standards:
China Classification Society and welding materials - China Classification Society (CCS)
Det Norske Veritas (DNV) specification - Det Norske Veritas (DNV)
Lloyd's Register of Shipping (LR) specification - UK Lloyd's Register (LR)
Lloyd's Register in Germany (GL) specification - Germany, Lloyds Register of Shipping (GL)
American Bureau of Shipping (ABS) specification - American Bureau of Shipping (ABS)
Bureau Veritas (BV) norm - Bureau Veritas (BV)
Italian classification society (RINA) norms - the Italian classification society (RINA)
Classification Society of Japan (NK) norms - the Japanese classification society (NK)
GB/T5312-- China's national standards
use:
for the boilers and superheaters and I,II-level pressure piping used in manufacturing seamless steel tubes.
produce steel grades:
320,360,410,460,490, etc.
Tolerance:
|
steel types
|
diameter (D)
|
pipe wall thickness (S)
|
|
tube cold-drawing
|
pipe outside diameter (mm)
|
allow deviation (mm)
|
pipe wall thickness (mm)
|
allow deviation (mm)
|
|
> 30 ~ 50
|
± 0.3
|
≤ 30
|
± 10%
|
|
> 50 ~ 219
|
± 0.8%
|
force properties:
|
standards
|
Grade
|
tensile strength (MPa)
|
yield strength (MPa)
|
elongation (%)
|
|
GB/T5312
|
320
|
320 ~ 410
|
≥ 195
|
≥ 25
|
|
360
|
360 ~ 480
|
≥ 215
|
≥ 24
|
|
410
|
410 ~ 530
|
≥ 235
|
≥ 22
|
|
460
|
460 ~ 580
|
≥ 265
|
≥ 21
|
|
490
|
490 ~ 610
|
≥ 285
|
≥ 21
|
chemical composition:
|
standards
|
Grade
|
chemical composition (%)
|
|
C
|
Si
|
Mn
|
P
|
S
|
|
GB/T5312
|
320
|
≤ 0.16
|
≤ 0.35
|
0.40 ~ 0.70
|
≤ 0.035
|
≤ 0.035
|
|
360
|
≤ 0.17
|
≤ 0.35
|
0.40 ~ 0.80
|
≤ 0.035
|
≤ 0.035
|
|
410
|
≤ 0.21
|
≤ 0.35
|
0.40 ~ 1.20
|
≤ 0.035
|
≤ 0.035
|
|
460
|
≤ 0.22
|
≤ 0.35
|
0.80 ~ 1.40
|
≤ 0.035
|
≤ 0.030
|
|
490
|
≤ 0.23
|
≤ 0.35
|
0.80 ~ 1.50
|
≤ 0.035
|
≤ 0.030
|
Note : residual element Cr ≤ 0.25%, Mo ≤ 0.10%, Ni ≤ 0.30%, Cu ≤ 0.30% of total ≤ 0.70%