ASTM A517 Grades B and F are both high-strength, quenched and tempered alloy steel plates for fusion-welded pressure vessels, but differ in specific chemical composition (especially alloying elements like Molybdenum, Chromium) and impact toughness requirements, with Grade F generally offering higher toughness and often used for very thick plates, while Grade B (and others like A, E, H) offer excellent strength and weldability, all conforming to ASTM A517 for demanding applications like boilers and storage tanks.
A517 grade B Chemical Composition
A517 grade B Chemical Composition | |||||
Grade | The Element Max (%) | ||||
C | Si | Mn | P | S | |
A517 grade B | 0.13-0.23 | 0.13-0.37 | 0.64-1.10 | 0.035 | 0.035 |
Cr | Mo | B | Ti | V | |
0.36-0.69 | 0.12-0.28 | 0.0005-0.005 | 0.01-0.05 | 0.02-0.09 | |
A517 grade F Chemical Composition
A517 grade F Chemical Composition | ||||||
Grade | The Element Max (%) | |||||
C | Si | Mn | P | S | Cu | |
A517 grade F | 0.08-0.22 | 0.13-0.37 | 0.55-1.10 | 0.035 | 0.035 | 0.12-0.53 |
Cr | Mo | B | V | Ni |
| |
0.36-0.69 | 0.36-0.64 | 0.0005-0.006 | 0.02-0.09 | 0.67-1.03 |
| |
A517 grade F Mechanical Property
Grade |
| A517 grade F Mechanical Property | ||
Thickness | Yield | Tensile | Elongation | |
A517 grade F | mm | Min Mpa | Mpa | Min % |
6-65 | 690 | 795-930 | 16% | |
65-150 | 620 | 725-930 | 14% | |
A517 grade B Mechanical Property
Grade |
| A517 grade B Mechanical Property | ||
Thickness | Yield | Tensile | Elongation | |
A517 grade B | mm | Min Mpa | Mpa | Min % |
6-65 | 690 | 795-930 | 16% | |
65-150 | 620 | 725-930 | 14% | |
Key Similarities:
Standard: Both fall under ASTM A517, for high-strength, quenched & tempered alloy steel plates.
Application: Used in fusion-welded boilers and other pressure vessels.
Heat Treatment: Both undergo quenching and tempering for enhanced strength.
High Strength: Both offer high tensile and yield strength, typically 100 ksi minimum yield for thinner plates.
Key Differences (General Comparison):
Chemical Composition: Specific alloy content (Cr, Mo, V, B, Ti) varies by grade, impacting properties like weldability and toughness.
Toughness: Grade F is known for its superior Charpy V-notch impact toughness, making it suitable for severe service, while Grade B has strong lateral expansion requirements.
Thickness: Grade F is often used for very thick sections (up to 2.5 inches or more), whereas Grade B might be for slightly thinner sections, though both can be produced thick.
