WSEAS Transactions on Heat and Mass Transfer
Print ISSN: 1790-5044, E-ISSN: 2224-3461
Volume 12, 2017
Mechanism of Film Boiling Elimination During Quenching Probes in Mineral Oils Containing Oligomeric Additives
Authors: , , , ,
Abstract: It has been shown by authors that an addition of the special additive to mineral quench oils for example a polyisobutylene oligomer (PIB), creates an insulating layer on the surface of steel parts during quenching. This insulating layer eliminates the film boiling process on the part surface without affecting physical properties of the oil. The insulating layer decreases an initial heat flux density which becomes less than critical one. The paper presents results of the detailed investigations of the mechanism of the film boiling elimination or its cardinal decreasing due to a presence the small amount of the PIB in mineral oils. Experiments were conducted using an Inconel 600 probe of 10 mm in diameter and 30 mm long, which was quenched from 810oC in Industrial oils (I-8A, I-12A and I-20A). An effect of the oil viscosity and molecular weight of the PIB was investigated by authors. It was shown that by eliminating of the film boiling during quenching, it is possible to govern the intensity of cooling and to provide a uniformity of the hardening process. A phenomenon on eliminating of the film boiling process due to a presence of the small amount of the PIB in the mineral oil is called an EFB effect, which has an important practical use.
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Pages: 93-99
WSEAS Transactions on Heat and Mass Transfer, ISSN / E-ISSN: 1790-5044 / 2224-3461, Volume 12, 2017, Art. #12