ASTM A748/A748M-87(2003)

Standard Specification for Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls for Pressure Vessel Use

ABSTRACT
This specification covers statically cast dual metal rolls with the outer layer of the roll body being chilled white iron of different chemical composition than the core and journals of the roll which is gray cast iron. The castings are suitable for pressure containing parts such as pressure vessels, the design strength of which is based on the gray iron portion of the cylinder, and for service at the specified temperatures. The melting procedure shall be optional with the foundry and the casting process shall be controlled to produce a metallurgical bond between the chilled white iron exterior and gray iron interior. The chilled white iron exterior shall be made to the specified minimum hardness and the gray iron portion of the roll shall conform to the applicable class as determined by design requirements. The roll shall conform to the tensile strength requirement to be determined by tensile test and shall meet the required thickness. All surfaces shall be machined or ground, or both, prior to the rolls being placed into service.
SCOPE
1.1 This specification covers statically cast dual metal rolls with the outer layer of the roll body being chilled white iron of different chemical composition than the core and journals of the roll which is gray cast iron. The castings are suitable for pressure containing parts, the design strength of which is based on the gray iron portion of the cylinder. The castings are suitable for service at temperatures up to 450°F [232°C].
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 independent of the other. Combining values from the two systems may result in nonconformance with the specification.
1.3 The following safety hazards statement pertains only to the test method portion, 9, of this specification: 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-May-2003
• ICS: 77.140.80 - Iron and steel castings
• Technical Committee: A04 - Iron Castings
• Drafting Committee: A04.01 - Grey and White Iron Castings

Relations

• Replaces: ASTM A748/A748M-87(1998) - Standard Specification for Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls for Pressure Vessel Use
• Effective Date: 10-May-2003
• Replaced By: ASTM A748/A748M-87(2008) - Standard Specification for Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls for Pressure Vessel Use
• Effective Date: 01-Oct-2008

Standards Content (Sample)

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 748/A 748M – 87 (Reapproved 2003)
Standard Specification for
Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls
for Pressure Vessel Use
This standard is issued under the fixed designationA748/A748M; 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 3. Ordering Information
1.1 This specification covers statically cast dual metal rolls 3.1 Orders for material under this specification shall include
with the outer layer of the roll body being chilled white iron of the following information:
different chemical composition than the core and journals of 3.1.1 ASTM designation and year of issue,
the roll which is gray cast iron. The castings are suitable for 3.1.2 Dimensions of dual rolls,
pressure containing parts, the design strength of which is based 3.1.3 Class of gray iron in the roll core (see 4.2),
on the gray iron portion of the cylinder. The castings are 3.1.4 Inspection requirements, if different (see 10.1),
suitable for service at temperatures up to 450°F [232°C]. 3.1.5 Certification, if required (see 11.1), and
1.2 The values stated in either inch-pound units or SI units 3.1.6 Special position of marking information, if required
are to be regarded separately as standard. Within the text, the (see 12.1).
SI units are shown in brackets. The values stated in each 3.2 Any additional requirements not covered in this speci-
system are not exact equivalents; therefore, each system must fication are subject to agreement between the manufacturer and
be used independent of the other. Combining values from the purchaser.
two systems may result in nonconformance with the specifi-
4. Materials and Manufacture
cation.
1.3 The following safety hazards statement pertains only to 4.1 The melting procedure shall be optional with the
foundry.
the test method portion, 9, of this specification: This standard
does not purport to address all of the safety concerns, if any, 4.2 The chilled white iron exterior of the roll body shall be
made to a minimum hardness of 60 Scleroscope “C”. The gray
associatedwithitsuse.Itistheresponsibilityoftheuserofthis
iron portion of the roll shall conform to the applicable class of
standard to establish appropriate safety and health practices
and determine the applicability of regulatory limitations prior Specifications A 278 and A 278M, as determined by design
requirements.The scope of this specification shall include Nos.
to use.
20, 25, 30, and 35 of SpecificationA 278 [Nos. 150, 175, 200,
2. Referenced Documents
and 250 of Specification A 278M].
2.1 ASTM Standards: 4.3 The casting process shall be controlled to produce a
A 278 Specification for Gray Iron Castings for Pressure- metallurgical bond between the chilled white iron exterior and
Containing Parts for Temperatures Up to 650°F (350°C) gray iron interior of the roll body.
A 278M Specification for Gray Iron Castings for Pressure-
3 5. Test Requirements
Containing Parts for Temperatures Up to 345°C [Metric]
A 667/A667M Specification for Centrifugally Cast Dual 5.1 Tensile Requirements—Tensile bars removed from a
prolongation at one end of the roll journal, in accordance with
Metal (Gray and White Cast Iron) Cylinders
SpecificationsA 278 andA 278M, shall have a tensile strength
not less than 80 % of that specified by the applicable class of
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Specifications A 278 and A 278M.
CastingsandisthedirectresponsibilityofSubcommitteeA04.01onGreyandWhite
5.2 Thickness of Chilled White Iron:
Iron Castings.
Current edition approved May 10, 2003. Published May 2003. Originally
5.2.1 The thickness of the clear chilled white iron plus the
approved in 1977. Last previous edition approved in 1998 as A 748/A 748M – 87
mottled iron at the roll face shall not be more than 30 % of the
(1998).
2 total finished wall thickness.
Annual Book of ASTM Standards, Vol 01.02.
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