It has been more than 60 years since the discovery of high-strength ductile iron. Because of its good comprehensive performance, convenient manufacturing and low cost, it can not only replace gray cast iron to improve the quality of cast iron materials, but also replace cast steel, forged steel and welded parts to reduce production costs. According to U.S. statistics, 40% of the total output of high-strength ductile iron is to replace forged steel parts, stamping parts and weldments, 25% is to replace malleable cast iron parts, 20% is to replace gray iron parts, 15% is to replace cast steel parts. Internationally, the proportion of high-strength ductile iron to the total number of castings and the proportion of high-strength ductile iron/cast steel are regarded as important indicators to measure the level of industrialization of a country.

The reason why industrial developed countries can guarantee the quality of high-strength ductile iron is that the raw and auxiliary materials produced by high-strength ductile iron are of good quality and stability, the process equipment is advanced, and the testing technology is perfect. Therefore, it has been used for automobiles, rail transportation equipment, wind power, nuclear power and other important parts to replace forged steel and cast steel parts. From 1964 to 1965, General Motors used high-strength ductile iron to replace the steering knuckle assembled from 13 forgings and stamping parts. It was a breakthrough in the application of high-strength ductile iron parts in automobile chassis safety parts. Since then, high-strength ductile iron has achieved faster development. In recent years, China's high-strength ductile iron has developed rapidly, and the output of high-strength ductile iron has been in the forefront of the world for 12 consecutive years. However, the proportion of high-strength ductile iron production in the total output of castings and cast steel is still lower than the world average, and the application of important parts is not extensive enough, indicating that China's high-strength ductile iron still has a lot of room for development.

Due to the presence of graphite, ductile iron has good shock absorption, which can reduce the working noise of parts. For example, the noise comparison test of ADI and 40Cr timing gears manufactured by K series hobbing on AK machine shows that the noise of ADI gears is 1.92dB lower than that of 40Cr gears, and the noise on the gear side is 5.3dB lower. The noise of ADI gears processed by AKI series grinding is 2.5dB lower than that of 38CrMnAl and 40Cr nitrided steel gears processed by hobbing. Because graphite itself has self-lubricating ability, it can improve the wear resistance of parts.

For more than 60 years since the birth of ductile iron, domestic and foreign experts have basically completed the basic theoretical and technical work on its chemical composition, microstructure transformation, mechanical properties and performance, and the scope of application has also been determined. Some foundry enterprises and national high-strength ductile iron standards have also been published, implemented and revised many times. All these indicate that the high-strength ductile iron technology has entered the stage of industrial production from experimental research, development and application.

Stability and consistency are still noteworthy problems in the production of ductile iron in China. To improve the threshold of high-strength ductile iron and austempering high-strength ductile iron production enterprises, only qualified enterprises with excellent process equipment, advanced production technology and testing equipment, and strict and scientific management are qualified to produce important and critical high-strength ductile iron castings. In addition, the replacement of important parts should not be blindly promoted and expanded, and the design should be improved by finite element method according to the specific force of the parts and the performance characteristics of high-strength ductile iron and ADI, in order to achieve the desired effect.