Q235 chemical composition comparison table

1. The standard-making party is different from that A36 is the material of American standard ASME standard (equivalent to ASTM specification), SS400 is the material of Japanese standard JIS G3101 (rolled steel for common structure), and Q235 is the material of national standard GB700. GB700: Q235 JIS G3101: SS400 ASME: A36

2. Comparison table of chemical composition of materials with different A36, SS400 and Q235 chemical composition. Steel grade chemical composition mass fraction (%) C (≤) Mn (≤) Si (≤) S (≤) P (s) Cu (≤)

< > ASTMA36  0.26  0.40  0.050  0.040  0.2 min

CHINAQ235-A  0.14~0.22  0.3~0.65  0.30  0.050  0.045

CHINAQ235-B  0.12~0.20  0.30~0.70  0.30  0.045  0.045

JISSS400-- 0.050  0.050

The content of Mn element in A36 is not used due to the difference of plate thickness (or round steel diameter), and the content of Mn element is not included for those below 20mm. Q235 requires the content of C, Si, Mn. S, P and other elements, but SS400 requires that S and P be less than 0.050.

3. The tensile strength of A36 with different mechanical properties is 58~80 Ksi (about 400~550MPa), and the yield strength is 36 Ksi (about 250MPa); The tensile strength of Q235 is 370~500 MPa, and the yield strength is 235 MPa; The tensile strength of SS400 is 400~510 MPa, and the yield strength is 245 MPa (the mechanical properties of SS400 and Q235 are based on the steel plate thickness less than 16 mm.) From the above data, it can be seen that the materials of ASME A36 and Chinese Q235 are named based on the yield strength of the material, while SS400 is named based on the tensile strength of the material. From the analysis of mechanical properties of the material, A36 is equivalent to SS400, while Q235 is a little worse.

4. Replacement of A36, SS400 and Q235 Although the mechanical properties of Q235 materials are worse than those of A36 and SS400 materials, in the actual operation process, as long as the owner has no clear requirements, the three materials can often be substituted for each other.

If we only compare the mechanical properties of materials, the author thinks that the mechanical properties of A36 and SS400 are similar to those of high-quality carbon structural steel 20 #. The tensile strength of 20 # steel is not less than 410, and the yield strength is not less than 245, which is similar to the mechanical properties of A36 and SS400.