SPECIFICATION FOR CARBON AND LOW-ALLOY

01 STEEL FORGINGS, REQUIRING NOTCH TOUGHNESS

TESTING FOR PIPING COMPONENTS
SA-350 /SA-350M

(Identical with ASTM Specification A 350 /A 350M-00.)

1. Scope NOTE 1 — Refer to Test Methods and Definitions A 370 for notes
on significance of notched-bar impact testing.
1.1 This specification covers several grades of carbon
and low-alloy steel forged or ring-rolled flanges, forged
fittings and valves intended primarily for low-tempera-
ture service and requiring notch toughness testing. They 2. Referenced Documents
are made to specified dimensions, or to dimensional
2.1 ASTM Standards:
standards, such as the ASME and API Specifications
A 275 /A 275M Test Method for Magnetic Particle Exam-
referenced in Section 2. Although this specification
ination of Steel Forgings
covers some piping components machined from rolled
A 370 Test Methods and Definitions for Mechanical Test-
bar and seamless tubular materials (see 4.3.3), it does
ing of Steel Products
not cover raw material produced in these product forms.
A 751 Test Methods, Practices, and Terminology for
1.2 No limitation on size is intended beyond the Chemical Analysis of Steel Products
ability of the manufacturer to obtain the specified A 788 Specification for Steel Forgings, General Require-
requirements. However, Class 3 of Grade LF787 is ments
only available in the quenched-and-precipitation, heat- E 165 Test Method for Liquid Penetrant Examination
treated condition. E 381 Method of Macroetch Testing Steel Bars, Billets,
Blooms, and Forgings
1.3 Supplementary requirements are provided for use
when additional testing or inspection is desired. These 2.2 MSS Standard:
shall apply only when specified by the purchaser in MSS-SP 25 Standard Marking System for Valves, Fit-
the order. tings, Flanges and Unions

1.4 This specification is expressed in both inch- 2.3 ASME Standards:

pound units and in SI units. However, unless the order Section IX, Welding Qualifications, ASME Boiler and
specifies the applicable “M” specification designation Pressure Vessel Code
(SI units), the material shall be furnished to inch- B16.5 Steel Pipe Flanges and Flanged Fittings
pound units. B16.9 Factory-Made Wrought Steel Butt-Welding Fit-
tings
1.5 The values stated in either inch-pound units or B16.10 Face-to-Face and End-to-End Dimensions of Fer-
SI units are to be regarded separately as standard. rous Valves
Within the text, the SI units are shown in brackets. The B16.11 Forged Steel Fittings, Socket-Welding and
values stated in each system are not exact equivalents; Threaded
therefore, each system must be used independently of B16.30 Unfired Pressure Vessel Flange Dimensions
the other. Combining values from the two systems may B16.34 Valves—Flanged, Threaded, and Welding End
result in nonconformance with the specification. B16.47 Large Diameter Steel Flanges

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2.4 AWS Standards: 4.3.2 The finished product shall be a forging as

A 5.1 Mild Steel Covered Arc-Welding Electrodes defined in the Terminology section of Specification
A 5.5 Low-Alloy Steel Covered Arc-Welding Electrodes A 788.
2.5 API Standards: 4.3.3 Except for flanges of all types, hollow,
600 Steel Gate Valves with Flanged or Butt-Welding cylindrically shaped parts may be machined from rolled
Ends bar or seamless tubular materials provided that the
602 Compact Design Carbon Steel Gate Valves for Re- axial length of the part is approximately parallel to
finery Use the metal flow lines of the stock. Other parts, excluding
605 Large Diameter Carbon Steel Flanges flanges of all types, may be machined from hot-rolled
or forged bar up through and including NPS 4. Elbows,
return bends, tees, and header tees shall not be machined
directly from bar stock.
3. Ordering Information
3.1 It is the purchaser’s responsibility to specify in 4.4 Heat Treatment:
the purchase order all ordering information necessary 4.4.1 After hot working and before reheating for
to purchase the needed material. Examples of such heat treatment, the forging shall be allowed to cool
information include but are not limited to the following: substantially below the transformation range.

3.1.1 Quantity, 4.4.2 Forgings of grades other than Grade LF787

shall be furnished in the normalized, or in the normalized
3.1.2 Size and pressure class or dimensions (Toler- and tempered, or in the quenched and tempered condi-
ances and surface finishes should be included), tion described by the following procedures:
3.1.3 Specification number, grade, and class if 4.4.2.1 Normalize — Heat to a temperature that
applicable (The year date should be included), produces an austenitic structure, holding sufficient time
to attain uniform temperature throughout. Cool uni-
3.1.4 Supplementary requirements, and
formly in still air.
3.1.5 Additional requirements (See Table 1 foot-
4.4.2.2 Normalize and Temper — Subsequent
notes, 6.1.3.5, 8.1, 13.1, 13.2, and 14.2).
to normalize, reheat to 1100°F [590°C] minimum, hold-
ing at temperature a minimum of 30 min /in. [30 min /25
mm] of maximum thickness, but in no case less than
4. Manufacture 30 min. Cool in still air.
4.1 Melting Process — The steel shall be produced 4.4.2.3 Quench and Temper — The procedure
by any of the following primary processes; open-hearth, for quenching shall consist of either (1) fully austenitiz-
basic-oxygen, electric-furnace, or vacuum-induction ing the forgings followed by quenching in a suitable
melting (VIM). The primary melting may incorporate liquid medium or (2) using a multiple stage procedure
separate degassing or refining, and may be followed whereby the forging is first fully austenitized and rapidly
by secondary melting using electroslag remelting (ESR), cooled, then reheated to partially reaustenitize, followed
or vacuum-arc remelting (VAR). by quenching in a suitable liquid medium. All quenched
4.1.1 The steel shall be fully killed, fine-grain forgings shall be tempered by reheating to a temperature
practice. between 1100°F [590°C] and the lower transformation
temperature, holding at temperature a minimum of 30
4.1.2 The molten steel may be vacuum treated min /in. [30 min /25 mm] of maximum thickness but
prior to or during pouring of the ingot. in no case less than 30 min. Cool in still air.
4.2 Discard — A sufficient discard shall be made 4.4.3 Grade LF787 forgings shall be furnished
to secure freedom from injurious piping and undue in either the normalized-and-precipitation, heat-treated
segregation. condition or in the quenched-and-precipitation, heat-
4.3 Forging Process: treated condition. The heat treatment procedures shall
be as follows:
4.3.1 Material for forgings shall consist of ingots,
or forged, rolled, or strandcast blooms, billets, slabs, 4.4.3.1 Normalized-and-Precipitation Heat
or bars. Treated — Heat to a temperature in the range from

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1600 to 1725°F [870 to 940°C], hold at the temperature 6.1.1.1 The test specimen shall be obtained from
for a time sufficient to attain uniform temperature a rough or finished forging, or prolongation thereof.
throughout, soak at the temperature for not less than For forgings under 10 000 lbs, at time of heat treatment,
1
⁄2 h, and remove from the furnace and cool in air. it may be obtained from separately forged test blanks
Subsequently, heat to a temperature in the range from from the same heat of steel as the production forgings.
1000 to 1200°F [540 to 650°C], soak at the temperature The test blank shall be reduced by forging in a manner
for not less than 1⁄2 h, and cool at any convenient rate. similar to that for the products represented, and shall
receive approximately the same hot working and reduc-
4.4.3.2 Quenched-and-Precipitation Heat tion and the same heat treatment as the finished products
Treated — Heat to a temperature in the range from represented. The test material shall be treated in the
1600 to 1725°F [879 to 940°C], hold at the temperature same furnace at the same time as the forging it repre-
for a time sufficient to attain uniform temperature sents, subject to the requirements of 6.1.2.1.
throughout, soak at the temperature for not less than
1
⁄2 h and quench in a suitable liquid medium by 6.1.1.2 The test specimen shall represent all
immersion; reheat to a temperature in the range from forgings from the same heat and heat-treatment load
1000 to 1225°F [540 to 665°C], hold at the temperature whose maximum thicknesses do not exceed the thickness
for not less than 1⁄2 h, and cool at any convenient rate. of the test forging or blank by more than 1⁄4 in. [6 mm].

6.1.2 Number of Tests — One tension test at room

5. Chemical Composition
temperature shall be made in accordance with 6.1.1.2
5.1 Heat Analysis: from each heat in each heat-treatment load.
5.1.1 An analysis of each heat of steel shall be
made by the steel producer from samples taken prefera- 6.1.2.1 If heat treatment is performed in either
bly during the pouring of the heat. The results shall a continuous or a batch-type furnace controlled within
conform to Table 1. ±25°F [±14°C] of the required heat-treatment tempera-
ture and equipped with recording pyrometers so that
5.1.2 Steels to which lead has been added shall complete records of heat treatment are available and
not be used. if the same heat-treating cycles are used on the forgings
5.1.3 Intentional additions of copper, nickel, chro- represented by the tension test, then one tension test
mium, or molybdenum to Grades LF1, LF2, and LF6 from each heat shall be required, instead of one tension
are not permitted. Intentional additions of copper, chro- test from each heat in each heat treatment load in
mium, or molybdenum to Grades LF3 or LF5 are accordance with 6.1.1.2.
not permitted. Intentional additions of chromium or
molybdenum to Grade LF9 are not permitted. 6.1.3 Test Locations and Orientations — The test
specimen shall be removed from the heaviest section
5.2 Product Analysis — An analysis may be made of the forging or test blank, at locations described in
by the purchaser from a forging representing each heat 6.1.3.1, 6.1.3.2, 6.1.3.5, or as close to these locations
of steel. Samples for analysis shall be taken midway as practical, subject to forging size and geometry.
between center and surface of solid forgings, midway
between inner and outer surfaces of hollow forgings, 6.1.3.1 For forgings or test blanks having a
midway between center and surface of full-size prolon- maximum heat-treated thickness, T, of 2 in. [50 mm]
gations, or from broken mechanical test specimens. The or less, the longitudinal axis of the test specimen shall
chemical composition thus determined shall conform be taken at mid-thickness and its mid-length shall be
to Table 1, with the tolerances as stated in Table 2. at least 2 in. [50 mm] from a second heat-treated
5.3 Methods of Analysis — Test Methods, Practices, surface, exclusive of the T dimension surfaces. (This
and Terminology A 751 shall apply. is normally referred to as 1⁄2 T by 2 in. [50 mm]).

6.1.3.2 For forgings or test blanks having a

6. Mechanical Properties maximum heat-treated thickness, T, greater than 2 in.
[50 mm], the central axis of the test specimen shall
6.1 Tension Tests: be taken at least 1⁄4 T from the nearest heat-treated
6.1.1 Requirements — The material shall conform surface and at least T or 4 in. [100 mm], whichever
to requirements for tensile properties in Table 3. is less, from any second heat-treated surface.

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6.1.3.3 Metal Buffers — The required distances 6.2.1.1 The test specimens shall be machined
from heat treated surfaces may be obtained with metal from material obtained as in 6.1.
buffers instead of integral expansions. Buffer material
may be carbon or low alloy steel, and shall be joined 6.2.2 Number of Tests — Three specimens shall
to the forging with a partial penetration weld that seals constitute one test set. There shall be the same number
the buffered surface. Specimens shall be located at 1⁄2 of test sets as tension tests in 6.1.2.
in. [13 mm] minimum from the buffered surface of
the forging. Buffers shall be removed and the welded 6.2.3 Test Locations and Orientations — The test
areas subjected to magnetic particle test to assure specimen shall be located and oriented as described in
freedom from cracks unless the welded areas are com- 6.1.3. The area under the notch of the impact test
pletely removed by subsequent machining. specimen shall be used to locate the specimen with
respect to the second heat-treated surface. The base of
6.1.3.4 The test specimen shall have its longitudi- the notch shall be perpendicular to the nearest heat-
nal axis located parallel to the direction of major treated surface.
working of the forging or test blank.
6.2.4 Test Method — The notched bar impact test
6.1.3.5 With prior purchaser approval, tests may
shall be made in accordance with the procedure for
be taken at a depth (t) corresponding to the distance
the Charpy V-notch type test as described in Test
from the area of significant loading to the nearest heat-
Methods and Definitions A 370.
treated surface and at least twice this distance (2t)
from any second surface. However, the test depth shall 6.2.4.1 Standard size specimens shown in Fig.
not be nearer to one treated surface than 3⁄4 in. [19 11 of Test Methods and Definitions A 370 shall be
mm] and to the second treated surface than 11⁄2 in. used for the impact test. Where the material is of
[38 mm]. This method of test location would normally insufficient thickness, or the shape of the forging pre-
apply to contour-forged parts, or parts with thick cross- cludes standard size, the largest obtainable subsize
sectional areas where 1⁄4 T × T testing (6.1.3.2) is not specimen described in Test Methods and Definitions
practical. Sketches showing the exact test locations A 370 shall be used.
shall be approved by the purchaser when this method
is used. 6.2.4.2 Where subsize specimens are used and
6.1.4 Test Method — Testing shall be performed represent forged material with thicknesses equal to or
in accordance with Test Methods and Definitions A greater than 0.394 in. [10 mm], and where the largest
370. The test specimen shall be as large as is practicable obtainable specimen has a width along the notch of
and shall be machined to the form and dimensions of at least 8 mm, such specimen shall be tested at the
Fig. 5 of Test Methods and Definitions A 370. When temperature in Table 5. Where the largest obtainable
seamless tubular materials are used, testing shall be specimen has a width along the notch less than 8 mm,
performed on longitudinal specimens in accordance with the temperature for testing shall be lower than the
Annex A2, Steel Tubular Products, of Test Methods temperature in Table 5 by the amount shown in Table
and Definitions A 370. 7 for the actual specimen width tested.

6.2 Impact Test: 6.2.4.3 Where subsize specimens are used and
6.2.1 Requirements — The material shall conform represent forged material with thicknesses less than
to the requirements for impact properties in Table 4 0.394 in. [10 mm], and where the largest obtainable
when tested at the applicable standard temperature in specimen has a width along the notch of at least 80%
Table 5 within the limits of 6.2.4.2 and 6.2.4.3. When of the forging thickness, the specimen shall be tested at
subsize specimens are used, the impact energy values the temperature in Table 5. Where the largest obtainable
obtained shall conform to Table 6 at energy values specimen has a width along the notch of less than
proportional to standard size. Exceptions to this require- 80% of the material thickness, the temperature for
ment are permissible when Supplement S4 is specified testing shall be lower than the temperature in Table 5
by the purchaser. Impact tests may be made at tempera- by an amount equal to the difference (referring to Table
tures different from those in Table 5, provided that 7) between the temperature reduction corresponding
the test temperature is at least as low as the intended to the thickness of the material represented, and the
service temperature, and that the forging is suitably temperature reduction corresponding to the specimen
marked to identify the reported test temperature. width actually tested.

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6.3 Hardness Test: 8.4 Machining or Grinding Imperfections Not Classi-

6.3.1 Except when only one forging is produced, fied as Injurious — Surface imperfections not classified
a minimum of two forgings shall be hardness tested as injurious shall be treated as follows:
per batch or continuous run as defined in 6.1.2.1 to 8.4.1 Forgings showing seams, laps, tears, or slivers
ensure that hardness of the forgings does not exceed not deeper than 5% of the nominal wall thickness or
197 HB after heat treatment for mechanical properties. 1
⁄16 in. [1.6 mm], whichever is less, need not have these
The hardness measurements shall be made in accordance imperfections removed. If the imperfections require
with Test Methods and Definitions A 370. When only removal, they shall be removed by machining or
one forging is produced, it shall be hardness tested to grinding.
ensure that it meets the 197 HB maximum of this
specification. The purchaser may verify that this require- 8.4.2 Mechanical marks or abrasions and pits shall
ment has been met by testing at any location on the be acceptable without grinding or machining provided
forging, provided that such testing does not render the the depth does not exceed the limitations set forth in
forging useless. 8.2 and is not deeper than 1⁄16 in. [1.6 mm]. If such
imperfections are deeper than 1⁄16 in. [1.6 mm], but do
not encroach on the minimum wall thickness of the
forging, they shall be removed by grinding to sound
7. Hydrostatic Test
metal.
7.1 Forgings manufactured under this specification
8.4.3 When imperfections have been removed by
shall be capable of passing a hydrostatic test compatible
grinding or machining, the outside dimension at the
with the rating of the finished forging. Such tests shall
point of grinding or machining will be reduced by the
be conducted by the forging manufacturer only when
amount removed. Should it be impracticable to secure
Supplementary Requirement S9 is specified.
a direct measurement of wall thickness at the point of
grinding, or at imperfections not required to be removed,
the thickness shall be determined by deducting the
8. Workmanship, Finish, and Appearance amount removed by grinding, from the nominal finished
8.1 The forgings shall conform to the dimensions, wall thickness of the forging. The remainder shall not
tolerances, and finish as specified on the purchaser’s be less than the minimum specified or required wall
drawing or order. Unless otherwise specified in the thickness.
purchase order, the fittings shall be cleaned to remove
all scale and processing compounds prior to final surface
examination. The cleaning process shall not injure the 9. Retests
surface finish, material properties, or the metallurgical 9.1 If any test specimen shows flaws or defective
structure. The cleaned fittings shall be protected to machining, it may be discarded and another specimen
prevent recontamination. Protective coatings on socket substituted.
weld and butt welding fittings shall be suitable for
subsequent welding without removal of the coating.
When specified in the purchase order, parts may be 10. Rework and Retreatment
furnished in the as-formed or as-forged condition.
10.1 If the results of the mechanical tests do not
8.2 The forgings shall be free of injurious imperfec- conform to the requirements specified, the manufacturer
tions as defined below and shall have a workmanlike may reheat treat the forgings represented, and shall
finish. At the discretion of the inspector representing retest to the applicable requirements.
the purchaser, finished forgings shall be subject to
10.2 Individually tested forgings meeting all require-
rejection if surface imperfections acceptable under 8.2
ments shall be acceptable.
are not scattered but appear over a large area in excess
of what is considered a workmanlike finish. 10.3 Repair by Welding — Weld repairs shall be
permitted (see Supplementary Requirements S10) at
8.3 Depth of Injurious Imperfections — Selected
the discretion of the manufacturer with the following
typical linear surface imperfections shall be explored
limitations and requirements:
for depth. When the depth encroaches on the minimum
wall thickness of the finished forging, such imperfections 10.3.1 Repair by welding shall be made using
shall be considered injurious. welding procedures and welders qualified in accordance

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with ASME Section IX of the Code. The weld procedure 10.3.6 When the purchaser specifies Supplementary
qualification test shall also include impact tests of the Requirement S5, the same requirements shall apply to
weld metal and heat-affected zone. All impact test the weld procedure qualification tests.
specimens shall have the longitudinal axis transverse
10.3.7 Repair by welding shall not exceed 10%
to the weld and the base of the notch normal to the
of the surface area of the forging or 331⁄3% of the
weld surface. Weld specimens shall have the notch in
wall thickness of the finished forging, or 3⁄8 in. [9.5
weld metal and heat-affected zone specimens shall have
mm], whichever is less, without prior approval of the
the notch in the heat-affected zone. The specimens
purchaser.
shall be as large as permitted by the weldment thickness.
Where full-size specimens can be obtained and where 10.3.8 When approval of the purchaser is obtained,
there is sufficient weldment thickness, the weld speci- the limitations set forth in 10.3.7 may be exceeded,
men shall be taken with one side of the specimen but all other requirements of 10.3 shall apply.
within 1⁄16 in. [1.6 mm] of the weld surface. Heat-
affected zone impact test specimens shall be taken at
the same depth and locations applicable to the forging 11. Inspection
in 6.1.3.1 and 6.1.3.2. When forgings are thermally
11.1 The manufacturer shall afford the purchaser’s
treated after repair welding, the weld procedure test
inspector all reasonable facilities necessary to satisfy
plate shall be subjected to the same thermal treatment.
him that the material is being furnished in accordance
The mechanical properties of the weld procedure quali-
with the purchase order. Inspection by the purchaser
fication test shall conform to Section 6.
shall not interfere unnecessarily with the manufacturer’s
10.3.2 Defects shall be completely removed by operations. All tests and inspections shall be made at
chipping or grinding to sound metal as verified by the place of manufacture, unless otherwise agreed,
magnetic particle, or liquid penetrant inspection prior except for product analysis (see 5.2).
to welding.
10.3.3 For Grade LF1 forgings, and LF2 forgings
12. Rejection and Rehearing
that are to be only stress-relieved after repair welding,
the weld metal shall be deposited using carbon steel 12.1 Each forging that develops injurious defects
electrodes E7015, E7016, or E7018, complying with during shop working or application shall be rejected
AWS A5.1. For Grade LF2 forgings in all other condi- and the manufacturer notified.
tions of post-weld heat treatment, the weld metal shall
12.2 Samples representing material rejected by the
be deposited using low-alloy steel electrodes E7015-
purchaser shall be preserved until disposition of the
A1, E7016-A1, or E7018-A1, complying with AWS
claim has been agreed to between the manufacturer
5.5; for Grade LF3 forgings the weld metal shall be
and the purchaser.
deposited using low-alloy steel electrodes E8016-C2 or
E8018-C2, complying with AWS A5.5; for Grades LF5,
LF9, and LF787 forgings, the weld metal shall be
13. Certification
deposited using low-alloy steel electrodes E8016-C1 or
E8018-C1, complying with AWS A5.5. For Grade LF6, 13.1 For forgings made to specified dimensions when
the electrodes shall be low-hydrogen, E-XX15, E-XX16, agreed to by the purchaser, and for forgings made to
or E-XX18, complying with AWS A5.1 or A5.5, as dimensional standards, application of identification
applicable. marks as required in Section 14 shall be the certification
that the forgings have been furnished in accordance
10.3.4 After repair welding, the area welded shall
with the requirements of this specification.
be completely free of defects as verified by magnetic
particle or liquid penetrant inspection. 13.2 When test reports are required, they shall include
certification that all requirements of this specification
10.3.5 Forgings repair welded in the normalized,
have been met, and shall be traceable to the forging
normalized and tempered, or the quenched and tempered
represented. The specification designation included on
conditions shall be stress-relieved after repair welding
test reports shall include year of issue and revision
at 1100°F [590°C] minimum, but not higher than the
letter, if any. The manufacturer shall provide the follow-
temperature previously used for tempering the base
ing where applicable:
metal of the same forging, or shall be reheat treated
in accordance with 4.4. 13.2.1 Type heat treatment, Section 4,

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13.2.2 Chemical analysis results, Section 5 (Ta- the letters QT shall be stamped on the forgings following
ble 1), the ASTM designation.
13.2.3 Product analysis results, 5.2 (Tables 1 14.1.2 Forgings repaired by welding shall be
and 2), marked with the letter W following the ASTM desig-
nation.
13.2.4 Tensile property results, Section 6 (Table
3) report the yield strength and ultimate strength, in 14.2 If identification stamps are objectionable and
ksi [MPa], elongation and reduction in area, in percent, detrimental to the forging, and when so stated on the
purchase order, the marks may be painted or stenciled
13.2.5 Impact test results, 6.2 (Tables 4, 5, 6, on the forging, or stamped on a metal or plastic tag
and 7), which shall be securely attached to the forging.
13.2.6 Hardness results, 6.3.1, 14.3 When test reports are required, additional marks
13.2.7 Any supplementary testing required by the shall be used as necessary to identify the part with
purchase order, and the test report.

13.2.8 If repaired by welding, 14.1.2, letter W is 14.4 If the test temperature is other than the standard
to follow the ASTM designation. temperature specified in Table 5, the mark shall also
include the suffix letter S to the grade and class and
the test temperature. A prefix 0 to the test temperature
shall indicate a less than 0°F [−17.8°C] value. For
14. Product Marking example, LF2S 0175 denotes a test temperature of
−175°F [−115°C] for an LF2 part.
14.1 Identification marks consisting of the ASTM
specification number grade and class, manufacturer’s 14.5 Parts meeting all requirements for more than
name (Note 2) or symbol, the heat number or manufac- one class may be marked with more than one class
turer’s heat identification, size, and service rating, if such as LF2 CL1/CL2; LF5 CL1/CL2, and so forth.
applicable, shall be permanently placed on each forging 14.6 Bar Coding — In addition to the requirements
in a position that will not affect the usefulness of the in 14.1, 14.2, 14.3, 14.4, and 14.5, bar coding is
forging. The specification number marked on the forg- acceptable as a supplemental identification method. The
ings need not include specification year of issue and purchaser may specify in the order a specific bar coding
revision letter. The Standard Marking System of Valves, system to be used. The bar coding system, if applied
Fittings, Flanges, and Unions (SP25) of the Manufactur- at the discretion of the supplier, should be consistent
er’s Standardization Society of the Valve and Fittings with one of the published industry standards for bar
Industry may be followed except the word “steel” shall coding. If used on small parts, the bar code may be
not be substituted for the ASTM designation. applied to the box or a substantially applied tag.
NOTE 2 — For purposes of identification marking, the manufacturer
is considered the organization that certifies the piping component
was manufactured, sampled, and tested in accordance with this 15. Keywords
specification and the results have been determined to meet the
requirements of this specification. 15.1 carbon equivalent; pipe fittings, steel; piping
applications; pressure containing parts; steel flanges;
14.1.1 If the forgings have been quenched and steel forgings, alloy; steel forgings, carbon; steel valves;
tempered or quenched-and-precipitation heat treated, temperature service applications, low

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TABLE 1
CHEMICAL REQUIREMENTS †
Composition, wt. %

Grade
Element Grade LF1 Grade LF2 Grade LF3 Grade LF5 Grade LF6 LF9 Grade LF787
Carbon, max 0.30 0.30 0.20 0.30 0.22 0.20 0.07
Manganese 0.60–1.35 0.60–1.35 0.90 max 0.60–1.35 1.15–1.50 0.40–1.06 0.40–0.70
Phosphorus, max 0.035 0.035 0.035 0.035 0.025 0.035 0.025
Sulfur, max 0.040 0.040 0.040 0.040 0.025 0.040 0.025
Silicon A 0.15–0.30 0.15–0.30 0.20–0.35 0.20–0.35 0.15–0.30 ... 0.40 max
Nickel 0.40 max B 0.40 max B 3.3–3.7 1.0–2.0 0.40 max B 1.60–2.24 0.70–1.00
Chromium 0.30 max B,C 0.30 max B,C 0.30 max C 0.30 max C 0.30 max B,C 0.30 max C 0.60–0.90
Molybdenum 0.12 max B,C 0.12 max B,C 0.12 max C 0.12 max C 0.12 max B,C 0.12 max C 0.15–0.25
Copper 0.40 max B 0.40 max B 0.40 max C 0.40 max C 0.40 max B 0.75–1.25 1.00–1.30
Columbium 0.02 max 0.02 max 0.02 max 0.02 max 0.02 max 0.02 max 0.02 min
Vanadium 0.05 max 0.05 max 0.03 max 0.03 max 0.04–0.11 0.03 max 0.03 max
Nitrogen ... ... ... ... 0.01–0.030 ... ...
A
When vacuum carbon-deoxidation is required by Supplementary Requirement S11, the silicon content shall be 0.12% maximum.
B
The sum of copper, nickel, chromium, vanadium, and molybdenum shall not exceed 1.00% on heat analysis.
C
The sum of chromium and molybdenum shall not exceed 0.32% on heat analysis.
† Revisions to Table 1 approved April 10, 1996.

TABLE 2
PRODUCT ANALYSIS TOLERANCES
Permissible Variations Over Maximum Limit or Under Minimum Limit for Size Ranges Shown, %

To 100 in.2 Over 100 to 200 in.2 Over 200 to 400 in.2 Over 400 to 800 in.2
Limit or Maximum of [645 cm2] [645 to 1290 cm2] [1290 to 2580 cm2] [2580 to 5160 cm2]
Element Specified Range incl A incl A incl A incl A
Carbon to 0.30 incl 0.01 0.02 0.03 0.04
Manganese to 0.90 incl 0.03 0.04 0.05 0.06
over 0.90 to 1.35 incl 0.04 0.05 0.06 0.07
over 1.35 to 1.50 incl 0.10 0.10 0.10 0.10
Phosphorus over maximum only 0.005 0.010 0.010 0.010
Sulfur over maximum only 0.005 0.010 0.010 0.010
Silicon to 0.35 incl 0.02 0.02 0.03 0.04
Nickel up to and incl 1.00 0.03 0.03 0.03 0.03
over 1.00 to 2.00 incl 0.05 0.05 0.05 0.05
over 2.00 to 5.20 incl 0.07 0.07 0.07 0.07
Copper up to and incl 0.75 0.03 0.03 0.03 0.03
over 0.75 to 1.30 incl 0.05 0.05 0.05 0.05
Chromium to 0.90 incl 0.04 0.04 0.04 0.04
Molybdenum to 0.20 incl 0.01 0.01 0.01 0.01
over 0.20 to 0.40 incl 0.03 0.03 0.03 0.03
Columbium to 0.10 incl 0.01 0.01 0.01 0.01
Vanadium up to and incl 0.10 0.01 0.01 0.01 0.01
0.11 to 0.25 incl 0.02 0.02 0.02 0.02
Nitrogen up to and incl 0.02 0.005 0.005 0.005 0.005
over 0.02 to 0.19 incl 0.01 0.01 0.01 0.01
A
The significant cross section of the forging shall be governed by the main body diameter.

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TABLE 3
TENSILE PROPERTIES AT ROOM TEMPERATUREA
Grades

LF6 LF787
LF1 and LF2 LF3 and
LF5 Classes LF5 Classes
Class 1 1 and 2 Class 2 Class 1 2 and 3 LF9 Class 2 Class 3
Tensile strength, ksi [MPa] 60–85 70–95 70–95 66–91 75–100 63–88 65–85 75–95
[415–585] [485–655] [485–655] [455–630] [515–690] [435–605] [450–585] [515–655]
Yield strength, min, ksi [MPa] B,C 30 [205] 36 [250] 37.5 [260] 52 [360] 60 [415] 46 [315] 55 [380] 65 [450]
Elongation:
Standard round specimen, or small 25 22 22 22 20 25 20 20
proportional specimen, min % in
4D gage length
Strip specimen for wall thickness 5⁄16 28 30 30 30 28 28 28 28
in. (7.94 mm) and over and for
all small sizes tested in full sec-
tion; min % in 2 in. (50 mm)
Equation for calculating min elon- 48 t + 13 48 t + 15 48 t + 15 48 t + 15 48 t + 13 48 t + 13 48 t + 13 48 t + 13
gation for strip specimens thinner
than 5⁄16 in. (7.94 mm); min %
in 2 in. (50 mm)
t p actual thickness in inches
Reduction of area, min, % 38 30 35 40 40 38 45 45
A
See 6.3 for hardness tests.
B
Determined by either the 0.2% offset method or the 0.5% extension under load method.
C
For round specimens only.

TABLE 4
CHARPY V-NOTCH ENERGY REQUIREMENTS FOR STANDARD
SIZE [10 by 10 mm] SPECIMENS
Minimum Impact
Energy Required for Minimum Impact
Average of Each Set Energy Permitted for
of Three Specimens, One Specimen only of
Grade ft-lbf [J] a Set, ft-lbf [J]
LF1 and LF9 13 [18] 10 [14]
LF2, Class 1 15 [20] 12 [16]
LF3 15 [20] 12 [16]
LF5, Classes 1 and 2 15 [20] 12 [16]
LF787, Classes 2 and 3 15 [20] 12 [16]
LF6, Class 1 15 [20] 12 [16]
LF2, Class 2 20 [27] 15 [20]
LF3, Class 2 20 [27] 15 [20]
LF6, Classes 2 and 3 20 [27] 15 [20]

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TABLE 5
STANDARD IMPACT TEST TEMPERATURE FOR
STANDARD SIZE [10 by 10 mm] SPECIMENS
Grade Test Temperature, °F [°C]
LF1 −20 [−28.9]
LF2, Class 1 −50 [−45.6]
LF2, Class 2 0 [−18]
LF3 −150 [−101.1]
LF5, Classes 1 and 2 −75 [−59.4]
LF6, Classes 1 and 2 −60 [−50]
LF6, Class 3 0 [−18]
LF9 −100 [−73.3]
LF787, Class 2 −75 [−59.4]
LF787, Class 3 −100 [−73]

TABLE 6
MINIMUM EQUIVALENT ABSORBED ENERGY FT-LBF (J) FOR VARIOUS
SPECIMEN SIZES A
3 2 1 1 1
Standard ⁄4 Size ⁄3 Size ⁄2 Size ⁄3 Size ⁄4 Size
Size [10 by [10 by [10 by [10 by [10 by [10 by
10 mm] 7.5 mm] 6.6 mm] 5 mm] 3.3 mm] 2.5 mm]
15 [20] 12 [16] 10 [14] 8 [11] 5 [7] 4 [6]
13 [18] 10 [14] 9 [12] 7 [10] 5 [7] 4 [6]
12 [16] 10 [14] 9 [12] 7 [10] 4 [6] 3 [5]
10 [14] 8 [11] 7 [10] 5 [7] 3 [5] 3 [5]
A
Straight-line interpolation for intermediate values is permitted.

TABLE 7
CHARPY IMPACT TEST TEMPERATURE REDUCTION BELOW TABLE 5 TEST
TEMPERATURE WHEN THE SUBSIZE CHARPY IMPACT WIDTH ALONG NOTCH IS
LESS THAN 80% OF THE FORGING THICKNESS
Thickness of the Material
Represented (see 6.2.4.3),
or Charpy, Impact Temperature
Specimen Width Along the Reduction,
Size of Bar Notch A, in. [mm] °F [°C]
Standard 0.394 [10] 0 [0]
Standard 0.354 [9] 0 [0]
Standard 0.315 [8] 0 [0]
3
⁄4-size 0.295 [7.5] 5 [3]
3
⁄4-size 0.276 [7] 8 [5]
2
⁄3-size 0.262 [6.67] 10 [6]
2
⁄3-size 0.236 [6] 15 [8]
1
⁄2-size 0.197 [5] 20 [11]
1
⁄2-size 0.158 [4] 30 [17]
1
⁄3-size 0.131 [3.33] 35 [20]
1
⁄3-size 0.118 [3] 40 [22]
1
⁄4-size 0.099 [2.5] 50 [28]
A
Straight-line interpolation for intermediate values is permitted.

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 SA-350 /SA-350M 2001 SECTION II

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirements shall apply only when specified by the
purchaser in the inquiry, contract, or order.

S1. Macroetch Test S4.1.1 When higher test temperatures are em-
ployed, the actual test temperature may not be higher
S1.1 A sample forging shall be sectioned and etched
than that given in Table 8.
to show flow lines and internal soundness. The tests
shall be conducted according to Method E 381. S4.2 The test temperature shall be specified by
S1.2 Acceptance limits shall be as agreed upon the purchaser. When subsize specimens are used, the
between the manufacturer and the purchaser. manufacturer shall adjust test temperature in accordance
with the size restrictions of 6.2.4.2 and 6.2.4.3.

S4.3 The forging shall be marked with the specified

S2. Product Analysis test temperature in accordance with 14.4. A lower
temperature shall not be marked on the forging because
S2.1 A product analysis shall be made from each of the use of subsize specimens.
heat offered for delivery. The analysis shall conform
to the requirements specified in Table 1 with tolerances S4.4 The test results shall comply with Table 4 for
in Table 2. standard size specimens, and with Table 6 for subsize
specimens.
S2.2 If the results of any test fail to comply, two
additional forgings or representative test pieces from
the same heat shall be retested and the results shall
comply with the tables listed. If the results of either
one of these pieces fail to comply, each forging shall S5. Stress-Relieved Test Specimens
be checked or the heat rejected. All results shall be
S5.1 The test specimens shall be stress relieved.
reported to the purchaser and all forgings which do
Stress relieving shall be done after heat treatment in
not comply shall be rejected.
4.4 and before machining the specimens from the heat-
treated test material.

S5.2 The purchaser shall furnish the forging manufac-

S3. Additional Mechanical Tests
turer with details of the stress-relief treatment desired.
S3.1 In addition to the requirements of Section 6,
the heat identification shall be marked on each forging,
and one tension specimen and one test set of three
impact specimens shall be obtained from a representative
S6. Lateral Expansion
forging or test blank, the procedure for taking the test
material to be agreed upon between the manufacturer S6.1 Lateral expansion of the Charpy V-notch test
and purchaser. in accordance with Section 25 of Test Methods and
Definitions A 370 shall be measured and reported.
S3.2 The results of the test shall comply with 6.1.1
and 6.2.1, and shall be reported to the purchaser.

S7. Magnetic Particle Examination

S4. Other Impact Test Temperatures
S7.1 All surfaces of the finished forging shall be
S4.1 Impact test temperatures lower or higher than examined by a magnetic particle method. This method
the standard temperature in Table 5 of this specification shall be in accordance with Test Method A 275 /A
shall be used. 275M.

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S7.2 Acceptance limits shall be as agreed upon S12. Special Impact Test Requirements for
between the manufacturer and purchaser. Flanges (Note S1.1)
S12.1 Charpy test specimens shall be cut from an
actual flange representing each size, heat, and heat-
S8. Liquid Penetrant Examination treatment lot. If more than one size flange is represented
S8.1 All surfaces shall be examined by a liquid- by the same heat and heat-treatment lot, the maximum
penetrant method in accordance with Practice E 165. size flange shall be considered representative.

S8.2 Acceptance limits shall be as agreed upon S12.2 The number, location, and orientation of the
between the manufacturer and purchaser. test specimens shall be stated on the order.
S12.3 The test results shall comply with Table 4
for standard size specimens, and with Table 6 for
S9. Hydrostatic Testing subsize specimens.
S9.1 A hydrostatic test at a pressure agreed upon NOTE S1.1 — These special requirements should be considered for
between the manufacturer and purchaser shall be applied services when the applied stresses approach the maximum permissible
limits of the governing code, or the installation is subject to severe
by the manufacturer. cyclic conditions (7000 or more cycles over the expected life of the
installation), or both.

S10. Repair Welding

S13. Carbon Equivalent
S10.1 No repair welding shall be permitted without
prior approval of the purchaser. S13.1 The maximum carbon equivalent based on
heat analysis shall be as shown in Table 9.
S13.2 Determine the carbon equivalent (CE) as
S11. Vacuum Carbon-Deoxidized Steels follows:
S11.1 Material made to Grades LF1, LF2, LF3, LF5,
and LF9 shall be vacuum carbon-deoxidized, in which CE p C + Mn /6 + (Cr + Mo + V) /5 + (Ni + Cu) /15
case the silicon content shall be 0.12% maximum. The
test report shall indicate that the steel was vacuum S13.3 A lower maximum carbon equivalent may be
carbon-deoxidized. agreed upon between the supplier and the purchaser.

TABLE 8 TABLE 9
MAXIMUM SUPPLEMENTAL TEST MAXIMUM CARBON EQUIVALENT VALUE
TEMPERATURES Max. Thickness Less Max. Thickness
Grade Maximum Test Temperature, °F (°C) Grade Than or Equal to 2 in. Greater Than 2 in.

LF1 −10 [−23] LF1 0.45 0.46

LF2, Class 1 −35 [−37] LF2 0.47 0.48
LF3 −125 [−87] LF6 CL1 0.45 0.46
LF5, Classes 1 and 2 −60 [−51] LF6 CL2 0.47 0.48
LF6, Classes 1 and 2 −40 [−40]
LF9 −80 [−62]
LF787, Class 2 −60 [−51]
LF787, Class 3 −80 [−62]

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