Chemical composition and mechanical properties of SA738 Gr-B, an American grade of  pressure vessel steel.

SA738 Gr-B Approximate Grade Lookup Table

SA738 Gr-B Chemical Composition

C① ≤0.20
Mn Smelting Analysis ≤1.5in.(40mm) 0.90-1.50
>1.5-2.0in.(40-50mm) 0.90-1.50
>2.0-2.5in.(50-65mm) 0.90-1.50
>2.5in.(65mm) 0.90-1.60
Finished Product Analysis ≤1.5in.(40mm) 0.84-1.62
>1.5-2.0in.(40-50mm) 0.84-1.62
>2.0-2.5in.(50-65mm) 0.84-1.62
>2.5in.(65mm) 0.84-1.72
P① ≤0.025
S① ≤0.025
Si Smelting Analysis 0.15-0.55
Finished Product Analysis 0.13-0.60
Cu Smelting Analysis ≤0.35
Finished Product Analysis ≤0.38
Ni Smelting Analysis ≤0.60
Finished Product Analysis ≤0.63
Cr Smelting Analysis ≤0.30
Finished Product Analysis ≤0.34
Mo Smelting Analysis ≤1.5in.(40mm) ≤0.20
>1.5in.(40mm) ≤0.30
Finished Product Analysis ≤1.5in.(40mm) ≤0.21
>1.5in.(40mm) ≤0.33
V Smelting Analysis ≤0.07②
Finished Product Analysis ≤0.08②
Nb Smelting Analysis ≤0.04②
Finished Product Analysis ≤0.05②
Nb+V Smelting Analysis ≤0.08②
Finished Product Analysis ≤0.10②
Ti ...
B ...
Ti ...

①Both smelting analysis and finished product analysis are applicable.

②Vanadium and niobium can only be added after consultation and agreement between the steel plate manufacturer and the purchasing party.

SA738 Gr-B Mechanical Properties

Tensile strength,(MPa)
≤1.5in.(40mm) 585-705
>1.5in.(40mm)-2.0in.(50mm) 585-705
>2.0in.(50mm)-2.5in.(65mm) 585-705
>2.5in.(65mm)-4in.(100mm) 585-705
>4in.(100mm) 585-705
Yield strength,(MPa)
≤1.5in.(40mm) 415
>1.5in.(40mm)-2.0in.(50mm) 415
>2.0in.(50mm)-2.5in.(65mm) 415
>2.5in.(65mm)-4in.(100mm) 415
>4in.(100mm) 415
Gauge length 2in. (50mm) elongation, % ②≥
≤1.5in.(40mm) 20
>1.5in.(40mm)-4in.(100mm) 20
>4in.(100mm) 20

①Not allowed

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