Reduction of Residual Stress for High‐Strength Low‐Alloy Steel Strip Based on Finite Element Analysis

Abstract

Intensive cooling technology is widely utilized in the production of high-strength hot-rolled steel strip. However, intensive cooling at high cooling rate may cause stress heterogeneity on a steel strip, which further generates great residual stress and influences steel strip shape. In this study, a three-dimensional finite element (FE) model of high-strength low-alloy steel strip on the run-out table coupled with heat transfer, phase transformation, and strain/stress is developed by ABAQUS software. To enhance modeling precision, several experiments are conducted, such as uniaxial tensile test at multiple temperatures, dynamic continuous cooling transformation, and scanning electron microscopy, to determine the material properties and boundary conditions of the FE model. Four new models are established based on this model to reduce the residual stress of strip by modifying the initial and boundary conditions. Results show that reducing the initial transverse temperature difference is the most effective in reducing residual stress, followed by sparse cooling, edge masking, and posterior cooling.

Effect of Ultrasonic Treatment on Microstructure and Properties of 2000 MPa Ultra-High-Strength Steel-Welded Joints

“…Upon increasing the treatment frequency to 25 kHz, both sides of the concave curve formed by the impact exhibit outward deformation of the weld metal and some areas show tiny cracks. Excessive ultrasonic frequency can lead to the destruction of the surface structure of the weld, which in turn affects the mechanical properties of the joint [35].…”

Effect of Plate Surface Conditions on Accelerated Cooling Performance

“…Flatness is influenced by austenite transformation which is also related to temperature, as it is not instantaneous, and the final phases have different specific weights than the original austenite. This is one of the causes of residual stress in the plate, and the resulting strain depends on the formed constituents: pearlite/ferrite mixture, bainite and martensite [8,9]. Figures 9 and 10 [9] show the volume change and the consequences of tensile stresses.…”

Homogeneous cooling control technology for high-strength low-alloy hot-rolled strip

“…For instance, the edge masking technology has attracted widespread attention for its low cost of equipment modification and high operability. Zengshuai Qiu et al [13] found that the internal stress of the strip edge decreased by 33.20 MPa for a 0.2 m masking width and increased by 26.88 MPa for a 0.3 m masking width compared to no masking. Delin Tang et al [14] investigated the transverse temperature distribution of the strip to different edge masking widths by numerical simulation, indicating that the temperature difference between the edge and middle was the smallest with the masking width of 40 mm.…”