Sinostar MACH's ADI Casting products all comply with international austenitic-bainitic ductile iron standards.

Now, we’ll study the international American ADI Austempered Ductile Iron standards in chronological order for today.

1. ASTM A644M—1992

ASTM A644M-1992 "terms for cast iron castings" produced by the American society for testing and materials (astm) is formulated specially for casting iron parts with definitions and explanations of terms for cast iron parts, providing a unified set of terminology for the processing, inspection and quality control of cast iron parts.

Overview of Standard Content:

Term Definition: The acicular ferrite + high-carbon austenite structure which is obtained after the austempering of ductile iron is called ausferrite formally.

Basic Function: It provides a terminology basis for the preparation of subsequent austempered ductile iron standardization work, unifies the names of specific organizations in the enterprise, and provides convenience for communication and research.

2.SAE J2477-2004

SAE J2477-2004 is a standard specification for the austempered ductile iron (ADI) parts for automobiles made by the Society of Automotive Engineers (SAE).

Overview of standard content:

Scope of application: This standard is special for automobiles and defines the technical requirements, test methods, inspection rules and so on for the automobile austempered ductile iron parts.

Technical requirements: Including the chemical composition and mechanical properties such as tensile strength, yield strength, elongation, hardness, etc., the metallographic structure, and the surface condition of the material.

Test methods: There are a great many testing methods provided for ADI performance, such as tensile tests, impact test, hardness tests, metallographic inspections.

Inspection rules: Clarified the inspection items, inspection methods and judgment criteria of the ADI materials to ensure that the materials comply with the standards.

3.ASTM A897/A897M -2006

The ASTM A897/A897M standard is published or revised in different years. of which the ASTM A897/ A897M - 2006 (2011) is relatively clear; this version, published by the American Society for Testing and Materials (US - ASTM) in 2006, was reissued in 2011. This standard belongs to the standard specification of austempered ductile iron castings, which is the j31 category in the Chinese classification.

Also, there are other versions of ASTM A897/A897M besides it, for example, ASTM A897/A897M-2015 that also have changed and revised the standards to comply with the latest development of industry and technology.

ASTM A897 / A897M standard specifies the technical requirements, test methods, inspection principles, marking, packaging and storage and transportation for the austempered ductile iron castings. This standard has an important role in the production process of austempered Ductile Iron Casting, the inspection and quality control of the final product and other related aspects. It also provides a unified set of standards and requirements for this industry.

Introduction to content of the standard:

Scope of the Specification is clear: The specification is clear in its scope, so it is clear what the scope of the standard is for producers and users. The production and sale of austempered ductile iron castings. The scope of applicability of the standard is clear. It can avoid arguments caused by different interpretations of the standard. such as the producer knows clearly what product he should produce and what kind of test should be done to match the standards, and at the consumer side, the consumer know clearly about whether he bought those good that match the standard.

performance range dynamic development The expansion of the performance range shows that austempering heat treatment technology is gradually expanding and being applied in the production process of ductile iron castings. With the development of science and technology, there are now new types of austenitic heat treatments appearing all the time, some with better performances than others. For example: it is possible to improve strength and toughness of the material by improving heat treatment parameters but we need not make the material more brittle. That is an increase in performance scope, which makes austempered ductile iron castings suitable for more places that require material such as aerospace, high-speed rail, etc. that have good properties.

Application guidance of performance relationship: 

Performance and relationship descriptions remind people to think about the things around them when imagining a product performing. There is no exact quantitative relationships between any one position of one casting with another position of same casting and casting with test sample but austempering heat treatment does always eliminate the differences in mechanical properties. In practice, people are unable to judge the performance of the entire casting based on the performance of the test piece alone, but must take into account factors such as the structure, dimensions and working condition of the casting. For example, the cooling rate of large castings is different, so the effect may also be different, it should be evaluated according to the actual situation when it is used.

Clarity of responsibility traceability:

To clarify what is produced and what is produced, so that when problems arise with the product, responsibilities can be traced back. Production of austempered ductile iron castings may involve many links, such as production of castings, machining of castings, and austempering heat treatment of castings. If they are made by different manufacturers, when there is a problem with the quality of the products, it will be easier to find out who's responsible for which issues, and then deal with them accordingly, thus improving the quality of the products and speeding up the production process by doing so.

Standardization of unit expression:

The provisions of unit expression can avoid misunderstandings and errors arising from unreasonable use of units. In different countries and regions in international exchanges and cooperation, they may adopt different unit systems. The standards stipulate that when values expressed in either SI units or inch-pound units are given, the value expressed in SI units is the standard to which the unit expressed in inch-pound units shall conform; each system shall be used separately. Put the values of each system together and it may no longer conform to the standard: It ensures the consistency and reliability of technical documents, test reports and the like, avoids production accidents or quality issues due to errors in unit conversion.

Adaptability of version updates: 

Different versions of updates can make the standard keep up with the latest industry technological and quality requirements in a timely manner. With the development of austempered ductile iron castings, we can see new types of materials, new processes, and new ways of testing. The standard modifies to suit these differences by amending reference standards, technical standards, and the like. and for example is there such a case in which because of non-detecting testing technology increases, the need for non-detecting testing maybe appears in the regulation to make product quality test more efficient.