Phenomena of Physics Taking Place During Hardening of Steel Parts in Liquid Media That Can Be Investigated by Liščić/Petrofer Probe

Abstract

Abstract This article discusses some phenomena of physics taking place during the quenching of steel parts in liquid media, such as the formation of a double surface electrical layer, poker effect, the existence of the second spike of the cooling rate during the quenching of the standard probe in salt water and alkali water solutions, and the self-regulation of the part surface temperature during the transient nucleate boiling process. A double electrical layer is conceived around the steel part surface during quenching in salt water or alkali water solutions. This layer prevents the film boiling during quenching because of electrical forces arising in it. This is a reason for maximizing critical heat flux densities. When immersing the quench probe into a salt (alkali) water solution, the probe surface temperature drops almost instantly (within 1–2 s) to the liquid boiling point and remains at this level for a relatively long time. A so-called self-regulated thermal process takes place; such a process is possible because of a significant difference between boiling and convection Biot numbers. A new quenching technology that allows for the austempering process to be performed in cold liquids is discussed in the article. It is shown that a Liščić/Petrofer probe can be successfully used for investigations of the discovered phenomena and for controlling austempering processes in cold liquids.