Integrated fluid-thermal-structural numerical analysis for the quenching of metallic components

Abstract

The quenching of a metal component with a channel section in a water tank is numerically simulated. Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling, nucleate boiling and convective cooling processes to calculate the difference in heat transfer rate around the component and then combining with the thermal simulation and structure analysis of the component to study the effect of heat transfer rate on the distortion of the U-channel component. A model is also established to calculate the residual stress produced by quenching. The coupling fluid-thermal-structural simulation provides an insight into the deformation of the component and can be used to perform parameter analysis to reduce the distortion of the component.Quenching is a common manufacturing process to obtain unique service performance properties of metallic parts by controlling the amount and the morphology of micro-structural constituents. As it is a complex multi physics problem, it is essential to couple fluid, thermal, phase transformation, microstructural and mechanical behaviour to describe the unusual complex phenomenon. The phase transformation during quenching and the final phase constituents result in different microstructures, which depend on cooling rate and chemical composition of the steel. The cooling rate at part surface highly depends on the flow and the thermo-physical properties of quenchant and the thermo-chemical reactions occurring at the interface. Non-uniform heat transfer and phase transformation associated with large temperature gradients can lead to the difference in variation of volume (expansion or contraction) within component and, as a result, produce high residual stresses in quenched steels. The internal stresses can produce distortion and even cracking. Each of the phenomena included in the quenching process and the coupling of some individual physical problems has been addressed by numerical methods [1][2] . There are a number of simulation works focusing on phase transformation, microstructure, residual stress and mechanical behaviour [2][3][4][5][6][7] . Due to the studies on the theory and the numerical simulation of the individual events that occur during quenching and the computational method for fast and accurate prediction of the multi-physical phenomenon in the last three decades, the simulation of quenching process became realistic and several commercial software packages had been developed to be capable of simulating quenching process, such as DANTE, DEFORM-HT, FORGE, HEARTS, SYSWELD and Quench Simulator. However, most studies consider the quenching process as a thermalmicrostructural-mechanical problem [1][2] and these software are incapable of coupling with dynamic characteristics of fluid in quenching tank, which determines the local cooling rate at part surfaces.Coupling quenching simulations with computational fluid dynamics (CFD) is a major interest [8][9] . However, fluid-thermal simulation in most of the research is focused on single phase l...

Optimization of Roller Velocity for Quenching Machine Based on Heat Transfer Mathematical Model

“…The transient heat transfer within the plate during quenching can be described mathematically by an appropriate form of Fourier's heat conduction equation (1). The equation can be expressed in its most general form as…”

“…Quenching is a common manufacturing process to obtain unique service performance properties of metal by controlling the amount and the morphology of microstructural constituents [1]. Roller-type continuous quenching machine is an important device which is commonly used in quenching heat treatment of plate in the iron and steel industry.…”

An Efficient Fluid-Dynamic Analysis to Improve Industrial Quenching Systems

“…The success of fluid flow simulations was further boosted by more powerful and available computer facilities. In the present decade, new contributions appeared that solved, simultaneously with CFD equations, the transient heat conduction equation to determine the temperature evolution of a solid body within the computational domain [10][11][12][13][14][15][16][17][18]. References [13,14,18] also solved the corresponding solid-phase transformation kinetic equations, and in [13,18], the residual stress and deformation were additionally computed.…”

“…In this way, the authors could obtain a heat transfer coefficient that changed with both the position on a solid surface and time. References [11][12][13][16][17][18]] moved a step forward by simulating boiling heat transfer using the mixed fluids approach. This method considers two intermixed or interpenetrated fluids (vapor and liquid) with the space-dependent void fraction of every phase.…”

“…Srinivasan et al [12] implemented their laminar flow model in the commercial code AVL-FIRE (the AVL-designed 3D CFD software package) to simulate the temperature evolution of a solid plate dipped at a given velocity in static water in a laboratory container. The quenching of an "S"-shaped part was reported in [13]. The authors computed the solid-fluid heat flux from a balance between the heat required to evaporate, quench and facilitate liquid convection according with the heat flux partitioning model, the so-called Rensselaer Polytechnic Institute (RPI) model of subcooled boiling, implemented in the Fluent code.…”