Abstract
The thermomechanical processing of certain AHSS still represents a challenge due to the lack of complete data on their hot deformation behaviour. Therefore, the aim of this study was to provide data on the hot-working behaviour of four model steels of the type 0.17C-3Mn-1.5Al and 0.17C-5Mn-1.5Al with or without Nb microaddition. The paper presents the results of hot strip rolling simulated by multi-step compression tests using a Gleeble simulator. Analysis of microstructural features of steels with focusing on Mn and Nb contents was carried out using X-ray, LM (light microscopy) and SEM (scanning electron microscopy). It has been shown that the applied deformation schedule allows to develop very fine-grained transformation products of supercooled austenite and controlled cooling with isothermal holding at 400°C enables to retain from 13 to 18% of retained austenite with the blocky or lath-type morphology. Mn alloying in the amount of 3 to 5 wt.% does not affect hot deformation resistance contrary to Nb microaddition, which raises flow stress levels. Influences of Mn and Nb on the retained austenite content and its carbon content are discussed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
