Comparison of Flow Behaviors at High Temperature of Two Press Hardening Boron Steels with Different Hardenability

Abstract

The deformation behavior and the constitutive description of materials are important in the design and numerical simulation of manufacturing processes. In this work, the rheological behavior of two quenchable boron steels was derived in the range of interest for the Press Hardening (PH) process. For this study, the following steps were performed: (i) Design of the specimen geometry adopted during the hot tensile tests in the Gleeble®3180 physical simulator. (ii) Performance of hot tensile tests at temperatures between 750 and 850 °C and strain rates of 0.01–1 s−1. (iii) The description of the material constitutive model by means of the Arrhenius-type equation and the comparison between the experimental and predicted data. Firstly, the method was validated on USIBOR®1500 boron steel by means of a comparison with existing literature data, and good agreement with other scientific works was found. Finally, this method was also adopted on USIBOR®2000, a steel that belongs to the new generation of Ultra-High-Strength Steels (UHSS). A comparison between the rheological behavior of these two steels was carried out. The results show that USIBOR®2000 steel exhibits greater strength compared to USIBOR®1500 steel. The Arrhenius constitutive model well predicts the flow behavior of both steels.

Keywords

• mechanical characterization
• quenchable ultra-high-strength steels
• Gleeble system
• Arrhenius-type constitutive equation