Mathematical Modeling of Surface Heat Flux During Quenching

Abstract

In this article, a method to model the heat flux during quenching has been developed to bring out the effect of initial soaking temperature. Quench probes with a diameter of 20 mm and a length of 50 mm were prepared from 304 L stainless steel. These probes were quenched from different initial soaking temperatures ranging from 400°C to 950°C in water. Time-temperature data were recorded during the quenching. The heat flux and temperature at the quenched surface were estimated based on the inverse heat-conduction method. The computation results showed that the peak in the heat flux increased with an increase in the initial soaking temperature of the probes. The heat flux was dependent on the initial soaking temperature. A model for the surface heat flux was proposed as a function of dimensionless parameters. The model could be used to compute the heat flux at different surface temperatures and was specified as a boundary condition to simulate the quenching for the particular material-quenchant combination. The model was verified by running a direct quenching simulation with heat fluxes computed at different surface temperatures using the proposed model as a boundary condition in ANSYS, a commercial finite element program.

A Review of the Boiling Curve with Reference to Steel Quenching

“…Thereafter, heat flux keeps decreasing during cooling. At this point, it is convenient to say that Babu et al [11] proposed a normalized boiling curve to represent all curves for different soaking temperatures into a single curve. In spite of its usefulness, this method has not gained further visibility in the research community.…”

Experimental estimation of temporal and spatial resolution of coefficient of heat transfer in a channel using inverse heat transfer method

“…Thus, the inverse problem is ill-posed. Regularization techniques are utilized to alleviate this problem (Babu & Kumar, 2010;Ozisik & Orlande, 2000;Rao, 1996). One of the regularization methods for direct prediction of Nusselt number (Farahani & Kowsary, 2014) is the conjugate gradient method with an adjoint equation.…”

Numerical simulation of cooling process for metal cylinder by gas-liquid medium flow moving horizontally in annular channel

“…В работах [1,2] для модельного описания процесса охлаждения между потоком среды и высокотемпературной поверхностью в качестве замыкающих соотношений используют уравнения для расчета коэффициента теплоотдачи. В работах [3][4][5] приводятся результаты построения и исследования математических моделей процесса охлаждения металлических тел, нагретых до высоких температур, в которых тепловой поток на границе нагреваемого тела известен [3] или определяется уравнением Ньютона-Рихмана [4,5]. В работах по численному моделированию теплового состояния материала и исследованию влияния интенсивности охлаждения на структуру сталей в систему уравнений входят замыкающие зависимости в виде тепловых граничных условий третьего рода [6].…”