Russian scientists create smart steel
Researchers at South Ural State University are working on the production of an innovative, ultra-lightweight and ultra-strong steel called bainite. This new material has potential applications in the aviation, mechanical engineering and defense industries.
The authors of the development are Doctor of Physical and Mathematical Sciences, Professor Jalal Mirzaev and Associate Professor of the Department of Optoinformatics of the Institute of Natural Sciences and Mathematics of SUSU Ivan Buldashev.
High strength and malleable steel
Steel is an alloy of iron and carbon, but depending on the temperature to which the iron is heated, various steel structures can be produced. This is due to the fact that in the range from zero to 911 degrees Celsius, the properties of iron completely change.
At temperatures below 911 degrees Celsius, austenite enters a more malleable and softer phase called ferrite, which is formed upon slow cooling. In production, ferrite is used for mechanical processing. However, upon sharp cooling, austenite forms a superhard phase called martensite.
New steel for the oil industry
The basis of this study is bainite, which is similar to martensite. It is made by adding elements such as nickel, chromium, manganese and silicon. While maintaining the highest level of strength, bainite has a higher ductility than martensite. However, the malleability of bainite is not ultimately satisfactory. Researchers from SUSU are working on obtaining bainite that does not contain carbides, which will increase its impact resistance, since carbide particles are stress concentrators that stimulate fracture. Another important aspect is the reduction in the production time required for this type of steel.
It is important to note that this new steel will be 15-30 percent stronger. It can find applications in the defense industry and the oil industry. Pipes made from carbide-free bainite will not only have high impact resistance, but will also retain high strength in arctic climates. In the future, scientists will work to find the optimal composition of new steel, the properties of which will depend on the industry for which the material will be intended.
Additional information: I.L. Yakovleva et al. Structural aspect of isothermal bainitic transformation in high-carbon manganese-silicon steel, physics of metals and metallography (2018). DOI: 10.1134 /S0031918X18100149