Sinostar MACH is a professional ADI (Austempered Ductile Iron) manufacturer.

Today will learn the Chinese standard for ADI(Austempered Ductile Iron) in chronological order:

1.ADI China International Standard GB/T 24733-2009:

GB/T 24733-2009《Austempered Ductile Iron Castings》is our national standard.The Standard was issued on Nov 30, 2009 and took effect on Sept 1, 2010. General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. It is subject to the administration of the national standardization authority, the Standardization Administration of China. 

Modified GB/T 24733-2009 by revising and applying ISO 17804:2005 "Classification of Cast Austferrous Ductile Iron" and referring to relevant clauses from advanced foreign standards like ASTM A897/A897M-2006 "Standard Specification for Austempered Ductile Iron Parts", SAE J2477-2004 "Automobile Austempered Ductile Iron (ADI) Parts", AGMA939-A075/06 "Austempered Ductile Iron (ADI) for Gears". 

This standard defines the terms and definitions, grades, technical requirements, sampling and test blocks, test methods, acceptance rules and casting marks, packaging, storage and transportation rules for austempered ductile iron parts and applies to austempered ductile iron parts cast in a sand mold or mold with the thermal conductivity of a sand mold and submitted to austempered heat treatment. Austempered ductile iron parts that are cast using other castings process (such as metal mold, metal mold sand coating, shell mold, investment casting and continuous casting, etc.) can be used as references. 

Overview of standard content 

- Terms and definitions: Define terms like austempered ductile iron

- Grade: It defines the representation methods for austempered ductile iron part grades and the performance requirements of different grades.

- Technical requirements: Chemical composition, mechanical attributes, metallographic structure.

- Sampling and test blocks: About the requirements for sampling methods and the form & the size of the test blocks

- Test methods: Test methods such as tensile test, impact test, hardness test and so on.

- Inspection rules: defines the inspection categories, sampling plans, judgment methods, etc. of the inspected product;

- casting marking, packing and storage and transportation requirements: puts forward the requirement of marking on metal castings, packing method, storage and transportation

- Relationship with ISO 17804:2005: The revision uses ISO17804：2005,and adopts related clauses of foreign advanced standards such as ASTM A897/A897M-2006, SAE J2477-2004, AGMA939-A07 6/06 in the USA,and adds some clauses and appendices to enhance the applicability of the standard，such as adding casting appearance quality requirements and related testing methods.

2.ADI China International Standard GB/T 24733 - 2023:

GB/T 24733 - 2023 “Austempered Ductile Iron Castings” is a standard published and enforced by China on September 7th, 2023. It followed international standards when it formulated GB/T 24733-2023 by referring to corresponding domestic and foreign standards and advanced technologies like ISO I7804:2020, etc, making sure international integration. 

Brief description of the content of the standard

The content comprehensiveness of the entire content: GB/T 24733 - 2023 stipulates the terms and definitions,technical requirements,test methods,inspection rules and also the marking,packing,transportation,storages and quality certificates,all aspects of austempered ductile irong from the production stage till they are used. It can enable companies to have a standard to rely on during the production process, enabling people to know the relevant information to purchase and use the product and the assurance of quality.

Adaption improvement upon previous regulations: 

Based on GB/T 24733-2009, revised and improved to meet the development needs of an industry. As the austempered ductile iron castings industry develops forward，new technologies and market demands will come out. 

Such as a few of the relevant indicators in the Technical Requirement could be improved for the product with better quality and performance; update the Test Method to ensure the detection is more accurate and ensure that the product quality will meet higher standards; refine the Inspection Rules to strengthen the control of the Quality of the Product.

Can also make the improvement of the scientific nature and application of my country's standards for austempered ductile irons to improve the competition of my country's austempered ductile iron castings in the international market.