Chemical composition and mechanical properties of 15MnNiNbDR, a Chinese grade of cryogenic pressure vessel steel.
15MnNiNbDR Approximate Grade Lookup Table

15MnNiNbDR Chemical Composition

Grade Chemical Composition(Quality Fraction)/%
C Si Mn Ni Mo V Nb Altᵃ N P S
15MnNiNbDR ≤0.18 0.15~0.50 1.20~1.60 0.30~0.70 ≤0.08 一 0.015~0.040 一 ≤0.012 ≤0.020 ≤0.008
ᵃ When acid-soluble aluminum (Als) is used instead of Alt, the Al content should not be less than 0.015%; when Nb+V+Ti in the steel is ≥0.015%, the Al content is not required.

15MnNiNbDR 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 fracture A/% Temperature℃ Impact absorption energy KV₂/J
≥ ≥
15MnNiNbDR Normalizing or
Normalizing and Tempering		 6～16 530～630 370 20 -50 60 D=3a
>16～36 530～630 360
>36～60 520～620 340