Chemical composition and mechanical properties of SA387 Grade11, an American grade of  pressure vessel steel.

SA387 Grade11 Approximate Grade Lookup Table

SA387 Grade11 Chemical Composition

Element Analysis Category Grade11
C Smelting Analysis 0.05-0.17
Finished Product Analysis 0.04-0.17
Mn Smelting Analysis 0.40-0.65
Finished Product Analysis 0.35-0.73
P,≤ Smelting Analysis 0.025
Finished Product Analysis 0.025
S,≤ Smelting Analysis 0.025
Finished Product Analysis 0.025
Si Smelting Analysis 0.50-0.80
Finished Product Analysis 0.44-0.86
Cr Smelting Analysis 1.00-1.50
Finished Product Analysis 0.94-1.56
Mo Smelting Analysis 0.45-0.60
Finished Product Analysis 0.40-0.70
Ni Smelting Analysis ...
Finished Product Analysis ...
V Smelting Analysis ...
Finished Product Analysis ...
Nb Smelting Analysis ...
Finished Product Analysis ...
B,≤ᶜ ...
N Smelting Analysis ...
Finished Product Analysis ...
N/Al ...
Al,≤ᶜ ...
Ti,≤ᶜ ...
Zr,≤ᶜ ...
W,≤ᶜ ...
Cu,≤ᶜ ...
Sb,≤ᶜ ...
As,≤ᶜ ...
Sn,≤ᶜ ...

A:For steel plates with a thickness greater than 5 inches (125 mm), the carbon content in the finished product analysis should not exceed 0.17%.

B:Cb and Nb are interchangeable and commonly used names for the same element, and both names are applicable to the (ASTM) "A101" standard.

C:Both smelting analysis and finished product analysis are applicable.

SA387 Grade11 Mechanical Properties

Tensile properties of Class I steel plates

Tensile strength(MPa) 415-585
Yield strength(MPa) ≥240
Elongation (gauge length 8 in. or 200 mm), % ≥19
Elongation (gauge length 8 in. or 50 mm), % ≥22
Reduction of area,% ...

①For adjustments to elongation, please refer to the A20/A20M standard.

②Measurement using a round sample.

③Determination using flat specimens.

Tensile properties of Class II steel plates

Tensile strength(MPa) 515-690
Yield strength (0.2% residual deformation), MPa ≥ 310
Elongation (gauge length 8 in. or 200 mm), %≥ 18
Elongation (gauge length 8 in. or 50 mm), %≥ 22
Reduction of area,% ...

①Not applicable to annealed steel sheets

②For adjustments to elongation, please refer to the A20/A20M standard.

③Measurement using a round sample.

④Determination using flat specimens.

*Grade 91 steel plate is only applicable to Category 2 steel plates, see Section 1.3 — Translator's note