Chemical composition and mechanical properties of Q420DR, a Chinese grade of low-temperature pressure vessel steel.
Q420DR Approximate Grade Lookup Table

Chemical Composition

Grade Chemical Composition(Quality Fraction)/%
C Si   Mn Ni Mo V Nb Alt   N P S
Q420DR ≤0.20 0.15~0.50 1.30~1.70 0.30~0.80 ≤0.08 0.05~0.15 0.015~0.050 一 ≤0.020 ≤0.018 ≤0.008

Mechanical properties and processing properties

Grade Delivery status Thickness mm Tensile test Impact test 180°Bending test b=2a
Tensile strength Rm/MPa Lower yield strength
ReL/MPa		 Elongation after fractureA/% temperature℃ Impact absorption energy KV₂/J
≥ ≥
Q420DR Normalizing or
Normalizing + Tempering		 6～20 590～720 420 19 -40 60 D=3a
>20～30 570～700 400