Preliminary communication
The Influence of Quenchant Composition on Cooling Rate
Ljiljana PEDIŠIĆ
; Maziva-Zagreb Ltd, Member of INA Group, Zagreb, Croatia
Božidar MATIJEVIĆ
; University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb, Croatia
Jasminka MUNIĆ
; Maziva-Zagreb Ltd, Member of INA Group, Zagreb, Croatia
Abstract
Correct selection of quenching media decreases the risk of tensile stresses,
and also cracking and workpiece distortion. High-performance quenching
oil must have excellent oxidation and thermal resistance and low sludge
formation, must be non-staining and have an elevated flash point and
acceptable heat-transfer characteristics. The quenching media contain base
oil and different types of additives according to application requirements.
As the base oil, it is possible to use mineral oils, synthetic and natural oils
separately or in combination. Mineral base oils are widely used because of
their advantages in stability in comparison to natural oils, or lower prices
in comparison to synthetic oils. There are numerous compounds available
for use but, besides functional properties, the environmental and safety
requirements have a strong influence on components selection. Based on
that the barium additives must be replaced with less harmful compounds.
Petroleum derivatives should be changed with renewable base stocks
that are biodegradable, as the general trend in lubricant development. By
changing the composition of quenching oils, base oils and additives, heat
transfer characteristics are also changed. In this study the examination
results of physical-chemical properties and also cooling characteristics
of new quenching oils with different compositions are presented. Cooling
curves for different compositions have been evaluated according to ISO
9950 standard.
Keywords
Hardening; Metal heat treatment; Quenchants
Hrčak ID:
74525
URI
Publication date:
28.2.2011.
Visits: 1.771 *