Chemical Composition
| Element |
Composition, % |
| Carbon |
0.35 max |
| Manganese |
0.60 - 1.05 |
| Phosphorus |
0.035 max |
| Sulfur |
0.040 max |
| Silicon |
0.10 - 0.35 |
| Copper |
0.40 max [Note B] |
| Nickel |
0.40 max [Note B] |
| Chromium |
0.30 max [Note B, C] |
| Molybdenum |
0.12 max [Note B, C] |
| Vanadium |
0.08 max |
Notes
A : For each reduction of 0.01 % below the specified carbon maximum (0.35 %), an increase of 0.06 % manganese above the specified maximum (1.05 %) will be permitted up to a maximum of 1.65 %.
B : The sum of copper, nickel, chromium, molybdenum and vanadium shall not exceed 1.00 %.
C : The sum of chromium and molybdenum shall not exceed 0.32 %.
Mechanical Properties
| Property |
Value |
| Tensile Strength, min, ksi |
70.00 |
| Yield Strength, min, ksi [Note A] |
36.00 |
| Elongation in 2 inch. |
Round Specimen |
22.00 |
| Strip Specimen 5/16" and Over |
30.00 |
| Strip Specimen, Smaller sizes |
See next table |
| Reduction of Area, min, % [Note B] |
30.00 |
| Hardness, HWB, max |
187 |
Notes :
A : Determined by either the 0.2 % offset method or the 0.5 % extension-under-load method.
B : For round specimen only.
Heat Treatment
- Heat treatment is not a mandatory requirement of this
specification except for the following piping components:
- Flanges above Class 300,7
- Flanges of special design where the design pressure at
the design temperature exceeds the pressure-temperature ratings of Class 300, Group 1.1,
- Flanges of special design where the design pressure or
design temperature are not known,
- Piping components other than flanges which meet
both of the following criteria: (1) over NPS 4 and (2) above
Class 300, and
- Piping components of Special Class8 other than
flanges which meet both of the following criteria: (1) over NPS
4 and (2) when the working pressure at the operating temperature exceeds the tabulated values for Special Class 300, Group 1.1.
Heat treatment, when required by 6.1 shall be annealing,
normalizing, or normalizing and tempering or quenching and
tempering in accordance with Specification A961/A961M.
- Quenching shall consist of either (1) fully austenitizing the forgings followed by quenching in a suitable liquid medium or (2) using a multiple stage procedure whereby the forgings are first fully austenitized and rapidly cooled, then reheated to partially reaustenitize, followed by quenching in a suitable liquid medium. All quenched forgings shall be tempered as prescribed in Specification A961/A961M.
| Wall Thickness |
Elongation in 2 inch, min, % |
| 5/16 |
30.00 |
| 9/32 |
28.50 |
| 1/4 |
27.00 |
| 7/32 |
25.50 |
| 3/16 |
24.00 |
| 5/32 |
22.50 |
| 1/8 |
21.00 |
| 3/32 |
19.50 |
| 1/16 |
18.00 |
Referenced Documents
|
ASTM A961/A961M |
specification covers a group of common requirements that shall apply to steel flanges, forged fittings, valves, and parts for piping applications.
|
|
ASTM A266/A266M |
Specification for Carbon Steel Forgings for Pressure Vessel Components.
|
|
ASTM A675/A675M |
Specification for Steel Bars, Carbon, Hot Wrought, Special Quality, Mechanical Properties.
|
|
ASTM A696 |
Specification for Steel Bars, Carbon, Hot-Wrought or Cold-Finished, Special Quality, for Pressure Piping Components.
|
|
ASTM A788/A788M |
Specification for Steel Forgings, General Requirements.
|
|
ASTM A961/A961M |
Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications.
|
|
MSS SP 44 |
Standard for Steel Pipe Line Flanges.
|
|
ASME B16.5 |
Dimensional Standards for Steel Pipe Flanges and Flanged Fittings.
|
|
ASME B16.9 |
Wrought Steel Buttwelding Fittings.
|
|
ASME B16.10 |
Face-to-Face and End-to-End Dimensions of Ferrous Valves.
|
|
ASME B16.11 |
Forged Steel Fittings, Socket Weld, and Threaded
|
|
ASME B16.34 |
Valves-Flanged, Threaded and Welding End
|
|
ASME B16.47 |
Large Diameter Steel Flanges.
|
|
API-600 |
Flanged and Butt-Welding-End Steel Gate Valves.
|
|
API-602 |
Compact Design Carbon Steel Gate Valves for Refinery Use.
|
