Effect of combined cold deformation and subsequent heat treatment on the microstructure, texture, mechanical properties and cementite spheroidization in AISI 1070 steel

Abstract

In this study, the effects of thermomechanical heat treatments on two batches of commercial AISI 1070 steel were investigated. Both samples underwent cold rolling and annealing at 600 °C for 30 min, and their microstructure and crystallographic texture were analyzed using XRD, SEM observations, and EBSD measurements. Tensile testing was also conducted to evaluate the mechanical properties of the steels. The results showed that the lamella pearlitic microstructure of both samples was transformed into α-ferrite matrix with spheroidal cementite particles (Fe3C). Sample A exhibited a strong γ-fiber texture parallel to the rolling plane, with a typical cold-rolled texture and high anisotropic characterization dominated by (111) orientation. Sample B, on the other hand, exhibited (111)[12¯1] and GOSS (110) texture components with dominant (111) and (101) grain orientations along the rolling direction. While the yield stress and tensile strength were higher in sample A, sample B had better toughness and elongation properties, indicating that it was more ductile. These findings highlight the importance of controlling heat treatment processes to achieve desired microstructures and mechanical properties in steels and provide insights into the relationship between microstructure, crystallographic texture, and mechanical properties. The results of this research could be useful in optimizing the process and performance of steels in various industrial applications.

Keywords

• Cementite spheroidization
• Subcritical annealing
• Electron backscattered diffraction
• Texture