The influence of the applied type of cooling after eight-stage hot compression test on the structure and mechanical properties of TRIPLEX type steels

The aim of the work was to analyse the impact of an eight-stage hot compression process carried out on the Gleeble3800 simulator, with three cooling variants after thermo-mechanical treatment of Fe-Mn-Al-C steels for their structure and mechanical properties. Performed research allowed to evaluate the impact on the structure and properties of simulation conditions for multi-stage rolling of difficult-to-treat thermomechanical steels for which this treatment is the final process of obtaining ready-to-use high-strength construction steels. Applied thermo-mechanical treatment causes that the main process of removing the effects of strain hardening is dynamic recovery, and static and metadynamic recrystallisation taking place after the last deformation but also between successive deformations, which was also confirmed on the basis of structural analysis of the tested steel after different cooling variants. As a result of the eight-stage hot compression test, the ferrite changed its distribution from fine grains occurring at the boundaries of austenite grains after forging, to elongated grains in a perpendicular direction to the compression direction. Isothermal heating at 850°C for 30s resulted in obtaining a fine-grained structure, statically or metadynamically recrystallised. The maximum tensile strength of the tested steels is about 1250 MPa, and the total elongation value is about 27%.

[1]  A. Chiba,et al.  High-temperature deformation behavior and microstructural characterization of high-Mn bearing titanium-based alloy , 2018 .

[2]  A. Haldar,et al.  Current state of Fe-Mn-Al-C low density steels , 2017 .

[3]  L. Dobrzański,et al.  Influence of high strain rates on the structure and mechanical properties of high‐manganes austenitic TWIP‐type steel , 2016 .

[4]  M. Oechsner,et al.  Ein Verfahren zur Ermittlung der Rissentwicklung während des Feuerverzinkens , 2016 .

[5]  R. Song,et al.  Evolution of the microstructure and mechanical properties of an austenite–ferrite Fe–Mn–Al–C steel , 2015 .

[6]  R. Rana.  Low-Density Steels , 2014, High-Performance Ferrous Alloys.

[7]  J. Seol,et al.  Alloy Design, Combinatorial Synthesis, and Microstructure–Property Relations for Low-Density Fe-Mn-Al-C Austenitic Steels , 2014 .

[8]  D. Raabe,et al.  High strength and ductile low density austenitic FeMnAlC steels: Simplex and alloys strengthened by nanoscale ordered carbides , 2014 .

[9]  Dierk Raabe,et al.  Rapid alloy prototyping: Compositional and thermo-mechanical high throughput bulk combinatorial desi , 2012 .

[10]  K. Ishida,et al.  High-strength Fe–20Mn–Al–C-based Alloys with Low Density , 2010 .

[11]  Ohjoon Kwon,et al.  New Trends in Advanced High Strength Steel Developments for Automotive Application , 2010 .

[12]  Georg Frommeyer,et al.  Microstructures and Mechanical Properties of High‐Strength Fe‐Mn‐Al‐C Light‐Weight TRIPLEX Steels , 2006 .

[13]  Pascal Jacques,et al.  Metallographic methods for revealing the multiphase microstructure of TRIP-assisted steels , 1998 .

[14]  Chanmin Kim.  Professional Ethics , 1912, Buffalo medical journal.