Thermal Behavior of a Rod during Hot Shape Rolling and Its Comparison with a Plate during Flat Rolling

Joong-Ki Hwang

doi:10.3390/pr8030327

Abstract

The thermal behavior of a rod during the hot shape rolling process was investigated using the off-line hot rolling simulator and numerical simulation. Additionally, it was compared with a plate during the flat rolling process to understand the thermal behavior of the rod during the hot rolling process in more detail. The temperature of the rod and plate during the hot rolling process was measured at several points with thermocouples using the rolling simulator, and then the measured temperature of each region of a workpiece was analyzed with numerical simulation. During hot rolling process, the temperature distribution of the rod was very different from the plate. The temperature deviation of the rod with area was much higher than that of the plate. The variation in effective stress of the rod along the circumferential direction can induce the temperature difference with area of the rod, whereas the plate had a relatively lower temperature deviation with area due to the uniform effective stress on the surface area. The heat generation by plastic deformation during the forming process also increased the temperature deviation of the rod with area, whereas strain distribution of the plate during flat rolling contributed to the uniformity of temperature of the plate with area. The higher temperature deviation of the rod along the circumferential and radial directions during the shape rolling process can increase the possibility of occurrence in surface defects compared to the plate during flat rolling.

Highlights

Most steel products are manufactured by the hot rolling process because the hot rolling process is one of the most efficient plastic forming processes in metal forming industries
On the basis of the comparative studies on the temperature distribution of the a workpiece plate rolling and rod rolling via an off-line simulator and numerical simulation, followingduring major
On the basis of the studies on the temperature distribution of a workpiece during hot plate rolling rodcomparative rolling via an off-line simulator and numerical simulation, the following conclusions were and drawn: On the basisand of the comparative studies on the temperature distribution of a workpiece during hot plate rolling rod rolling via an off-line simulator and numerical simulation, the following major were drawn: 1.conclusions

Summary

Introduction

Most steel products are manufactured by the hot rolling process because the hot rolling process is one of the most efficient plastic forming processes in metal forming industries. In this process, the initial large and thick material, which is called slab, bloom, and billet, is changed to the desired shape by passing through two counter-rotating rolls in the temperature range of 900–1200 ◦ C. The plate is deformed under the plain strain condition, i.e., two-dimensional (2D) deformation This different deformation behavior between the two processes may induce different thermal history between plate and rod, leading to the different microstructures and mechanical properties between the two processes

Methods

Results

Discussion

Conclusion