The Effect of Agitation and Quenchant Temperature on the Heat Transfer Coefficients for 6061 Aluminum Alloy Quenched in Distilled Water

Abstract

A 6061 aluminum alloy probe was quenched using a Center for Heat Treating Excellence probe-quenching system in distilled water while varying bath temperature and the agitation level. Time versus temperature data were collected during the quench using a thermocouple embedded inside the probe. The surface heat transfer coefficients as a function of temperature were calculated using the Newtonian cooling approximation. The maximum heat transfer coefficient values ranged from 1054 W/m2⋅K for 100°C water with no agitation to 3822 W/m2⋅K for 5°C water with the agitation of 1850 r/min. The data also showed that at higher levels of agitation and lower bath temperatures, the maximum heat transfer coefficient increased.

Influence of Heat Transfer Coefficient on Quenching Processes Simulation

“…There are different approaches for HTC determination as most commonly used are Lumped-heat-capacity method [1][2][3][4][5][6] and Temperature gradient method [5][6][7][8][9][10][11][12][13][14][15]. A feature of these methods is the need for initial information about how the temperature changes with time at one or several points in the bulk of the object being cooled.…”