Chemical element composition of Chinese grade hot-rolled Q355B low-alloy high-strength structural steel
Q355B Approximate Grade Lookup Table

Table 1  Chemical Composition

Grade Chemical Composition（Quality Fraction） / %
Steel Grade Quality Grade Cᵃ Si Mn Pᶜ Sᶜ Nbᵈ Vᵉ Tiᵉ Cr Ni Cu Mo Nᶠ B
Thickness
≤40ᵇ ＞40 ≤
≤
Q355 B 0.24 0.55 1.6 0.035 0.035 - - - 0.3 0.3 0.4 - 0.012 -
a.For structural steel sections with a nominal thickness greater than 100mm, the carbon content can be determined through negotiation between the supplier and the buyer.
b.For steel with a nominal thickness greater than 30mm, the carbon content shall not exceed 0.22%.
c.For structural steel and bars, the upper limit for phosphorus and sulfur content can be increased by 0.005%.
d.The maximum percentage for Q390 and Q420 can reach 0.07%, while for Q460 it can reach 0.11%.
e.Up to 0.2%
f.If the acid-soluble aluminum (Als) content of the steel is not less than 0.015% or the total aluminum content is not less than 0.02%, or if other oxygen-fixing alloying elements are added, the nitrogen content is not limited, and the oxygen-fixing elements should be specified in the quality certificate.
g.Applicable only to structural steel and bars

Table 2  Tensile properties

Grade Upper yield strength ReHᵃ／MPA≥ Tensile strength Rm／MPA KV2 ( J)
Steel grade Quality
grade		 Nominal thickness or diameter／ｍｍ 20℃
≤16 ＞16~40 ＞40~63 ＞63~80 ＞80~100 ＞100~150 ＞150~200 ＞200~250 ＞250~400 ≤100 ＞100~150 ＞150~250 ＞250~400 Vertical Horizontal
Q355 B 355 345 335 325 315 295 285 275 - 470~630 450~600 450~600 - 34 27
A:When the yield strength is not obvious, the specified plastic elongation strength Rp0.2 can be used instead of the upper yield strength.
B:It is only applicable to steel plates of quality grade D.
C:Applicable only to structural steel and bars.

The grades and manufacturing standards that can be substituted for this Q355B sheet are as follows:ISO 630-2:2011 S355B、EN 10025-2:2004 S355JR