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

Table 1  Chemical Composition

Grade Chemical Composition(Quality Fraction)/%
C Si Mn Cu Ni Cr Mo Nb V Ti Altb P S Others
15CrMoR 0.08~0.18 0.15~0.40 0.40~0.70 ≤0.30 ≤0.30 0.80~1.20 0.45~0.60 　 　 　 　 ≤0.025 ≤0.010 　

7.1.6 The content of residual elements chromium, nickel, and copper should not exceed 0.30% each, and molybdenum should not exceed 0.080%, with the total content of these elements not exceeding 0.70%. Analysis is not required if the supplier can guarantee this.
7.1.8  The permissible deviation of the chemical composition of finished steel products shall comply with the provisions of CB/T 713.1.
7.1.9  For a comparison of similar grades with relevant international standards, please refer to Appendix A.

Table 2  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/% Tmeperature/℃ Impact absorption energy KV2
≥ 　 ≥
15CrMoR Normalizing+Tempering 6～60 450～590 295 19 20 47 D=3a
>60～100 275
>100～200 440～580 255

Note: D is the diameter of the bending indenter; b is the width of the sample; a is the thickness of the sample.
When the yielding phenomenon is not obvious, the specified plastic elongation strength Rp0.2 can be used instead.

Table 3  High temperature mechanical properties

Grade Thickness/mm Test temperature/℃
100 150 200 250 300 350 400 450 500
ReLᵃ( or Rp0.2)/MPa,≥
15CrMoR >20～60 270 255 240 225 210 200 189 179 174
>60～100 250 235 220 210 196 186 176 167 162
>100～200 235 220 210 199 185 175 165 156 150

ᵃ When the yielding phenomenon is not obvious, the specified plastic elongation strength Rp0.2 can be used instead.