ASTM A995/A995M-98(2003)

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Designation: A 995/A 995M – 98 (Reapproved 2003)
Standard Specification for
Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for
Pressure-Containing Parts
This standard is issued under the fixed designationA 995/A 995M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
TABLE 1 Heat Treatment Requirements
1. Scope
Grade Heat Treatment
1.1 This specification covers austenitic-ferritic (duplex)
1B Heat to 1900°F [1040°C] minimum, hold for sufficient time to heat
stainless steel castings for valves, flanges, fittings, and other
casting uniformly to temperature, quench in water or rapid cool by
pressure-containing parts.
other means.
1.2 The duplex stainless steels offer a combination of
2A Heat to 2050°F [1120°C] minimum, hold for sufficient time to heat
casting uniformly to temperature, quench in water or rapid cool by
enhanced mechanical properties and corrosion resistance when
other means.
properly balanced in composition and properly heat treated.
3A Heat to 1950°F [1070°C] minimum, hold for sufficient time to heat
Ferrite levels are not specified, but these grades will develop a
casting uniformly to temperature, quench in water or rapid cool by
other means.
range of approximately 30 to 60 % ferrite with the balance
4A Heat to 2050°F [1120°C] minimum for sufficient time to heat casting
austenite. It is the responsibility of the purchaser to determine
uniformly to temperature and water quench, or the casting may be
which grade shall be furnished depending on design and furnace cooled to 1850°F [1010°C] minimum, hold for 15 min
minimum and then water quench. A rapid cool by other means may
service conditions, mechanical properties, and corrosion-
be employed in lieu of water quench.
resistant characteristics.
5A Heat to 2050°F [1120°C] minimum, hold for sufficient time to heat
casting to temperature, furnace cool to 1910°F [1045°C] minimum,
NOTE 1—Because of the possibility of precipitation of embrittling
quench in water or rapid cool by other means.
phases, the grades included in this specification are not recommended for
6A Heat to 2010°F [1100°C] minimum, hold for sufficient time to heat
service at temperatures above 600°F [315°C].
casting uniformly to temperature, quench in water or cool rapidly by
other means.
1.3 The values stated in either inch-pound units or SI units
are to be regarded separately as standard. Within the text, the
SI units are shown in brackets. The values stated in each
Systematic Manual Point Count
system are not exact equivalents; therefore, each system must
be used independently of the other. Combining values from the
3. Terminology
two systems may result in nonconformance with the specifi-
3.1 Definitions of Terms Specific to This Standard:
cation.
3.1.1 duplex stainless steel—an iron-chromium-nickel-
2. Referenced Documents
molybdenum alloy which when properly heat treated consists
of approximately 30 to 60 % ferrite with the balance austenite.
2.1 ASTM Standards:
A 488/A 488M PracticeforSteelCastings,Welding,Quali-
4. General Conditions for Delivery
fication of Procedures and Personnel
4.1 Material furnished to this specification shall conform to
A 703/A 703M Specification for Steel Castings, General
the applicable requirements of Specification A 703/A 703M,
Requirements, for Pressure-Containing Parts
including the supplementary requirements that are indicated on
E 125 Reference Photographs for Magnetic Particle Indica-
the purchaser order. Failure to comply with the general
tions on Ferrous Castings
requirements of Specification A 703/A 703M constitutes non-
E 165 Test Method for Liquid Penetrant Examination
conformance with this specification. In case of conflict be-
E 562 Test Method for Determining Volume Fraction by
tween the requirements of the specification and Specification
A 703/A 703M, this specification shall prevail.
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
5. Ordering Information
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
5.1 It is the responsibility of the purchaser to specify all
A01.18 on Castings.
Current edition approved April 10, 2003. Published April 2003. Originally requirements that are necessary for material ordered under this
approved in 1998. Last previous edition approved in 1998 as A 995 – 98.
Annual Book of ASTM Standards, Vol 01.02.
Annual Book of ASTM Standards, Vol 03.03.
Annual Book of ASTM Standards, Vol 03.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 995/A 995M – 98 (2003)
TABLE 2 Chemical Requirements
A A
Grade 1B 2A 3A 4A 5A 6A
Type 25Cr-5Ni-M0-Cu-N 24Cr-10Ni-Mo-N 25Cr-5Ni-Mo-N 22Cr-5Ni-Mo-N 25Cr-7Ni-Mo-N 25Cr-7Ni-Mo-N
UNS J93372 J93345 J93371 J92205 J93404 J93380
ACI CD4MCuN CE8MN CD6MN CD3MN CE3MN CD3MWCuN
Composition:
Carbon, max 0.040 0.080 0.060 0.030 0.030 0.030
Manganese, max 1.00 1.00 1.00 1.50 1.50 1.00
Silicon, max 1.00 1.50 1.00 1.00 1.00 1.00
Phosphorus, max 0.040 0.040 0.040 0.040 0.040 0.030
Sulfur, max 0.040 0.040 0.040 0.020 0.040 0.025
Chromium 24.5-26.5 22.5-25.5 24.0-27.0 21.0-23.5 24.0-26.0 24.0-26.0
Nickel 4.7-6.0 8.0-11.0 4.0-6.0 4.5-6.5 6.0-8.0 6.5-8.5
Molybdenum 1.70-2.30 3.0-4.5 1.75-2.50 2.5-3.5 4.0-5.0 3.0-4.0
Copper 2.7-3.3 . . . . . . 1.00, max . . . 0.50-1.00
Tungsten . . . . . . . . . . . . . . . 0.50-1.00
Nitrogen 0.10-0.25 0.10-0.30 0.15-0.25 0.10-0.30 0.10-0.30 0.20-0.30
A
%Cr+3.3% Mo+16% N$ 40.
TABLE 3 Tensile Requirements
Grade 1B 2A 3A 4A 5A 6A
Type 25Cr-5Ni-Mo-Cu-N 24Cr-10Ni-Mo-N 25Cr-5Ni-Mo-N 22Cr-5Ni-Mo-N 25Cr-7Ni-Mo-N 25Cr-7Ni-Mo-N
Tensile strength, ksi [MPa], min 100 [690] 95 [655] 95 [655] 90 [620] 100 [690] 100 [690]
Yield strength
...