Chemical composition and mechanical properties of SA387 Grade12, an American grade of pressure vessel steel.
SA387 Grade12 Approximate Grade Lookup Table
SA387 Grade12 Chemical Composition
| Element | Analysis Category | Grade12 | ||||||||
| 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 | 0.15-0.40 | ||||||||
| Finished Product Analysis | 0.13-0.45 | |||||||||
| Cr | Smelting Analysis | 0.80-1.15 | ||||||||
| Finished Product Analysis | 0.74-1.21 | |||||||||
| Mo | Smelting Analysis | 0.45-0.60 | ||||||||
| Finished Product Analysis | 0.40-0.65 | |||||||||
| 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 Grade12 Mechanical Properties
Tensile properties of Class I steel plates
| Tensile strength(MPa) | 380-550 | ||||||||||||
| Yield strength(MPa) | ≥230 | ||||||||||||
| Elongation (gauge length 8 in. or 200 mm), % | ≥18 | ||||||||||||
| 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) | 450-585 | ||||||||||||||
| Yield strength (0.2% residual deformation), MPa ≥ | 275 | ||||||||||||||
| Elongation (gauge length 8 in. or 200 mm), %≥ | 19 | ||||||||||||||
| 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