Affiliation:
1. Materials and Mechanical Engineering Unit Centre for Advanced Steels Research University of Oulu Box 4200 FI-90014 Oulu Finland
2. Centre for Material Analysis University of Oulu FI-90014 Oulu Finland
Abstract
New steel alloying concepts are designed in order to produce a fully ferritic, low‐alloy steel with high (1 GPa) ultimate tensile strength (TS). A simulated hot‐deformation process of the Ti–Mo–V–Nb and Ti–Mo–V steels is designed for that purpose, and the strengthening mechanisms of the steels are evaluated after the isothermal dwell at three different temperatures (590, 630, and 680 °C). The TS and the yield strength (YS) of the test alloys are estimated via hardness measurements. Results show that the estimated TS of over 1000 MPa and YS of over 900 MPa can be achieved in both steels, although the contribution of different strengthening mechanisms to the YS varies between the steels. The effect of the dislocation strengthening can especially compensate the reduced effect of the precipitation strengthening at all tested coiling temperatures (CTs). Based on the results, a CT range of 590–630 °C with the 1800 s dwell time seems to be a potential process window for the studied steels after the present thermomechanically controlled processing (TMCP) route.
Funder
Companhia Brasileira de Metalurgia e Mineração
Business Finland
Subject
Materials Chemistry,Metals and Alloys,Physical and Theoretical Chemistry,Condensed Matter Physics