|
ASTM A320
Studs Specification-NINGBO BOLT |
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ASTM A320 Studs Specification
The ASTM A320
specification covers alloy steel and Stainless Steel stud bolts materials for
low-temperature service.
Each alloy
under ASTM A320 shall conform to prescribed chemical requirements. The material,
as represented by the tension specimens, shall conform to specific requirements
in terms of tensile strength, yield strength, elongation, and hardness. The stud
bolt material shall meet the prescribed impact energy absorption requirements
and the target test temperature.
According to
the ASTM A320 specification, manufacturers shall execute at least the following
mechanical tests on the material: impact test, tension test, and hardness test.
The most
common stud bolts materials under ASTM A320 are listed below (low-temperature
service):
-
ASTM A320
L7: Alloy steel, AISI 4140/4142 Quenched and tempered
-
ASTM A320
L7M
-
ASTM A320
L43: Alloy steel, AISI 4340 Quenched and tempered
-
ASTM A320
B8 Class 1: Stainless steel, AISI 304, carbide solution treated
-
ASTM A320
B8A
-
ASTM A320
B8T
-
ASTM A320
B8TA
-
ASTM A320
B8C
-
ASTM A320
B8M: Class 1 Stainless steel, AISI 316, carbide solution treated
-
ASTM A320
B8MA
-
ASTM A320
B8cl2: Stainless steel, AISI 304, carbide solution treated, strain hardened
-
ASTM A320
B8Mcl2: Stainless steel, AISI 316, carbide solution treated, strain hardened
ASTM
A320 Stud Bolts: Mechanical Properties
|
ASTM A320
Grade |
Diameter |
Tensile, KSI,
min |
Yield, KSI,
min |
Charpy Impact
20-ft-LBF @ temp |
Elong, %, min |
RA, %, min |
|
ASTM A320
Grade L7 |
Up to 21⁄2 |
125 |
105 |
-150∼ F |
16 |
50 |
|
ASTM A320
Grade L43 |
Up to 4 |
125 |
105 |
-150∼ F |
16 |
50 |
|
ASTM A320
Grade B8 Class 1 |
All |
75 |
30 |
N/A |
30 |
50 |
|
ASTM A320
Grade B8M Class 1 |
All |
75 |
30 |
N/A |
30 |
50 |
|
ASTM A320
Grade B8 Class 2 |
Up to 3⁄4 |
125 |
100 |
N/A |
12 |
35 |
|
7⁄8 每 1 |
115 |
80 |
N/A |
15 |
35 |
|
11⁄8 每 11⁄4 |
105 |
65 |
N/A |
20 |
35 |
|
13⁄8 每 11⁄2 |
100 |
50 |
N/A |
28 |
45 |
|
ASTM A320
Grade B8M Class 2 |
Up to 3⁄4 |
110 |
95 |
N/A |
15 |
45 |
|
7⁄8 每 1 |
100 |
80 |
N/A |
20 |
45 |
|
11⁄8 每 11⁄4 |
95 |
65 |
N/A |
25 |
45 |
|
13⁄8 每 11⁄2 |
90 |
50 |
N/A |
30 |
45 |
STUD
BOLTS AND NUTS SELECTION (SERVICE vs. GRADE)
The material to use for stud bolts depends on multiple factors, the main ones
are the material of the flanges and the pipeline design temperature:
|
DESIGN |
FLANGE
MATERIAL |
STUD BOLT |
HEAVY HEX
STEEL NUTS |
|
TEMPERATURE |
|
-195∼ to
102∼C |
ASTM A 182
Gr. F304, F304L, F316, F316L, F321, F347 |
A320 Gr. B8
Class 2 |
A194 Gr. 8A |
|
-101∼ to
-47∼C |
ASTM A 350
Gr. LF3 |
A 320 Gr.
L7 |
A 194 Gr. 7 |
|
-46∼ to
-30∼C |
ASTM A 350
Gr. LF2 |
A 320 Gr.
L7 |
A 194 Gr. 7 |
|
-29∼ to
427∼C |
ASTM A 105 |
A 193 Gr.
B7 |
A 194 Gr.
2H |
|
428∼ to
537∼C |
ASTM A 182
Gr. F11, F22 |
A 193 Gr.
B16 |
A 194 Gr.
2H |
|
538∼ to
648∼C |
ASTM A182
Gr. F11, F22 |
A 193 Gr.
B8 Class 1 |
A 194 Gr.
8A |
|
649∼ to
815∼C |
ASTM A182
Gr. F304 H, F316 H |
A 193 Gr.
B8M Class 1 |
A 194 Gr.
8A |
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