The Treatments And Process Of Ductile Iron

Castings of ductile iron have machining and production cost advantages over steel fabrications, castings and forgings within the limitations of ductility and impact properties and have strength to weight advantage over the Grey iron castings where the cracking is a problem. While the ductile iron's production is more involved than Grey iron, it is still possible to produce difficult shapes which can be easily machined then steel. In the cast conditions, a range of properties from high ductility to comparatively to high strength can be produced by the control of production and composition process.

Austempered Ductile Iron provides a range of high strength iron with toughness and higher ductility. These irons have the advantage that the base iron is machinable. The potential of ADI applications is vast, as it's properties coupled with the flexibility and cost benefits of ductile iron. The range of properties may be extended by subsequent heat treatment and alloy adjustments including surface hardening and thorough hardening by tempering and quenching. The discrete form of graphite in comparison to the planes of weakness of graphite flakes in Grey iron means that the properties of ductile iron are determined more by the matrix of material than the form of graphite.

Austempered Ductile Iron is a wear resistance material, high strength produced by heat treating a high quality ductile iron. The required wear resistance and strength characteristics are achieved by a combination of micro structure achieved by the subsequent control of a three stage heat treatment process. The wide range of properties means that different grades of ductile iron can be used in different applications.

Transformations Of Ferrous Alloys And Other Metals

Heat treatment is all about the subsequent cooling and heating of the metals in a controlled manner in to alter the mechanical and the physical properties of metals without changing the shape of that specific product. At times, this process of heat treatment can be done in an periodic fashion. The reason for this is the process of manufacturing that works towards the cooling or heating the metal, like welding or forming.

Austempering Technology is an isothermal transformation of a ferrous alloy at a temperature above that of martensite formation and below that of pear-lite formation. Austempering of steel offers many promising benefits:

1. Increased toughness, strength and ductility, at a given hardness.

2. Reduced distortion, which lessens the subsequent stock removal, machining time, inspection, scrap and sorting.

3.The shortest time cycle to through-harden within the hardness range of thirty five to fifty five HRC, with resulting savings in capital investment and energy.

Austempering is also an isothermal transformation used to form a stable high-carbon austenite in harden-able cast irons and unique acicular matrix of bainitic ferrite. Austempering technology exactly means an uniform structure. It is a heat treatment that applied to the ferrous materials and then produces a structure that is stronger and tougher than comparable structures produced with the ordinary heat treatments. This typical heat treaters heat the parts to Red Heat in a controlled atmosphere and then quench them in a bath of oil or water that is maybe even as high as a few hundred degree Fahrenheit or near room temperature. This technology truly is - a better mousetrap.