This specification covers molybdenum-alloy steel plates, intended particularly for welded boilers and other pressure vessels.Plates under this specification are available in three grades having different strength levels.The maximum thickness of plates is limited only by the capacity of the composition to meet the specified mechanical property requirements; however, current practice normally limits the maximum thickness of plates furnished under the specification.
| Grades | Description |
|---|---|
| Grade A | - |
| Grade B | - |
| Grade C | - |
| Grade | Carbon | Manganese | Phosphorus,max | Sulfur,max | Silicon | Nickel | |||
|---|---|---|---|---|---|---|---|---|---|
| Up to 1 in. [25 mm] incl, in thickness | Over 1 in. to 2 in. [50 mm] incl, in thickness | Over 2 in. to 4 in. [100 mm] incl, in thickness | Over 4 in. [100 mm] in thickness | ||||||
| Grade A | 0.18 | 0.21 | 0.23 | 0.25 | 0.98 | 0.025 | 0.025 | 0.13–0.45 | 0.41–0.64 |
| Grade B | 0.20 | 0.23 | 0.25 | 0.27 | 0.98 | 0.025 | 0.025 | 0.13–0.45 | 0.41–0.64 |
| Grade C | 0.23 | 0.26 | 0.28 | 0.28 | 0.98 | 0.025 | 0.025 | 0.13–0.45 | 0.41–0.64 |
| Grades |
Tensile strength,min: ksi [MPa] |
Yield strength,min: ksi [MPa] |
Elongation in 8 in. [200 mm] min, %A | Elongation in 2 in. [50 mm] min, %A,B |
|---|---|---|---|---|
| Grade A and D | 65–85 [450–585] | 37 [255] | 19 | 23 |
| Grade B and E | 70–90 [485–620] | 40 [275] | 17 | 21 |
| Grade F | 75–95 [515–655] | 43 [295] | 16 | 20 |