Chemical composition and mechanical properties of SA737Gr.C, an American grade of  pressure vessel steel.

SA737Gr.C Approximate Grade Lookup Table

SA737Gr.C Chemical Composition

Element Smelting Analysis,% Finished Product Analysis,%
C,≤ 0.22 0.24
Mn 1.15-1.50① 1.07-1.62
P,≤ 0.025 0.025
S,≤ 0.025 0.025
Si 0.15-0.50 0.10-0.55
V 0.04-0.11 0.03-0.12
Cb（Nb）②，≤ 0.05 0.05
N,≤ 0.03 0.03

①Under the condition that the carbon content in the smelting analysis does not exceed 0.18%, the maximum manganese content can be increased to 1.60% in the smelting analysis and to 1.72% in the finished product analysis.

②Cb and Nb are the same element, their names are interchangeable, and both names can be used in the A01 standard.

SA737Gr.B Mechanical Properties

Yield strength，≥，（MPa） 415
Tensile strength,（MPa） 550-690
Elongation① (gauge length 8 in. or 200 mm), ≥，% 18
Elongation① (gauge length 2 in. or 50 mm), ≥，% 23

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