Reg. 38
MATERIALS OF CONSTRUCTION
COLD DRAWN SEAMLESS CARBON STEEL BOILER AND SUPERHEATER TUBES FOR
DESIGN METAL TEMPERATURES NOT EXCEEDING 454°C (850°F).
Tensile and Hardness Tests |
The test
specimen shall comply with the following requirements.
The hardness test may be carried out on the wall cross
section or on a flat on the outside surface of the tube sample.
|
Grade
|
Yield
Strength Mpa
(kg./mm2)
min
|
Tensile
Strength Mpa
(kg/mm2) min
|
%
Elongation on
GL
= 50 mm min
|
Hardness
(max)
HRB
HB
|
|
TA
|
80(18.3)
|
325(33.1)
|
35
|
77
|
137
|
|
TB
|
255(26.1)
|
415(42.2)
|
30
|
79
|
143
|
|
TC
|
275(28.2)
|
485(49.3)
|
30
|
89
|
179
|
Note.-
For longitudinal strip tests a deduction in percentage elongation
1.5% shall be made for each 0.8 mm decrease in wall thickness under 8mm from the minimum
elongation value requirement. |
