Phenomena Discovered During Immersion of Steel Parts into Liquid Quenchants (Overview)

Abstract

In the paper, new phenomena are discussed which were discovered during investigation of the intensive quenching processes. It is shown that in many cases film boiling is prevented completely during quenching of steel parts in cold liquids, especially in water salt solutions. In this case, the part surface temperature drops almost immediately to the liquid boiling point at the beginning of the quench and then maintains at this level for a relatively long time, i.e., the so-called self-regulated thermal process is established. A simple equation for determining the duration of the self-regulated thermal process is proposed. Thermal waves are generated during an immersion of steel parts into a cold liquid and after the self-regulated thermal process is completed. The thermal waves move in opposite direction from where the cooling process starts. The self-regulated thermal process was used to develop an original intensive quenching technology (IQ-2 process). It can be a basis for developing other new technologies such as an austempering and a martempering in cold liquids under pressure. Discovered effects of thermal waves can be used for determining a duration of the self-regulated thermal process and for reconstructing an existing theory on the double electrical layer. Practical examples of calculations of the duration of the self-regulated thermal process are provided in the paper.