This specification covers minimum wall-thickness, seamless ferritic and austenitic steel for boiler and superheater tubes.
SIZE RANGE
Diameter : 1/8 in. (3.2 mm) in inside diameter to 5 in. (127 mm) in outside diameter
Minimum wall thickness : 0.015 to 0.500 in. (0.4 to 12.7 mm)
MANUFACTURE
Tubes shall be made by the seamless process and shall be either hot finished or cold finished, as specified.
All tubes shall be heat-treated.
CHEMICAL REQUIREMENTS
TENSILE REQUIREMENTS
| Grades | Tensile strength mini | Yield strength mini | Elongation mini (1) in 2 in. or 50 mm | Brinell hardness | |||||||||||||||||||||||||||||||||||
| ksi | MPa | ksi | MPa | % | maxi | ||||||||||||||||||||||||||||||||||
T2–T5–T5-T11–T17–T21–T22 18 Cr – 2 Mo | 60 | 415 | 30 | 205 | 30 | 163 | |||||||||||||||||||||||||||||||||
| 60 | 415 | 30 | 205 | 30 | 179 | ||||||||||||||||||||||||||||||||||
| 60 | 415 | 32 | 220 | 30 | 163 | ||||||||||||||||||||||||||||||||||
| 74 | 510 | 58 | 400 | 20 | 220 | ||||||||||||||||||||||||||||||||||
| 85 | 585 | 60 | 415 | 20 | 250 | ||||||||||||||||||||||||||||||||||
| 90 | 620 | 64 | 440 | 20 | 250 | ||||||||||||||||||||||||||||||||||
| 90 | 620 | 58 | 400 | 20 | 250 | ||||||||||||||||||||||||||||||||||
| 60 | 415 | 40 | 275 | 20 | 217 | ||||||||||||||||||||||||||||||||||
(1) Basic minimum elongation for walls 5/16 in. (7.9 mm) and over in thickness, longitudinal strip tests, and for all small sizes
in full section.
GENERAL REQUIREMENTS
To specification ASTM A 450 / A 450 M-96a.
