ASTM A897/A897M-22 PDF
Standard Specification for Austempered Ductile Iron Castings
Standard Specification for Austempered Ductile Iron Castings
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 11
- Дата публикации:
- 1 октября 2022 г.
- Издание:
- A897/A897M
- ICS:
- 77.140.80
ABSTRACT This specification covers ductile iron castings that are subsequently heat treated by an austempering process. The chemical composition requirements may be agreed upon between the manufacturer, heat treater, and the purchaser. Requirements for the microstructure constituents such as graphite, ausferrite (acicular ferrite and high carbon, stable austenite), pearlite, and martensite are prescribed. The iron shall conform to the mechanical property requirements including tensile strength, yield strength, elongation, impact energy, and Brinell hardness. Castings shall be heat treated by an austempering process detailed in this specification. The standard specimens for tension and Charpy impact tests are illustrated. SCOPE 1.1 This specification covers ductile iron castings that are subsequently heat treated by an austempering process as defined in 9.1. 1.2 The application of the austempering heat treatment extends the range of properties achievable in ductile iron castings. 1.3 No precise quantitative relationship can be stated between the properties of the iron in various locations of the same casting or between the properties of castings and those of a test specimen cast from the same iron (see Appendix X1). However, austempering heat treatment will tend to diminish any differences in mechanical properties. 1.4 The production of castings, machining (if required), and the austempering heat treatments may be performed by different manufacturers, as covered in Section 13. The purchaser should establish by contract agreement, at the time of ordering, the responsibility of the various parties for meeting the specification requirements. 1.5 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. 1.5.1 Exception—Within the text, the SI units are shown in brackets. 1.6 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.
Abstract
Overview
ASTM A897/A897M-22 – Standard Specification for Austempered Ductile Iron Castings defines the requirements for ductile iron castings that are enhanced by austempering-a specialized heat treatment. This standard specifies mechanical and microstructural properties, testing requirements, and quality protocols for producing high-strength, versatile iron castings used in a range of applications. Mechanical properties such as tensile strength, yield strength, elongation, impact energy, and Brinell hardness are addressed, along with the processes for agreeing upon and verifying test methods and quality responsibilities. ASTM A897/A897M-22 supports the production of components that demand superior performance, ductility, and durability.
Key Topics
- Austempering Process: The specification centers on ductile iron castings that undergo austempering, an isothermal heat treatment process that imparts a predominantly ausferritic microstructure, improving mechanical properties.
- Grades and Properties: It defines several grades of austempered ductile iron (ADI), with mechanical property levels (tensile/yield strength, elongation) specified in both SI and inch-pound units.
- Grades are assigned based on combinations of strength and ductility, with provisions for both standard and mixed microstructures.
- Microstructure Requirements: The majority of the matrix must be ausferrite for standard grades, while mixed microstructure grades contain both proeutectoid ferrite and ausferrite.
- Testing and Quality Assurance:
- Specifies methods for tension and impact testing, including suitable test coupon configurations.
- Defines Brinell hardness testing areas and methodologies.
- Establishes protocols for ordering, inspection, certification, and clear allocation of quality responsibility among manufacturers and heat treaters.
- Dimensional and Surface Quality:
- Demands castings to be free from defects like cracks, porosity, and non-metallic inclusions.
- Disallows welding repairs.
- Outlines requirements for appearance, dimensions, and surface finish.
Applications
Austempered ductile iron castings manufactured to ASTM A897/A897M-22 find critical use in industries where high strength, wear resistance, and good ductility are important. Typical applications include:
- Automotive: Gears, crankshafts, suspension components, and safety-critical parts.
- Agricultural and Construction Equipment: Wear-resistant implements, brackets, and housings.
- Industrial Machinery: Components such as sprockets, rollers, machine bases, and housings that require a combination of toughness and strength.
- Railroad and Heavy Equipment: Structural and moving parts that benefit from the superior impact resistance of ADI.
- Defense and Shipbuilding: Where high reliability and consistent performance in harsh environments are needed.
By complying with ASTM A897/A897M-22, manufacturers and purchasers ensure reliable, predictable material performance and meet the rigorous demands of modern engineering.
Related Standards
For comprehensive quality and compatibility, ASTM A897/A897M-22 references several related standards and test methods, including:
- ASTM A247: Method for evaluating graphite microstructure in iron castings.
- ASTM E8/E8M: Test methods for tension testing of metallic materials.
- ASTM E10: Brinell hardness testing method for metallic materials.
- ASTM E23: Notched bar impact testing for metallic materials.
- ASTM A834: Specification for common requirements for iron castings in industrial use.
- ASTM A370: Mechanical testing methods for steel products.
Meeting the requirements of ASTM A897/A897M-22 along with these referenced standards ensures that austempered ductile iron castings achieve the desired balance of strength, ductility, reliability, and quality control.
Keywords: ASTM A897, austempered ductile iron, ADI, heat treatment, ductile iron castings, ausferrite, mechanical properties, industrial castings, Brinell hardness, microstructure, material specification, quality assurance, tensile strength, yield strength, impact energy
Технические детали
- Технический комитет
- A04 - Iron Castings
- SKU
- ASTM A897/A897M-22
Похожие стандарты
Другие стандарты ASTM
ASTM-TPT-47
Phase I & Phase II Environmental Site Assessment Processes
Phase I & Phase II Environmental Site Assessment Processes
ASTM-TPT-8
Phase I Environmental Site Assessment Practices For Commercial Real Estate: Phase I Site Assessment & Transac…
ASTM-TPT-1137
ASTM D975 Standard Specification for Diesel Fuel
ASTM D975 Standard Specification for Diesel Fuel
ASTM-TPT-1202
ASTM D8421 Standard Test Method for Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Ma…
ASTM D8421 Standard Test Method -- eLearning Course
ASTM-TPT-691
Microaprendizagem para D4057: Amostragem de ponto (PT)
D4057 Microlearning: Spot Sampling Portuguese
ASTM-TPT-1091
Metodo de prueba estandar D4052 de ASTM -- Curso de aprendizaje electrónico (ES)
Modulo eLearning para ASTM D4052 en espanol
ASTM ACEM20180086
Using Neutron Radiography to Quantify the Settlement of Fresh Concrete
Specifications have been implemented for concrete bridge decks in North America that restrict the use of higher slump concrete mixtures primarily because of concerns about differential settlement and…
ASTM ACEM20180041
Experimental Study of Competing Failure of Reinforced Concrete Based on the Weibull Distribution
To predict the failure lifetime of reinforced concrete, a current accelerating corrosion test was performed on concrete by simulating the environment in an area with saline soil. To study the concret…