Civil Engineering Reference
In-Depth Information
If the probability of exposure of the structure to fires is not negligible, relevant
accident-related design situations should be defined and evaluated. Damage result-
ing from fires and explosions should be provided for in the structure design.
Generally, conventional steel-framed structures with relatively small topside
structures that do not have enclosed compartments containing flammable fluids
or ignition sources do not require design against explosion. However, if explo-
sion studies of the topside indicate significant or unusual actions on the struc-
ture or indicate the need for specific support requirements to ensure that topside
integrity is maintained, then such actions or support requirements should be
provided for in the structure design.
2.9 MATERIAL STRENGTH
Steel should conform to a definite specification and to the minimum strength
level, group and class specified by the designer. Certified mill test reports or cer-
tified reports of tests made by the fabricator or a testing laboratory in accordance
with ASTM A6 or A20, as applicable to the specification listed in
Table 2.30
,
constitute evidence of conformity with the specification. Unidentified steel
should not be used.
2.9.1 Steel Groups
Steel may be grouped according to strength level and welding characteristics as
follows:
Group
I
are mild steels with specified minimum yield strengths of 279 MPa or
less. These steels may be welded by any of the welding processes described in
AWS D1.1.
●
TABLE 2.30
Steel Chemical Composition Based on ASTM
C
0.18% max
Mn
1.5% max
Nb
0.10% max
V
0.015% max
S
*
0.025% max
CE
**
0.42% max
*For plate designated on the order as Z grade, with through-thickness properties, sulfur content
should be limited to 0.008% max.
**Carbon equivalent (CE) should be based on product analysis and should be calculated using the
following equation:
Carbon equivalent (CE) = C + (Mn/6) + (Ni + Cu/15) + (Cr + Mo + V/5)
Search WWH ::
Custom Search