SPECIFICATION FOR CARBON STEEL FORGINGS FOR PIPING APPLICATIONS
(Identical with ASTM Specification A105/A105M-21 except for addition of Footnote A call out next to vanadium composition limit in Table 1 and deletion of (mm) from the thickness variable (T) in Table 3 Note minimum elongation formula.)
1. Scope
1.1 This specification covers forged carbon steel piping components for ambient- and higher-temperature service in pressure systems. Included are flanges, fittings, valves, and similar parts ordered either to dimensions specified by the purchaser or to dimensional standards such as the MSS, ASME, and API specifications referenced in Section 2. Forgings made to this specification are limited to a maximum weight of 10 000 lb [4540 kg]. Larger forgings may be ordered to Specification A266/A266M. Tubesheets and hollow cylindrical forgings for pressure vessel shells are not included within the scope of this specification. Although this specification covers some piping components machined from rolled bar and seamless tubular products (see 5.2), it does not cover raw material produced in these product forms.
1.2 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.
1.3 Specification A266/A266M covers other steel forgings and Specifications A675/A675M and A696 cover other steel bars.
1.4 This specification is expressed in both inch-pound units and SI units. However, unless the order specifies the applicable "M" specification designation (SI units), the material shall be furnished to inch-pound units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. Note 1 - The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as "nominal diameter," "size," and "nominal size."
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 In addition to those reference documents listed in Specification A961/A961M, the following list of standards apply to this specification:
2.2 ASTM Standards:
- A266/A266M Specification for Carbon Steel Forgings for Pressure Vessel Components
- A675/A675M Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality, Mechanical Properties
- A696 Specification for Steel Bars, Carbon, Hot-Wrought or Cold-Finished, Special Quality, for Pressure Piping Components
- A788/A788M Specification for Steel Forgings, General Requirements
- A961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications
2.3 MSS Standards:
- SP 44 Standard for Steel Pipe Line Flanges
2.4 ASME Standards:
- B16.5 Dimensional Standards for Steel Pipe Flanges and Flanged Fittings
- B16.9 Wrought Steel Buttwelding Fittings
- B16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves
- B16.11 Forged Steel Fittings, Socket Weld, and Threaded
- B16.34 Valves - Flanged, Threaded and Welding End
- B16.47 Large Diameter Steel Flanges
2.5 ASME Boiler and Pressure Vessel Code:
- Section IX
2.6 API Standards:
- API-600 Flanged and Butt-Welding-End Steel Gate Valves
- API-602 Compact Design Carbon Steel Gate Valves for Refinery Use
3. Terminology
3.1 Definitions - For definitions of other terms used in this specification, refer to Specification A961/A961M.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 heaviest cross-section, n - maximum heat treated thickness of the production forging.
4. Ordering Information
4.1 See Specification A961/A961M.
4.1.1 Additional requirements (see 14.2).
5. General Requirements
5.1 Product furnished to this specification shall conform to the requirements of Specification A961/A961M, including any supplementary requirements that are indicated in the purchase order. Failure to comply with the requirements of Specification A961/A961M constitutes nonconformance with this specification. In case of a conflict between the requirements of this specification and Specification A961/A961M, this specification shall prevail.
5.2 Except as permitted by Section 6 in Specification A961/A961M, the finished product shall be a forging as defined in the Terminology Section of Specification A788/A788M.
6. Heat Treatment
6.1 Heat treatment is not a mandatory requirement of this specification except for the following piping components:
6.1.1 Flanges above Class 300,
6.1.2 Flanges of special design where the design pressure at the design temperature exceeds the pressure-temperature ratings of Class 300, Group 1.1,
6.1.3 Flanges of special design where the design pressure or design temperature are not known,
6.1.4 Piping components other than flanges which meet both of the following criteria: (1) over NPS 4 and (2) above Class 300, and
6.1.5 Piping components of Special Class 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.
6.2 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. After hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the transformation range.
6.2.1 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.
7. Chemical Composition
7.1 The steel shall conform to the chemical requirements specified in Table 1.
7.2 Steels to which lead has been added shall not be used.
| 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 maxA |
| Nickel | 0.40 maxA |
| Chromium | 0.30 maxA,B |
| Molybdenum | 0.12 maxA,B |
| Vanadium | 0.08 maxA |
Note 1 - 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 %.
The sum of copper, nickel, chromium, molybdenum and vanadium shall not exceed 1.00 %.
The sum of chromium and molybdenum shall not exceed 0.32 %.
8. Mechanical Properties
8.1 The material shall conform to the mechanical property requirements prescribed in Table 2 and Table 3.
8.2 For normalized, normalized and tempered, or quenched and tempered forgings, the central axis of the test specimen shall be taken at least ¼ T from the nearest surface as-heat-treated, where T is the maximum heat-treated thickness of the represented forging. In addition, for quenched and tempered forgings, the midlength of the test specimen shall be at least T from all other surfaces as-heat-treated, exclusive of the T dimension surfaces. When section thickness does not permit this positioning, the test specimen shall be positioned as near as possible to the prescribed location.
8.3 Tension Tests:
8.3.1 One tension test shall be made for each heat of as-forged components.
8.3.2 One tension test shall be made from each heat-treating charge. If more than one heat is included in such a charge, each heat shall be tested.
8.3.2.1 When forgings of different shapes are included in the same heat-treating charge, the test specimen shall be obtained from the heaviest cross-section of the thickest forging, except for hubbed flanges (see 8.3.3). The test specimen shall represent all forgings from the same heat and heat-treating charge whose maximum thicknesses do not exceed the thickness of the test forging.
8.3.2.2 When the heat-treating temperatures are the same and the furnaces (either batch or continuous type) are controlled within ±25 °F [±14 °C] and equipped with recording pyrometers so that complete records of heat treatment are available, then one tension test from each heat is required instead of one test from each heat in each heat-treatment charge. The test specimen material shall be included with a furnace charge.
8.3.3 Testing shall be performed as specified in Specification A961/A961M. The largest feasible round specimen shall be used except when hollow cylindrically shaped parts are machined from seamless tubulars. When hollow cylindrically shaped parts are machined from seamless tubular materials, strip tests may be used. The tension test specimen shall be obtained from a production forging, or from an integral prolongation representative of the hub location of a flange, or the heaviest cross section of a fitting, valve, or other part within the scope of this specification.
8.3.4 Forgings too small to permit obtaining a subsize specimen of 0.250 in. [6.35 mm] diameter or larger parallel to the dimension of maximum working, and produced in equipment unsuitable for the production of a separately forged test bar such as an automatic or semi-automatic press, may be accepted on the basis of hardness only. One percent of the forgings per lot, where a lot is the product from a heat, or, if heat treated, the product of a heat per furnace charge, or ten forgings, whichever is the lesser number, shall be selected at random, prepared, and tested using the standard Brinell test. The locations of the indentations shall be at the option of the manufacturer but shall be selected to be representative of the forging as a whole. One indentation per forging shall be required but additional indentations may be made to establish the representative hardness. The hardness of all forgings so tested shall be 137 to 197 HBW inclusive.
8.4 Hardness Tests:
8.4.1 Two hardness tests shall be made for each heat of as-forged components. When more than one forging is produced from each heat, a minimum of two forgings shall be tested with one reading from each forging. When only one forging is produced, it shall be tested in two locations.
8.4.2 Except when only one forging is produced, a minimum of two forgings shall be hardness tested per batch or continuous run as defined in 8.3.2.2 to ensure that forgings are within the hardness limits given in Table 2. When only one forging is produced, it shall be hardness tested in two locations to ensure it is within the hardness limits given in Table 2.
8.4.3 Testing shall be as specified in Specification A961/A961M. The purchaser may verify that the requirement has been met by testing at any location on the forging, provided such testing does not render the forging useless.
| Property < | Requirement |
|---|---|
| Tensile strength, min, ksi [MPa] | 70 [485] |
| Yield strength, min, ksi [MPa]R | 36 [250] |
| Elongation in 2 in. or 50 mm, min, %: | |
| Basic minimum elongation for walls 5/32 in. [7.9 mm] and over in thickness, strip tests | 30 |
| When standard round 2-in. or 50-mm gauge length or smaller proportionally sized specimen with the gauge length equal to 4D is used | 22 |
| For strip tests, a deduction for each 1/32-in. [0.8-mm] decrease in wall thickness below 5/32 in. [7.9 mm] from the basic minimum elongation of the percentage points of Table 3 | 1.50C |
| Reduction of area, min, %D | 30 |
| Hardness, HBW, max | 197 |
For small forgings, see 8.3.4. See Table 3 for computed minimum values. For round specimens only.
| Wall Thickness < | Elongation in 2 in. or 50 mm, min, % | |
|---|---|---|
| in. < | mm < | |
| 5/32 (0.312) | 7.9 | 30.00 |
| 9/64 (0.281) | 7.1 | 28.50 |
| 1/4 (0.250) | 6.4 | 27.00 |
| 7/32 (0.219) | 5.6 | 25.50 |
| 3/16 (0.188) | 4.8 | 24.00 |
| 5/32 (0.156) | 4.0 | 22.50 |
| 1/8 (0.125) | 3.2 | 21.00 |
| 3/32 (0.094) | 2.4 | 19.50 |
| 1/32 (0.062) | 1.6 | 18.00 |
Note - The above table gives the computed minimum elongation values for each 1/32-in. (0.8-mm) decrease in wall thickness. Where the wall thickness lies between two values shown above, the minimum elongation value is determined by the following equation: E = 48T + 15.00 where: E = elongation in 2 in. or 50 mm, %, and T = actual thickness of specimen, in.
9. Hydrostatic Tests
9.1 Such tests shall be conducted by the forging manufacturer only when Supplementary Requirement S7 in Specification A961/A961M is specified.
10. Retreatment
10.1 If the results of the mechanical tests do not conform to the requirement specified, the manufacturer may heat treat or reheat treat the forgings as applicable and repeat the test specified in Section 8.
11. Surface Finish, Appearance, and Corrosion Protection
11.1 The requirements of Specification A961/A961M apply to forgings and finished parts.
12. Repair by Welding
12.1 Repair of defects by the manufacturer is permissible for forgings made to dimensional standards such as those of ASME or for other parts made for stock by the manufacturer. Prior approval of the purchaser is required to repair-weld special forgings made to the purchaser's requirements.
12.2 Weld repairs shall be made by a process that does not produce undesirably high levels of hydrogen in the welded areas.
12.3 All forgings repaired by welding shall be post-weld heat treated between 1100 °F [593 °C] and the lower transformation temperature for a minimum of ½ h/in. [½ h/25.4 mm] of maximum section thickness, or alternatively annealed, normalized and tempered, or quenched and tempered. If the forging was not previously heat treated, the original tempering temperature was exceeded, or the forging was fully heat treated in the post weld cycle, then the forging shall be tested in accordance with Section 8 on completion of the cycle.
12.4 The mechanical properties of the procedure qualification weldment shall, when tested in accordance with Section IX of the ASME Boiler and Pressure Vessel Code, conform with the requirements listed in Table 2 for the thermal condition of repair-welded forgings.
13. Rejection and Rehearing
13.1 Each forging that develops injurious defects during shop working or application shall be rejected and the manufacturer notified.
14. Certification
14.1 Identification Marking - For forgings made to specified dimensions, when agreed upon by the purchaser, and for forgings made to dimensional standards, application of identification marks as required in Specification A961/A961M shall be the certification that the forgings have been furnished in accordance with the requirements of this specification.
14.2 Test Reports - The manufacturer shall also provide the following, where applicable:
14.2.1 Type heat treatment, Section 6,
14.2.2 Tensile property results, Section 8 (Table 2), report the yield strength and tensile strength, in ksi [MPa], elongation and reduction in area, in percent; and, if longitudinal strip tension specimens are used, report the width of the gauge length,
14.2.3 Chemical analysis results, Section 7 (Table 1), reported results shall be to the same number of significant figures as the limits specified in Table 1 for that element,
14.2.4 Hardness results, Section 8 (Table 2), a minimum of two readings, and
14.2.5 Any supplementary testing required by the purchase order.
15. Product Marking
15.1 In addition to marking requirements of Specification A961/A961M, the following additional marking requirements shall apply:
15.1.1 If the forgings have been quenched and tempered, the letters "QT" shall be stamped on the forgings following this specification number.
15.1.2 Forgings repaired by welding shall be marked with the letter "W" following this specification number.
15.1.3 Plugs and bushings furnished to ASME B16.11 requirements are not required to be marked. Other parts ordered with no marking are by agreement between the purchaser and manufacturer.
15.1.4 When agreed upon between the purchaser and manufacturer and specified in the order, the markings shall be painted or stenciled on the fitting or stamped on a metal or plastic tag which shall be securely attached to the fitting.
15.2 Bar Coding - In addition to the requirements in Specification A961/A961M, bar coding is acceptable as a supplemental identification method. The purchaser may specify in the order a specific bar coding system to be used. The bar coding system, if applied at the discretion of the supplier, should be consistent with one of the published industry standards for bar coding. If used on small parts, the bar code may be applied to the box or a substantially applied tag.
SUPPLEMENTARY REQUIREMENTS
These requirements shall apply only when specified by the purchaser in the inquiry, contract, and order.
- S1. Hardness
- S1.1 The purchaser may check the hardness of any or all forgings supplied at any location on the forging and the hardness shall be 137 to 197 HBW. All forgings not within the specified hardness range shall be rejected.
- S2. Heat Treatment
- S2.1 All forgings shall be heat treated as specified by the purchaser.
- S2.2 When forgings not requiring heat treatment by 6.1 are supplied heat treated by purchaser request, the basis for determining conformance with Table 2 and Table 3 shall be hardness testing per 8.4 and either (1) tensile testing of heat treated forgings per 8.2, or (2) tensile tests from as-forged forgings or separately forged test blanks, as agreed upon between the supplier and purchaser.
- S2.3 When test reports are required, and tensile test results were obtained from as-forged forgings or as-forged test blanks, it shall be so indicated on the test report.
- S2.4 In addition to the marking required by Section 15, this specification shall be followed by the letter: A for annealed, N for normalized, NT for normalized and tempered, or QT for quenched and tempered, as appropriate.
- S3. Marking Small Forgings
- S3.1 For small products where the space for marking is less than 1 in. [25 mm] in any direction, test reports are mandatory and marking may be restricted to only such symbols or codes as are necessary to identify the parts with test reports.
- S3.2 When the configuration or size does not permit marking directly on the forging, the marking method shall be a matter of agreement between the manufacturer and the purchaser.
- S4. Carbon Equivalent
- S4.1 The maximum carbon equivalent, based on heat analysis, shall be 0.47 for forgings with a maximum section thickness of 2 in. or less, and 0.48 for forgings with a maximum section thickness of greater than 2 in.
- S4.2 Determine the carbon equivalent (CE) as follows: CE = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15
- S4.3 A lower maximum carbon equivalent may be agreed upon between the supplier and the purchaser.
16. Keywords
16.1 pipe fittings, steel; piping applications; pressure containing parts; steel flanges; steel forgings, carbon; steel valves; temperature service applications, elevated; temperature service applications, high
