Plenary Lecture

Non-Stationary Nucleate Boiling as a Law of Nature and a Basis for Designing of IQ Technologies

Dr. Nikolai Kobasko
IQ Technologies Inc., Akron, USA
Intensive Technologies Ltd, Kiev, Ukraine
E-mails: nikobasko@yahoo.com

Abstract: The non – stationary nucleate boiling or self – regulated thermal process exists independently on will of people [1]. It can be observed during meteorites falling into rivers, lakes, seas and oceans. It is also observed on other planets where liquid is on their surface. The regularities of self-regulated thermal process are widely used in the practice when quenching of steel parts or cooling of forgings. In the plenary lecture the duration of non – stationary nucleate boiling will be discussed from the point of view of its practical use. It has been established that duration of non – stationary boiling is directly proportional to square of thickness of a body and inverse proportional to thermal diffusivity of a material, depends on configuration of a body, liquid properties and its velocity. The non – stationary nucleate boiling (self –regulated thermal process) is followed by amazing regularities:
-The surface temperature during nucleate boiling is maintained at the level of boiling (saturation) point.
-During this period an average effective heat transfer coefficients, generalized Biot numbers and Kondratjev numbers can be found. They significantly simplify cooling rate calculation of steel parts at their core. With size changing of a body and thermal properties of a material, the average generalized Biot number and Kondratjev number remain the same, i.e. have the same value.
-One can adjust surface temperature of steel part as prescribed by means of adjusting pressure even in condition when real Biot number Bi > . The last regularity allows governing the phase transformation during quenching.
Using established regularities, the new intensive quenching (IQ) technologies were developed: IQ-1; IQ-2: IQ-3. Additionally, during applying these new methods of quenching into the practice, very important two findings were discovered: the steel superstrengthening phenomenon [2, 3] and optimal quenched layer [4] which provides maximal residual compressive stresses at the surface of steel parts. Both factors increase service life of steel parts. Instead of oils plain water is used as a quenchant, no environmental problems appear here.

Brief Biography of the Speaker:
Dr. Nikolai Kobasko received his PhD from the National Academy of Sciences of Ukraine in 1969. He is a leading expert on quenching and heat transfer during the hardening of steels. He is the author and co-author of more than 250 scientific and technical papers, several books and brochures, and more than 30 patents and certificates. In 2004, Dr. Nikolai Kobasko received the Da Vinci Diamond Award and Certificate in recognition of an outstanding contribution to thermal science. Dr. Nikolai Kobasko is Co-Editor of the WSEAS TRANSACTIONS on HEAT and MASS TRANSFER and is a member of Editorial Board for International Journal of Mechanics (NAUN) and Journal of ASTM International (JAI). He was the Head of the laboratory of the Thermal Physics Institute of the National Academy of Sciences of Ukraine. He is co-founder of two consulting companies: IQ Technologies Inc. Akron, USA (1999) and Intensive Technologies Ltd, Kiev, Ukraine (2000). The aim of both companies is material savings, ecological problems solving and increaing service life of steel parts.
At present he is the Director of Technology and R&D of IQ Technologies Inc., Akron, USA and also President of the Intensive Technologies Ltd., Kiev, Ukraine. More information is provided in http://www.intensivequench.com and http://www.itl.kiev.ua .