Experimental and Simulation Study on the Effect of Reduction Pretreatment on the Void Healing of Heavy Plate

Abstract

In addition to eliminating voids in a billet, the reduction pretreatment (RP) process can refine the austenite structure after reheating and can deform the residual voids, which affect the void healing behavior during insulation before rolling, and then can affect the final quality of the steel plate. In this study, the effect of the RP process on the evolution of voids in billets and steel plates was investigated by experimental and numerical simulation. RP and non-RP billets were reheated and rolled into 60 mm-thick steel plates, respectively, and the evolutionary behavior of voids within the plates was analyzed using ultrasonic flaw detection methods. Finite element method (FEM) and phase-field method (PFM) were used to investigate the mechanism behind improving the quality of steel plates under the RP process. The simulation results show that, in addition to directly closing the voids through plastic deformation, the RP process can promote the diffusive healing behavior during insulation before rolling by refining the reheated austenite organization and by increasing the curvature of the void surface. Due to the reduction in voids inside the steel plate, the impact energy of the RP steel plate is higher.

Effects of Deformation Penetration and Recrystallization on the Internal Quality of Casting Ingot

“…Liu et al [ 17 ] investigated the HTRP process with different amounts of reduction and found that as the reduction amount of the HTRP sample increased, the size of recrystallized austenite grains significantly decreased, leading to an improvement in internal segregation. Furthermore, Ning et al [ 18 ] studied the improvement mechanism of the internal quality of steel plates in the HTRP process through finite element and phase‐field methods. They found that in addition to austenite refinement, increasing the curvature of the void surface can facilitate the diffusive healing behavior.…”

Modular Finite Element Modeling of Heavy Plate Rolling Processes Using Customized Model Reduction Approaches

“…An interesting approach is a process presented as "Hot Core Heavy Reduction Rolling", the properties of which are discussed in [16][17][18][19] based on numerical and analytical studies and experimental data. In addition to simulating void healing in heavy plates, by deploying FE and phase-field simulation [20], the hot rolling of clad plates has also received increased attention recently, as numerical and experimental work shows [21][22][23]. Despite these achievements, one aspect still needs to be reflected: the existing models focus on individual passes rather than on the assembly of whole rolling schedules.…”