What should you know about ductile iron?
Just as parents rejoice in the achievements of their children, the “Nicmas” concern is proud of the production of high-quality, high-strength cast iron.
Why should special attention be paid to the production process of high-strength cast iron with spheroidal graphite when analyzing the activities of the “Nicmas” concern? And all because its value lies in high mechanical properties.
These strong features are determined by the structure of the metal base, as well as the shape and dimensions of the graphite. The spherical form of graphite inclusions is the most compact, it has the smallest ratio of the surface of the inclusions to their volume, as a result of which the working section of the casting is weakened to a lesser extent, and the stress concentration on the graphite inclusions is practically absent. With this form of graphite inclusions, both the strength and plastic properties of cast iron increase dramatically. As a result, cast iron with spheroidal graphite as a structural material is extremely valuable for its wear resistance, plasticity and viscosity.
A significant achievement in the development of casting is the development of a method of obtaining high-strength cast iron with spheroidal graphite. This material has a good combination of high physico-mechanical and technological properties. As a result of numerous studies and extensive production experience, it has been established that high-strength cast iron (HC) can be successfully used instead of gray and malleable cast iron, carbon and alloy steel in many cases.
What result do we get at the output?
Based on many years of experience and conducted experiments, we can safely say that the required level of mechanical properties of high-strength HC60 cast iron (hardness, strength, wear resistance, etc.) is achieved by heating the cast iron above the critical temperatures of the formation of the austenite structure, by saturating it with carbon.
As a result of heat treatment of the cast structure by quenching and subsequent high-temperature annealing, supercooled austenite is completely or partially transformed into bainite, which provides the necessary hardness and plasticity of cast iron.
Replacing ordinary gray cast iron with high-strength cast iron allows you to significantly reduce the weight of castings by reducing the thickness of their cross-sections, while maintaining and even increasing operational reliability.
How is the production process of high-strength ductile iron?
It is worth starting with the fact that when obtaining the primary cast structure, it is impossible to obtain all the necessary characteristics of the material. That is why heat treatment processes for changing the microstructure of cast iron were developed and then researched.
The most expedient from a technical and economic point of view is the use of high-strength cast iron instead of steel for thin-walled cast parts of complex configuration. Compared to steel, this cast iron has 1.5-2.0 times more liquid, is not prone to the formation of hot cracks, and ensures the production of dense metal in small cross-sections without the use of “spills”. At the same time, the cost of casting from high-strength cast iron is 25-30% lower than the cost of steel casting.
The use of high-strength cast iron in many cases makes it possible to significantly reduce the weight of parts and increase the rate of metal utilization. However, it should be noted that, despite the mentioned advantages of high-strength cast iron in comparison with other foundry alloys, its scope of application and scale of production are very limited until recently, but the production of the Foundry Section of the “Nicmas” concern is constantly working on improving casting. Castings such as crankshafts used in compressors are produced at the Foundry production facility from HC60 alloy.
And with such high-quality material, we are never embarrassed in front of our customers.