ASTM A748/A748M-87(2022)
(Specification)Standard Specification for Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls for Pressure Vessel Use
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 SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.
1.3 The following safety hazards statement pertains only to the test method portion, Section 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 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
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: A748/A748M −87 (Reapproved 2022)
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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope A667/A667M Specification for Centrifugally Cast Dual
Metal (Gray and White Cast Iron) Cylinders
1.1 This specification covers statically cast dual metal rolls
with the outer layer of the roll body being chilled white iron of
3. Ordering Information
different chemical composition than the core and journals of
the roll which is gray cast iron. The castings are suitable for
3.1 Orders for material under this specification shall include
pressure-containing parts, the design strength of which is based
the following information:
on the gray iron portion of the cylinder. The castings are
3.1.1 ASTM designation and year of issue,
suitable for service at temperatures up to 450 °F [232 °C].
3.1.2 Dimensions of dual rolls,
3.1.3 Class of gray iron in the roll core (see 4.2),
1.2 The values stated in either SI units or inch-pound units
3.1.4 Inspection requirements, if different (see 10.1),
are to be regarded separately as standard. The values stated in
3.1.5 Certification, if required (see 11.1), and
each system may not be exact equivalents; therefore, each
3.1.6 Special position of marking information, if required
system shall be used independently of the other. Combining
(see 12.1).
values from the two systems may result in nonconformance
with the standard.
3.2 Any additional requirements not covered in this speci-
fication are subject to agreement between the manufacturer and
1.3 The following safety hazards statement pertains only to
the test method portion, Section 9, of this specification: This purchaser.
standarddoesnotpurporttoaddressallofthesafetyconcerns,
ifany,associatedwithitsuse.Itistheresponsibilityoftheuser 4. Materials and Manufacture
of this standard to establish appropriate safety, health, and
4.1 The melting procedure shall be optional with the
environmental practices and determine the applicability of
foundry.
regulatory limitations prior to use.
4.2 The chilled white iron exterior of the roll body shall be
1.4 This international standard was developed in accor-
made to a minimum hardness of 60 Scleroscope “C.” The gray
dance with internationally recognized principles on standard-
iron portion of the roll shall conform to the applicable class of
ization established in the Decision on Principles for the
Specification A278/A278M, as determined by design require-
Development of International Standards, Guides and Recom-
ments.ThescopeofthisspecificationshallincludeNos.20,25,
mendations issued by the World Trade Organization Technical
30, 35, 150, 175, 200, and 250 of Specification A278/A278M.
Barriers to Trade (TBT) Committee.
4.3 The casting process shall be controlled to produce a
2. Referenced Documents
metallurgical bond between the chilled white iron exterior and
2.1 ASTM Standards:
gray iron interior of the roll body.
A278/A278M Specification for Gray Iron Castings for
Pressure-Containing Parts for Temperatures Up to 650 °F
5. Test Requirements
(350 °C)
5.1 Tensile Requirements—Tensile bars removed from a
prolongation at one end of the roll journal, in accordance with
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Specification A278/A278M, shall have a tensile strength not
CastingsandisthedirectresponsibilityofSubcommitteeA04.01onGreyandWhite
Iron Castings.
less than 80 % of that specified by the applicable class of
Current edition approved Oct. 1, 2022. Published October 2022. Originally
Specification A278/A278M.
approved in 1977. Last previous edition approved in 2018 as A748/A748M – 87
(2018). DOI: 10.1520/A0748_A0748M-87R22.
5.2 Thickness of Chilled White Iron:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.2.1 The thickness of the clear chilled white iron plus the
contact ASTM Customer Service at service@
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.