ASTM A1095-15(2019)
(Specification)Standard Specification for High-Silicon Molybdenum Ferritic Iron Castings
Standard Specification for High-Silicon Molybdenum Ferritic Iron Castings
ABSTRACT
This specification covers general requirements and corresponding test methods for castings made of high-silicon molybdenum ferritic iron (SiMo). The requirements are prescribed for castings with microstructures of spheroidal graphite (SG) SiMo iron, compacted graphite (CG) SiMo iron, and mixed graphite or medium-nodularity graphite (MG) SiMo iron. MG iron microstructure is comprised of a mixture of spheroidal and compacted graphite shapes.
This specification covers: ordering information (including grade of silicon-molybdenum ferritic iron required, chemical composition requirements, microstructure and mechanical requirements, and special preparation for delivery); material, structural performance, and manufacturing practice; mechanical and chemical composition; workmanship, finish, and appearance; inspection and quality; certification; product marking; and packaging and package marking.
SCOPE
1.1 This specification covers castings made of high-silicon molybdenum ferritic iron, commonly known as SiMo. This specification includes castings with microstructures of spheroidal graphite (SG) SiMo iron, compacted graphite (CG) SiMo iron, and mixed graphite or medium-nodularity graphite (MG) SiMo iron. MG iron microstructure comprises a mixture of spheroidal and compacted graphite shapes. This standard specifies the condition, chemical composition, microstructure, and other technical requirements of three grades of ferritic cast irons, specified as SG SiMo, MG SiMo, and CG SiMo.
1.2 No precise quantitative relationship can be stated between the properties of iron in the various locations of the same casting or between the properties of castings and those of a test specimen cast from the same iron.
1.3 The values stated in SI units are to be regarded as standard. All chemical compositions are in mass percentage. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
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.
General Information
Relations
Buy Standard
Standards Content (Sample)
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.
Designation:A1095 −15 (Reapproved 2019)
Standard Specification for
High-Silicon Molybdenum Ferritic Iron Castings
This standard is issued under the fixed designation A1095; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope Graphite in Iron Castings
A395/A395M Specification for Ferritic Ductile Iron
1.1 This specification covers castings made of high-silicon
Pressure-Retaining Castings for Use at ElevatedTempera-
molybdenum ferritic iron, commonly known as SiMo. This
tures
specification includes castings with microstructures of spheroi-
A476/A476M Specification for Ductile Iron Castings for
dal graphite (SG) SiMo iron, compacted graphite (CG) SiMo
Paper Mill Dryer Rolls
iron, and mixed graphite or medium-nodularity graphite (MG)
A536 Specification for Ductile Iron Castings
SiMo iron. MG iron microstructure comprises a mixture of
A834 Specification for Common Requirements for Iron
spheroidal and compacted graphite shapes. This standard
Castings for General Industrial Use
specifies the condition, chemical composition, microstructure,
A842 Specification for Compacted Graphite Iron Castings
and other technical requirements of three grades of ferritic cast
A897/A897M Specification for Austempered Ductile Iron
irons, specified as SG SiMo, MG SiMo, and CG SiMo.
Castings
1.2 No precise quantitative relationship can be stated be-
D1976 Test Method for Elements in Water by Inductively-
tweenthepropertiesofironinthevariouslocationsofthesame
Coupled Plasma Atomic Emission Spectroscopy
casting or between the properties of castings and those of a test
D5381 Guide for X-Ray Fluorescence (XRF) Spectroscopy
specimen cast from the same iron.
of Pigments and Extenders
1.3 The values stated in SI units are to be regarded as E8/E8M Test Methods for Tension Testing of Metallic Ma-
terials
standard. All chemical compositions are in mass percentage.
No other units of measurement are included in this standard. E10 Test Method for Brinell Hardness of Metallic Materials
E21 TestMethodsforElevatedTemperatureTensionTestsof
1.4 This standard does not purport to address all of the
Metallic Materials
safety concerns, if any, associated with its use. It is the
E228 Test Method for Linear Thermal Expansion of Solid
responsibility of the user of this standard to establish appro-
Materials With a Push-Rod Dilatometer
priate safety, health, and environmental practices and deter-
E351 Test Methods for ChemicalAnalysis of Cast Iron—All
mine the applicability of regulatory limitations prior to use.
Types
1.5 This international standard was developed in accor-
E1184 Practice for Determination of Elements by Graphite
dance with internationally recognized principles on standard-
Furnace Atomic Absorption Spectrometry
ization established in the Decision on Principles for the
E1999 Test Method for Analysis of Cast Iron by Spark
Development of International Standards, Guides and Recom-
Atomic Emission Spectrometry
mendations issued by the World Trade Organization Technical
2.2 SAE (Society of Automotive Engineers) International
Barriers to Trade (TBT) Committee.
Standards:
2. Referenced Documents J434 Automotive Ductile (Nodular) Iron Castings
J1887 Automotive Compacted Graphite Iron Castings
2.1 ASTM Standards:
J2582 Automotive Ductile Iron Castings for High Tempera-
A247 Test Method for Evaluating the Microstructure of
ture Applications
2.3 Federal Standard:
FED-STD-123 Marking for Shipment (Civil Agencies)
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Castings and is the direct responsibility of Subcommittee A04.02 on Malleable and
2.4 American National Standard:
Ductile Iron Castings.
MIL-STD-129 Military Marking for Shipment and Storage
Current edition approved Nov. 1, 2019. Published November 2019. Originally
2.5 Other Publications:
approved in 2015. Last previous edition approved in 2015 as A1095 – 15. DOI:
10.1520/A1095-15R19.
AFS (American Foundry Society), Foundrymen’s Guide to
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Ductile Iron Microstructures, 1984
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
AFS, Iron Castings Engineering Handbook, 2004
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ASM Specialty Handbook, Cast Irons, 1999
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A1095−15 (2019)
ASM Specialty Handbook, Heat-Resistant Materials, 1999 5.3 Controlling the carbon equivalent is important to
ASM Handbook, Casting, Volume 15, 1998 achieve uniform graphite distribution and to minimize solidi-
ficationshrinkageandgraphiteflotation.Thecarbonequivalent
3. Ordering Information
control range shall be established by the manufacturer to
produce castings that meet the chemical composition ranges in
3.1 Orders for materials to this specification shall include
Table 1, the microstructure requirements in Section 6, and the
the following information:
mechanical properties in Table 2.
3.1.1 ASTM designation and year of issue,
3.1.2 Grade of silicon-molybdenum ferritic iron required,
5.4 Chromium can improve heat resistance of SiMo iron
3.1.3 Chemical composition requirements (see Section 5),
castings. Annealing heat treatments should be utilized if Cr
3.1.4 Microstructure and mechanical requirements (see Sec-
content exceeds 0.10 %.
tions 6 and 7),
5.5 The total concentrations of alloy elements including
3.1.5 Drawing and test coupon criteria (see Section 8),
Mo, Mn, Ni, Cu, W, V, Nb, and Cr shall not exceed 2.5 %.
3.1.6 Special requirements, if desired (see Sections9–11),
5.6 The lower limit of phosphorus for SG SiMo iron is
3.1.7 Certification, if so designated by purchaser (see Sec-
specified to eliminate the brittleness at medium temperature of
tion 12), and
approximately 425 °C.
3.1.8 Special preparation for delivery, if required (see Sec-
tion 14).
6. Microstructure
4. Materials and Manufacture
6.1 The matrix requirements for the three grades of SiMo
irons are the same: predominantly ferritic, a maximum 5 %
4.1 The manufacturer shall produce high-silicon molybde-
primary carbides, and adjacent to the cell boundaries, a
num iron castings with a microstructure consisting of a
maximum 30 % Mo-rich precipitates.
predominantly ferritic matrix in the as-cast condition. Small
amounts of flake graphite in the surface reaction zone are
6.2 All the three grades of SiMo iron castings for which
allowed only when agreed between the manufacturer and
chemical composition is specified in Table 1 shall be substan-
purchaser.
tially free of flake, exploded, chunky, crab, spiky, and floata-
tiongraphite.Flakegraphiteispermittedinthesurfacereaction
4.2 High-silicon ferritic SiMo iron castings are typically
zonetoamaximumdepthof0.30mmforsections≤10mmand
supplied in the as-cast condition. If heat treatment is agreed
to a maximum depth of 0.60 mm for sections >10 mm.
between the manufacturer and purchaser, castings can be either
fully or subcritically annealed. The recommended heat treat-
6.3 For SG SiMo iron, the graphite in the microstructure
ment practice is provided in Appendix X3.
shall consist of a minimum 80 % Type I and Type II graphite
according to Test Method A247.
5. Chemical Composition
6.4 For CG SiMo iron, the graphite in the microstructure
5.1 Chemical requirements for each grade are specified in
shall consist of a minimum 60 % Type IV graphite; the
Table 1. Chemical composition shall be determined from
remaining graphite shall be a combined maximum 40 % Type
chilled disk samples or samples representative of the castings
I, Type II, and Type III graphite according to Test Method
and in accordance with the applicable sections ofTest Methods
A247 and Specification A842.
D1976, E351, and E1999, Practice E1184, and Guide D5381.
6.5 For MG SiMo iron, the graphite in the microstructure
5.2 When agreed between the manufacturer and purchaser,
shallconsistofaminimum40%ofTypeIandTypeIIgraphite
chemistry control ranges may be tighter than those specified in
accordingtoTestMethodA247andarangeof30to60%Type
Table 1.
IV graphite according to Test Method A247 and Specification
A842.
TABLE 1 Chemical Composition Requirements
TABLE 2 Tensile and Hardness Requirements
Type
SG SiMo MG SiMo CG SiMo
Testing
Grade SG SiMo MG SiMo CG SiMo
Element Composition (mass %)
Temperature
Carbon 2.90–3.70 2.80–3.60 2.70–3.50 Tensile 500 450 400
Silicon 3.50–4.80 3.50–4.80 3.50–4.80
strength, min,
Molybdenum 0.40–1.50 0.40–1.50 0.40–1.50 MPa
Titanium 0.05 max 0.10 max 0.25 max
Magnesium 0.06 max 0.05 max 0.04 max Yield strength, 420 400 350
Manganese 0.50 max 0.50 max 0.50 max
min, MPa
Nickel 0.50 max 0.50 max 0.50 max
Room
Copper 0.30 max 0.30 max 0.30 max
Elongation in 6.0 4.0 1.5
temperature
Tungsten 0.30 max 0.30 max 0.30 max 25 mm or
Vanadium 0.10 max 0.10 max 0.10 max 50 mm, min,
Niobium 0.30 max 0.30 max 0.30 max %
Chromium 0.50 max 0.50 max 0.50 max
Phosphorus 0.02–0.05 0.05 max 0.05 max Brinell 190–270 190–270 190–270
Sulfur 0.02 max 0.02 max 0.02 max hardness,
Iron balance balance balance HBW
A1095−15 (2019)
6.6 The volume fraction of graphite is typically in the range 8.3 Separately cast test coupons shall be Y-blocks, keel
of 8 to 14 %. Graphite structure evaluations using image blocks, or modified keel blocks in accordance with Specifica-
analysis should only be done by agreement between the tions A395/A395M, A476/A476M, A536, A842, and A897/
manufacturer and purchaser. A897M.
8.3.1 The bottom Y-block thickness shall be 13 mm for
7. Mechanical Properties
casting thickness <13 mm, 25 mm for casting thickness 13 to
38 mm, and 75 mm for casting thickness >38 mm.
7.1 Tensile testing specimens shall be taken from separately
8.3.2 Leg thickness of keel blocks shall be 25 mm for
cast coupons unless otherwise agreed between the manufac-
casting thickness 13 to 38 mm. For other casting thickness, the
turer and purchaser. Brinell hardness testing specimens may be
keel block thickness shall be changed according to 8.3.1.
test coupons or castings, or both (see Section 8).
8.3.3 Modified keel blocks of 25 mm bar diameter can be
7.2 The iron as represented by the test specimens shall
substituted for the 25-mm Y-block or the 25-mm keel block.
conform to the requirements in Table 2 for tensile properties
8.3.4 The coupon molds shall have a thickness equal or
and hardness at room temperature. The tensile testing shall
greater than the coupon thickness. The coupons shall be left in
proceed in accordance with Test Methods E8/E8M for room
the mold until they have cooled to a black color (≤500 °C).
temperature andTest Methods E21 for elevated temperature. If
8.3.5 If the test bars show obvious defects, additional bars
the test results fail to conform to the requirements, two retests
shall be cut from other test blocks representing the same iron.
shall be performed with specimens removed from test coupons
8.4 When castings made in accordance with this specifica-
or castings produced using the same casting conditions. If
tion are produced by spheroidization directly in the mold, the
either retest fails to meet the specification requirements, the
manufacturermayuseeitherseparatelycasttestcouponsortest
castings represented by these test specimens shall be subject to
specimens cut from castings. When separately cast test cou-
rejection.
pons are used, selection shall be according to 8.1. If test bars
7.3 Yieldstrengthshallbedeterminedusingthe0.2 %offset
are to be cut from castings, test bar location shall be agreed
method in accordance with Test Methods E8/E8M. Brinell
between the manufacturer and purchaser and shall be indicated
hardness shall be determined in accordance with Test Method
on the casting drawing or model.
E10.
9. Additional Tests
7.4 The tensile properties at 425 °C are listed in Table 3 for
reference (nonmandatory) information to monitor the possible
9.1 In addition to the chemical, microstructure, and me-
brittleness at medium temperature. The medium temperature is
chanicalrequirementsinSections5–7,otherspecialtestssuch
defined in the range of 350 to 500 °C.
as nondestructive testing (radiographic soundness, liquid pen-
etrant examination, magnetic particle inspection, leakage test-
8. Test Coupons
ing) may be agreed between the manufacturer and purchaser.
8.1 Test coupons for microstructure determination and me-
Refer to Specification A834 for a list of common requirements
chanicalpropertiestestingmaybeseparatelycastorattachedto
for iron castings not specifically referenced elsewhere in this
castings. Separately cast test coupons shall be poured from the
specification.
same iron as the castings they represent. This means the same
10. Workmanship, Finish, and Appearance
chemical composition, the same inoculation practice, and an
equivalent cooling rate. The details of test coupons including
10.1 The castings shall be free of injurious defects. Surface
coupon type, size, location, sampling methods, and other of the castings shall be free of burnt-on sand and shall be
coupon-related control plans shall be agreed between the reasonably smooth. Runners, risers, and other cast-on pieces
manufacturer and purchaser. shall be removed. In other respects, the castings shall conform
to whatever points may be specifically agreed upon between
8.2 The type of metallographic specimen used shall be
the manufacturer and the purchaser.
agreedbetweenthemanufacturerandpurchaser.Threetypesof
metallographic specimens may be used: (1) separately cast 10.2 No repairing by plugging or welding of any kind shall
coupons, (2) a test lug cast with castings or attached to the be permitted unless written permission is granted by the
pouring basin or cup, and (3) specimens cut from castings. purchaser.
11. Inspection and Quality
TABLE 3 Tensile Properties at 425°C for References
11.1 At the time of an order, the purchaser should establish
Testing
Grade SG SiMo MG SiMo CG SiMo
an agreement for quality and inspection requirements with the
Temperature
Tensile 400 380 360
manufacturer.
strength, min,
11.2 Unless otherwise specified in contract or purchase
MPa
order, the manufacturer shall be responsible for carrying out all
Yield strength, 340 320 300
425 °C
the tests and inspections required by this specification. The
min, MPa
purchaser reserves the right to
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A1095 − 15 (Reapproved 2019)
Standard Specification for
High-Silicon Molybdenum Ferritic Iron Castings
This standard is issued under the fixed designation A1095; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope Graphite in Iron Castings
A395/A395M Specification for Ferritic Ductile Iron
1.1 This specification covers castings made of high-silicon
Pressure-Retaining Castings for Use at Elevated Tempera-
molybdenum ferritic iron, commonly known as SiMo. This
tures
specification includes castings with microstructures of spheroi-
A476/A476M Specification for Ductile Iron Castings for
dal graphite (SG) SiMo iron, compacted graphite (CG) SiMo
Paper Mill Dryer Rolls
iron, and mixed graphite or medium-nodularity graphite (MG)
A536 Specification for Ductile Iron Castings
SiMo iron. MG iron microstructure comprises a mixture of
A834 Specification for Common Requirements for Iron
spheroidal and compacted graphite shapes. This standard
Castings for General Industrial Use
specifies the condition, chemical composition, microstructure,
A842 Specification for Compacted Graphite Iron Castings
and other technical requirements of three grades of ferritic cast
A897/A897M Specification for Austempered Ductile Iron
irons, specified as SG SiMo, MG SiMo, and CG SiMo.
Castings
1.2 No precise quantitative relationship can be stated be-
D1976 Test Method for Elements in Water by Inductively-
tween the properties of iron in the various locations of the same
Coupled Plasma Atomic Emission Spectroscopy
casting or between the properties of castings and those of a test
D5381 Guide for X-Ray Fluorescence (XRF) Spectroscopy
specimen cast from the same iron.
of Pigments and Extenders
E8/E8M Test Methods for Tension Testing of Metallic Ma-
1.3 The values stated in SI units are to be regarded as
standard. All chemical compositions are in mass percentage. terials
E10 Test Method for Brinell Hardness of Metallic Materials
No other units of measurement are included in this standard.
E21 Test Methods for Elevated Temperature Tension Tests of
1.4 This standard does not purport to address all of the
Metallic Materials
safety concerns, if any, associated with its use. It is the
E228 Test Method for Linear Thermal Expansion of Solid
responsibility of the user of this standard to establish appro-
Materials With a Push-Rod Dilatometer
priate safety, health, and environmental practices and deter-
E351 Test Methods for Chemical Analysis of Cast Iron—All
mine the applicability of regulatory limitations prior to use.
Types
1.5 This international standard was developed in accor-
E1184 Practice for Determination of Elements by Graphite
dance with internationally recognized principles on standard-
Furnace Atomic Absorption Spectrometry
ization established in the Decision on Principles for the
E1999 Test Method for Analysis of Cast Iron by Spark
Development of International Standards, Guides and Recom-
Atomic Emission Spectrometry
mendations issued by the World Trade Organization Technical
2.2 SAE (Society of Automotive Engineers) International
Barriers to Trade (TBT) Committee.
Standards:
J434 Automotive Ductile (Nodular) Iron Castings
2. Referenced Documents
2 J1887 Automotive Compacted Graphite Iron Castings
2.1 ASTM Standards:
J2582 Automotive Ductile Iron Castings for High Tempera-
A247 Test Method for Evaluating the Microstructure of
ture Applications
2.3 Federal Standard:
FED-STD-123 Marking for Shipment (Civil Agencies)
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Castings and is the direct responsibility of Subcommittee A04.02 on Malleable and
2.4 American National Standard:
Ductile Iron Castings.
MIL-STD-129 Military Marking for Shipment and Storage
Current edition approved Nov. 1, 2019. Published November 2019. Originally
2.5 Other Publications:
approved in 2015. Last previous edition approved in 2015 as A1095 – 15. DOI:
10.1520/A1095-15R19.
AFS (American Foundry Society), Foundrymen’s Guide to
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Ductile Iron Microstructures, 1984
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
AFS, Iron Castings Engineering Handbook, 2004
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ASM Specialty Handbook, Cast Irons, 1999
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A1095 − 15 (2019)
ASM Specialty Handbook, Heat-Resistant Materials, 1999 5.3 Controlling the carbon equivalent is important to
ASM Handbook, Casting, Volume 15, 1998 achieve uniform graphite distribution and to minimize solidi-
fication shrinkage and graphite flotation. The carbon equivalent
3. Ordering Information
control range shall be established by the manufacturer to
produce castings that meet the chemical composition ranges in
3.1 Orders for materials to this specification shall include
Table 1, the microstructure requirements in Section 6, and the
the following information:
mechanical properties in Table 2.
3.1.1 ASTM designation and year of issue,
3.1.2 Grade of silicon-molybdenum ferritic iron required,
5.4 Chromium can improve heat resistance of SiMo iron
3.1.3 Chemical composition requirements (see Section 5),
castings. Annealing heat treatments should be utilized if Cr
3.1.4 Microstructure and mechanical requirements (see Sec-
content exceeds 0.10 %.
tions 6 and 7),
5.5 The total concentrations of alloy elements including
3.1.5 Drawing and test coupon criteria (see Section 8),
Mo, Mn, Ni, Cu, W, V, Nb, and Cr shall not exceed 2.5 %.
3.1.6 Special requirements, if desired (see Sections 9 – 11),
5.6 The lower limit of phosphorus for SG SiMo iron is
3.1.7 Certification, if so designated by purchaser (see Sec-
specified to eliminate the brittleness at medium temperature of
tion 12), and
approximately 425 °C.
3.1.8 Special preparation for delivery, if required (see Sec-
tion 14).
6. Microstructure
4. Materials and Manufacture
6.1 The matrix requirements for the three grades of SiMo
irons are the same: predominantly ferritic, a maximum 5 %
4.1 The manufacturer shall produce high-silicon molybde-
primary carbides, and adjacent to the cell boundaries, a
num iron castings with a microstructure consisting of a
maximum 30 % Mo-rich precipitates.
predominantly ferritic matrix in the as-cast condition. Small
amounts of flake graphite in the surface reaction zone are
6.2 All the three grades of SiMo iron castings for which
allowed only when agreed between the manufacturer and
chemical composition is specified in Table 1 shall be substan-
purchaser.
tially free of flake, exploded, chunky, crab, spiky, and floata-
tion graphite. Flake graphite is permitted in the surface reaction
4.2 High-silicon ferritic SiMo iron castings are typically
zone to a maximum depth of 0.30 mm for sections ≤10 mm and
supplied in the as-cast condition. If heat treatment is agreed
to a maximum depth of 0.60 mm for sections >10 mm.
between the manufacturer and purchaser, castings can be either
fully or subcritically annealed. The recommended heat treat-
6.3 For SG SiMo iron, the graphite in the microstructure
ment practice is provided in Appendix X3.
shall consist of a minimum 80 % Type I and Type II graphite
according to Test Method A247.
5. Chemical Composition
6.4 For CG SiMo iron, the graphite in the microstructure
5.1 Chemical requirements for each grade are specified in
shall consist of a minimum 60 % Type IV graphite; the
Table 1. Chemical composition shall be determined from
remaining graphite shall be a combined maximum 40 % Type
chilled disk samples or samples representative of the castings
I, Type II, and Type III graphite according to Test Method
and in accordance with the applicable sections of Test Methods
A247 and Specification A842.
D1976, E351, and E1999, Practice E1184, and Guide D5381.
6.5 For MG SiMo iron, the graphite in the microstructure
5.2 When agreed between the manufacturer and purchaser,
shall consist of a minimum 40 % of Type I and Type II graphite
chemistry control ranges may be tighter than those specified in
according to Test Method A247 and a range of 30 to 60 % Type
Table 1.
IV graphite according to Test Method A247 and Specification
A842.
TABLE 1 Chemical Composition Requirements
TABLE 2 Tensile and Hardness Requirements
Type
SG SiMo MG SiMo CG SiMo
Testing
Grade SG SiMo MG SiMo CG SiMo
Element Composition (mass %)
Temperature
Carbon 2.90–3.70 2.80–3.60 2.70–3.50
Tensile 500 450 400
Silicon 3.50–4.80 3.50–4.80 3.50–4.80 strength, min,
Molybdenum 0.40–1.50 0.40–1.50 0.40–1.50
MPa
Titanium 0.05 max 0.10 max 0.25 max
Magnesium 0.06 max 0.05 max 0.04 max
Yield strength, 420 400 350
Manganese 0.50 max 0.50 max 0.50 max min, MPa
Nickel 0.50 max 0.50 max 0.50 max
Room
Copper 0.30 max 0.30 max 0.30 max Elongation in 6.0 4.0 1.5
temperature
Tungsten 0.30 max 0.30 max 0.30 max 25 mm or
Vanadium 0.10 max 0.10 max 0.10 max 50 mm, min,
Niobium 0.30 max 0.30 max 0.30 max %
Chromium 0.50 max 0.50 max 0.50 max
Phosphorus 0.02–0.05 0.05 max 0.05 max Brinell 190–270 190–270 190–270
Sulfur 0.02 max 0.02 max 0.02 max hardness,
Iron balance balance balance HBW
A1095 − 15 (2019)
6.6 The volume fraction of graphite is typically in the range 8.3 Separately cast test coupons shall be Y-blocks, keel
of 8 to 14 %. Graphite structure evaluations using image blocks, or modified keel blocks in accordance with Specifica-
analysis should only be done by agreement between the tions A395/A395M, A476/A476M, A536, A842, and A897/
manufacturer and purchaser. A897M.
8.3.1 The bottom Y-block thickness shall be 13 mm for
7. Mechanical Properties
casting thickness <13 mm, 25 mm for casting thickness 13 to
38 mm, and 75 mm for casting thickness >38 mm.
7.1 Tensile testing specimens shall be taken from separately
8.3.2 Leg thickness of keel blocks shall be 25 mm for
cast coupons unless otherwise agreed between the manufac-
casting thickness 13 to 38 mm. For other casting thickness, the
turer and purchaser. Brinell hardness testing specimens may be
keel block thickness shall be changed according to 8.3.1.
test coupons or castings, or both (see Section 8).
8.3.3 Modified keel blocks of 25 mm bar diameter can be
7.2 The iron as represented by the test specimens shall
substituted for the 25-mm Y-block or the 25-mm keel block.
conform to the requirements in Table 2 for tensile properties
8.3.4 The coupon molds shall have a thickness equal or
and hardness at room temperature. The tensile testing shall
greater than the coupon thickness. The coupons shall be left in
proceed in accordance with Test Methods E8/E8M for room
the mold until they have cooled to a black color (≤500 °C).
temperature and Test Methods E21 for elevated temperature. If
8.3.5 If the test bars show obvious defects, additional bars
the test results fail to conform to the requirements, two retests
shall be cut from other test blocks representing the same iron.
shall be performed with specimens removed from test coupons
8.4 When castings made in accordance with this specifica-
or castings produced using the same casting conditions. If
tion are produced by spheroidization directly in the mold, the
either retest fails to meet the specification requirements, the
manufacturer may use either separately cast test coupons or test
castings represented by these test specimens shall be subject to
specimens cut from castings. When separately cast test cou-
rejection.
pons are used, selection shall be according to 8.1. If test bars
7.3 Yield strength shall be determined using the 0.2 % offset
are to be cut from castings, test bar location shall be agreed
method in accordance with Test Methods E8/E8M. Brinell
between the manufacturer and purchaser and shall be indicated
hardness shall be determined in accordance with Test Method
on the casting drawing or model.
E10.
9. Additional Tests
7.4 The tensile properties at 425 °C are listed in Table 3 for
reference (nonmandatory) information to monitor the possible
9.1 In addition to the chemical, microstructure, and me-
brittleness at medium temperature. The medium temperature is
chanical requirements in Sections 5 – 7, other special tests such
defined in the range of 350 to 500 °C.
as nondestructive testing (radiographic soundness, liquid pen-
etrant examination, magnetic particle inspection, leakage test-
8. Test Coupons
ing) may be agreed between the manufacturer and purchaser.
8.1 Test coupons for microstructure determination and me-
Refer to Specification A834 for a list of common requirements
chanical properties testing may be separately cast or attached to
for iron castings not specifically referenced elsewhere in this
castings. Separately cast test coupons shall be poured from the
specification.
same iron as the castings they represent. This means the same
10. Workmanship, Finish, and Appearance
chemical composition, the same inoculation practice, and an
equivalent cooling rate. The details of test coupons including 10.1 The castings shall be free of injurious defects. Surface
coupon type, size, location, sampling methods, and other of the castings shall be free of burnt-on sand and shall be
coupon-related control plans shall be agreed between the reasonably smooth. Runners, risers, and other cast-on pieces
manufacturer and purchaser. shall be removed. In other respects, the castings shall conform
to whatever points may be specifically agreed upon between
8.2 The type of metallographic specimen used shall be
the manufacturer and the purchaser.
agreed between the manufacturer and purchaser. Three types of
metallographic specimens may be used: (1) separately cast 10.2 No repairing by plugging or welding of any kind shall
coupons, (2) a test lug cast with castings or attached to the be permitted unless written permission is granted by the
pouring basin or cup, and (3) specimens cut from castings.
purchaser.
11. Inspection and Quality
TABLE 3 Tensile Properties at 425 °C for References
11.1 At the time of an order, the purchaser should establish
Testing
Grade SG SiMo MG SiMo CG SiMo
an agreement for quality and inspection requirements with the
Temperature
Tensile 400 380 360
manufacturer.
strength, min,
MPa 11.2 Unless otherwise specified in contract or purchase
order, the manufacturer shall be responsible for carrying out all
Yield strength, 340 320 300
425 °C
the tests and inspections required by this specification. The
min, MPa
purchaser reserves th
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A1095 − 15 A1095 − 15 (Reapproved 2019)
Standard Specification for
High-Silicon Molybdenum Ferritic Iron Castings
This standard is issued under the fixed designation A1095; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers castings made of high-silicon molybdenum ferritic iron, commonly known as SiMo. This
specification includes castings with microstructures of spheroidal graphite (SG) SiMo iron, compacted graphite (CG) SiMo iron,
and mixed graphite or medium-nodularity graphite (MG) SiMo iron. MG iron microstructure comprises a mixture of spheroidal
and compacted graphite shapes. This standard specifies the condition, chemical composition, microstructure, and other technical
requirements of three grades of ferritic cast irons, specified as SG SiMo, MG SiMo, and CG SiMo.
1.2 No precise quantitative relationship can be stated between the properties of iron in the various locations of the same casting
or between the properties of castings and those of a test specimen cast from the same iron.
1.3 The values stated in SI units are to be regarded as standard. All chemical compositions are in mass percentage. No other
units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
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 ASTM Standards:
A247 Test Method for Evaluating the Microstructure of Graphite in Iron Castings
A395A395/A395M Specification for Ferritic Ductile Iron Pressure-Retaining Castings for Use at Elevated Temperatures
A476/A476M Specification for Ductile Iron Castings for Paper Mill Dryer Rolls
A536 Specification for Ductile Iron Castings
A834 Specification for Common Requirements for Iron Castings for General Industrial Use
A842 Specification for Compacted Graphite Iron Castings
A897/A897M Specification for Austempered Ductile Iron Castings
D1976 Test Method for Elements in Water by Inductively-Coupled Plasma Atomic Emission Spectroscopy
D5381 Guide for X-Ray Fluorescence (XRF) Spectroscopy of Pigments and Extenders
E8/E8M Test Methods for Tension Testing of Metallic Materials
E10 Test Method for Brinell Hardness of Metallic Materials
E21 Test Methods for Elevated Temperature Tension Tests of Metallic Materials
E228 Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
E351 Test Methods for Chemical Analysis of Cast Iron—All Types
E1184 Practice for Determination of Elements by Graphite Furnace Atomic Absorption Spectrometry
E1999 Test Method for Analysis of Cast Iron by Spark Atomic Emission Spectrometry
2.2 SAE (Society of Automotive Engineers) International Standards:
J434 Automotive Ductile (Nodular) Iron Castings
J1887 Automotive Compacted Graphite Iron Castings
This test method specification is under the jurisdiction of ASTM Committee A04 on Iron Castings and is the direct responsibility of Subcommittee A04.02 on Malleable
and Ductile Iron Castings.
Current edition approved Nov. 1, 2015Nov. 1, 2019. Published December 2015November 2019. Originally approved in 2015. Last previous edition approved in 2015 as
A1095 – 15. DOI: 10.1520/A1095-1510.1520/A1095-15R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A1095 − 15 (2019)
J2582 Automotive Ductile Iron Castings for High Temperature Applications
2.3 Federal Standard:
FED-STD-123 Marking for Shipment (Civil Agencies)
2.4 American National Standard:
MIL-STD-129 Military Marking for Shipment and Storage
2.5 Other Publications:
AFS (American Foundry Society), Foundrymen’s Guide to Ductile Iron Microstructures, 1984
AFS, Iron Castings Engineering Handbook, 2004
ASM Specialty Handbook, Cast Irons, 1999
ASM Specialty Handbook, Heat-Resistant Materials, 1999
ASM Handbook, Casting, Volume 15, 1998
3. Ordering Information
3.1 Orders for materials to this specification shall include the following information:
3.1.1 ASTM designation and year of issue,
3.1.2 Grade of silicon-molybdenum ferritic iron required,
3.1.3 Chemical composition requirements (see Section 5),
3.1.4 Microstructure and mechanical requirements (see Sections 6 and 76 and 7),
3.1.5 Drawing and test coupon criteria (see Section 8),
3.1.6 Special requirements, if desired (see Sections 9 and– 11),
3.1.7 Certification, if so designated by purchaser (see Section 12), and
3.1.8 Special preparation for delivery, if required (see Section 14).
4. Materials and Manufacture
4.1 The manufacturer shall produce high-silicon molybdenum iron castings with a microstructure consisting of a predominantly
ferritic matrix in the as-cast condition. Small amounts of flake graphite in the surface reaction zone are allowed only when agreed
between the manufacturer and purchaser.
4.2 High-silicon ferritic SiMo iron castings are typically supplied in the as-cast condition. If heat treatment is agreed between
the manufacturer and purchaser, castings can be either fully or subcritically annealed. The recommended heat treatment practice
is provided in Appendix X3.
5. Chemical Composition
5.1 Chemical requirements for each grade are specified in Table 1. Chemical composition shall be determined from chilled disk
samples or samples representative of the castings and in accordance with the applicable sections of Test Methods D1976, E351,
and E1999, Practice E1184, and Guide D5381.
5.2 When agreed between the manufacturer and purchaser, chemistry control ranges may be tighter than those specified in Table
1.
5.3 Controlling the carbon equivalent is important to achieve uniform graphite distribution and to minimize solidification
shrinkage and graphite flotation. The carbon equivalent control range shall be established by the manufacturer to produce castings
that meet the chemical composition ranges in Table 1, the microstructure requirements in Section 6, and the mechanical properties
in Table 2.
TABLE 1 Chemical Composition Requirements
Type
SG SiMo MG SiMo CG SiMo
Element Composition (mass %)
Carbon 2.90–3.70 2.80–3.60 2.70–3.50
Silicon 3.50–4.80 3.50–4.80 3.50–4.80
Molybdenum 0.40–1.50 0.40–1.50 0.40–1.50
Titanium 0.05 max 0.10 max 0.25 max
Magnesium 0.06 max 0.05 max 0.04 max
Manganese 0.50 max 0.50 max 0.50 max
Nickel 0.50 max 0.50 max 0.50 max
Copper 0.30 max 0.30 max 0.30 max
Tungsten 0.30 max 0.30 max 0.30 max
Vanadium 0.10 max 0.10 max 0.10 max
Niobium 0.30 max 0.30 max 0.30 max
Chromium 0.50 max 0.50 max 0.50 max
Phosphorus 0.02–0.05 0.05 max 0.05 max
Sulfur 0.02 max 0.02 max 0.02 max
Iron balance balance balance
A1095 − 15 (2019)
TABLE 2 Tensile and Hardness Requirements
Testing
Grade SG SiMo MG SiMo CG SiMo
Temperature
Tensile 500 450 400
strength, min,
MPa
Yield 420 400 350
strength, min,
MPa
Room
Room Elongation in 6.0 4.0 1.5
temperature
temperture 25 mm or
50 mm, min,
%
Elongation in 6.0 4.0 1.5
25 mm or
50 mm, min,
%
Brinell 190–270 190–270 190–270
hardness,
HBW
5.4 Chromium can improve heat resistance of SiMo iron castings. Annealing heat treatments should be utilized if Cr content
exceeds 0.10 %.
5.5 The total concentrations of alloy elements including Mo, Mn, Ni, Cu, W, V, Nb, and Cr shall not exceed 2.5 %.
5.6 The lower limit of phosphorus for SG SiMo iron is specified to eliminate the brittleness at medium temperature of
approximately 425°C.425 °C.
6. Microstructure
6.1 The matrix requirements for the three grades of SiMo irons are the same: predominantly ferritic, a maximum 5 % primary
carbides, and adjacent to the cell boundaries, a maximum 30 % Mo-rich precipitates.
6.2 All the three grades of SiMo iron castings for which chemical composition is specified in Table 1 shall be substantially free
of flake, exploded, chunky, crab, spiky, and floatation graphite. Flake graphite is permitted in the surface reaction zone to a
maximum depth of 0.30 mm for sections ≤10 mm and to a maximum depth of 0.60 mm for sections >10 mm.
6.3 For SG SiMo iron, the graphite in the microstructure shall consist of a minimum 80 % Type I and Type II graphite according
to Test Method A247.
6.4 For CG SiMo iron, the graphite in the microstructure shall consist of a minimum 60 % Type IV graphite; the remaining
graphite shall be a combined maximum 40 % Type I, Type II, and Type III graphite according to Test Method A247 and
Specification A842.
6.5 For MG SiMo iron, the graphite in the microstructure shall consist of a minimum 40 % of Type I and Type II graphite
according to Test Method A247 and a range of 30 to 60 % Type IV graphite according to Test Method A247 and Specification
A842.
6.6 The volume fraction of graphite is typically in the range of 8 to 14 %. Graphite structure evaluations using image analysis
should only be done by agreement between the manufacturer and purchaser.
7. Mechanical Properties
7.1 Tensile testing specimens shall be taken from separately cast coupons unless otherwise agreed between the manufacturer
and purchaser. Brinell hardness testing specimens may be test coupons or castings, or both (see Section 8).
7.2 The iron as represented by the test specimens shall conform to the requirements in Table 2 for tensile properties and hardness
at room temperature. The tensile testing shall proceed in accordance with Test Methods E8/E8M for room temperature and Test
MethodMethods E21 for elevated temperature. If the test results fail to conform to the requirements, two retests shall be performed
with specimens removed from test coupons or castings produced using the same casting conditions. If either retest fails to meet
the specification requirements, the castings represented by these test specimens shall be subject to rejection.
7.3 Yield strength shall be determined using the 0.2 % offset method in accordance with Test Methods E8/E8M. Brinell hardness
shall be determined in accordance with Test Method E10.
7.4 The tensile properties at 425°C425 °C are listed in Table 3 for reference (nonmandatory) information to monitor the possible
brittleness at medium temperature. The medium temperature is defined in the range of 350 to 500°C.500 °C.
A1095 − 15 (2019)
TABLE 3 Tensile Properties at 425°C425 °C for References
Testing
Grade SG SiMo MG SiMo CG SiMo
Temperature
Tensile 400 380 360
strength, min,
MPa
425 °C 425°C Yield strength, 340 320 300
min, MPa
Yield strength, 340 320 300
min, MPa
Elongation in 5.0 4.0 1.5
25 mm or 50
mm, min, %
8. Test Coupons
8.1 Test coupons for microstructure determination and mechanical properties testing may be separately cast or attached to
castings. Separately cast test coupons shall be poured from the same iron as the castings they represent. This means the same
chemical composition, the same inoculation practice, and an equivalent cooling rate. The details of test coupons including coupon
type, size, location, sampling methods, and other coupon-related control plans shall be agreed between the manufacturer and
purchaser.
8.2 The type of metallographic specimen used shall be agreed between the manufacturer and purchaser. Three types of
metallographic specimens may be used: (1)(1) separately cast coupons, (2)(2) a test lug cast with castings or attached to the pouring
basin or cup, and (3)(3) specimens cut from castings.
8.3 Separately cast test coupons shall be Y-blocks, keel blocks, or modified keel blocks in accordance with Specifications
A395A395/A395M, A476/A476M, A536, A842, and A897/A897M.
8.3.1 The bottom Y-block thickness shall be 13 mm for casting thickness <13 mm, 25 mm for casting thickness 13 to 38 mm,
and 75 mm for casting thickness >38 mm.
8.3.2 Leg thickness of keel blocks shall be 25 mm for casting thickness 13 to 38 mm. For other casting thickness, the keel block
thickness shall be changed according to 8.3.1.
8.3.3 Modified keel blocks of 25 mm bar diameter can be substituted for the 25-mm Y-block or the 25-mm keel block.
8.3.4 The coupon molds shall have a thickness equal or greater than the coupon thickness. The coupons shall be left in the mold
until they have cooled to a black color (≤500°C).(≤500 °C).
8.3.5 If the test bars show obvious defects, additional bars shall be cut from other test blocks representing the same iron.
8.4 When castings made in accordance with this specification are produced by spheroidization directly in the mold, the
manufacturer may use either separately cast test coupons or test specimens cut from castings. When separately cast test coupons
are used, selection shall be according to 8.1. If test bars are to be cut from castings, test bar location shall be agreed between the
manufacturer and purchaser and shall be indicated on the casting drawing or model.
9. Additional Tests
9.1 In addition to the chemical, microstructure, and mechanical requirements in Sections 5 – 7, other special tests such as
nondestructive testing (radiographic soundness, liquid penetrant examination, magnetic particle inspection, leakage testing) may
be agreed between the manufacturer and purchaser. Refer to Specification A834 for a list of common requirements for iron castings
not specifically referenced elsewhere in this specification.
10. Workmanship, Finish, and Appearance
10.1 The castings shall be free of injurious defects. Surface of the castings shall be free of burnt-on sand and shall be reasonably
smooth. Runners, risers, and other cast-on pieces shall be removed. In other respects, the castings shall conform to whatever points
may be
...
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