ASTM A942-95
(Specification)Standard Specification for Centrifugally Cast White Iron/Gray Iron Dual Metal Abrasion- Resistant Roll Shells
Standard Specification for Centrifugally Cast White Iron/Gray Iron Dual Metal Abrasion- Resistant Roll Shells
SCOPE
1.1 This specification covers double pour, centrifugally cast, abrasion-resistant roll shells for general application. The outer layer is white iron and the inner layer is gray iron. There shall be no gradient of mottled iron between the white iron and the gray iron.
1.2 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 system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.
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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: A 942 – 95
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Centrifugally Cast White Iron/Gray Iron Dual Metal Abrasion-
1
Resistant Roll Shells
This standard is issued under the fixed designation A 942; 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.
1. Scope 4.1.7 Certification, if required (Section 13), and
4.1.8 Special position of marking information, if required
1.1 This specification covers double pour, centrifugally cast,
(Section 14).
abrasion-resistant roll shells for general application. The outer
4.2 Additional requirements may be agreed upon between
layer is white iron and the inner layer is gray iron. There shall
the manufacturer and the purchaser.
be no gradient of mottled iron between the white iron and the
gray iron.
5. Materials and Manufacture
1.2 The values stated in either inch-pound units or SI units
5.1 Both the white and the gray irons may be melted by any
are to be regarded separately as standard. Within the text, the
suitable melting process.
SI units are shown in brackets. The values stated in each
5.2 The white iron portion of the casting shall be produced
system are not exact equivalents; therefore, each system must
by chemistry rather than chilling.
be used independently of the other. Combining values from the
two systems may result in nonconformance with this specifi-
6. Chemical Composition
cation.
6.1 A chemical analysis shall be performed by the manu-
2. Referenced Documents facturer on both the white and gray irons. The chemical
compositions shall be controlled to obtain the required me-
2.1 ASTM Standards:
2 chanical properties.
A 48 Specification for Gray Iron Castings
3
E 8 Test Methods for Tension Testing of Metallic Materials
7. Mechanical Properties
E 10 Test Method for Brinell Hardness of Metallic Materi-
3 7.1 The white iron shall conform to the following require-
als
ments:
3. Classification
Type I — 450 to 500 HB
Type II — 500 to 550 HB
3.1 The white iron portion of the casting shall be classified
Type III — 550 to 600 HB
by type based upon Brinell Hardness. Type IV — 600 to 650 HB
3.2 The gray iron portion of the casting shall be classified by
7.2 The gray iron shall conform to the following require-
class based upon tensile strength.
ments:
Tensile Strength
4. Ordering Information
Class min, ksi min, (MPa)
4.1 Orders for material to this specification shall include the No. 20 20 (138)
No. 25 25 (172)
following:
No. 30 30 (207)
4.1.1 Specification title, designation, and year of issue,
No. 35 35 (241)
4.1.2 Quantity of castings required,
8. Other Requirements
4.1.3 Required dimensions and thickness of white iron layer
(8.1),
8.1 The thickness of the white iron layer shall be a mini-
1
4.1.4 Surface condition—as cast or machined, mum of ⁄2 in.
4.1.5 Type of white iron required for the outer layer of the
8.1.1 The thickness of the white iron layer shall be mea-
casting (7.1), sured on the roll face at each end and shall conform to the
4.1.6 Class of gray iron required for the inner layer (7.2),
specified thickness.
9. Finish and Appearance
1
This specification is under the jurisdiction of ASTM Committee A-4 on Iron
9.1 All exterior surfaces shall be machined or ground prior
Castings and is the direct responsibility of Subcommittee A04.01 on Grey and White
Iron Castings. to the rolls being placed into service.
Current edition approved Oct. 10, 1995. Published December 1995.
9.2 The manufacturer shall be responsible for providing
2
Annual Book of ASTM Standards, Vol 01.02.
castings with adequate stock for final machining.
3
Annual Book of ASTM Standards, Vol 03.01.
1
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A 942
9.3 Surfaces and corners of the machined castings shall be whose services have been contracted by the manufacturer.
free from burrs and extremely sharp edges. Complete records of all tests and inspections shall be main-
9.4 Machined surfaces of the castings may be protected by tained by the manufacturer, and shall be available for review by
the application of a rust and corrosion preventive coating. the purchaser.
10. Sampling
13. Certification
10.1 Each casting shall be tested for chemical composition,
13.1 When specified by the purchaser, the manufacturer’s
hardness, and tensile strength.
certification shall be furnished to the purchaser stating that the
10.2 The white iron hardness shall be determined on crop
material was manufactured, sampled, tested, and inspected in
ends removed from the castin
...
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