The Effect of Preliminary Thermomechanical Processing on the Kinetics of Localized Plasticity Autowaves in Trip Steel

• Published in: Metals (Basel ) 2020-11, Vol.10 (11), p.1494
• Main Authors: Orlova, Dina V., Danilov, Vladimir I., Gorbatenko, Vadim V., Danilova, Lidiya V., Shlyakhova, Galina V., Zuev, Lev B.
• Format: Article
• Language: English
• Subjects: autowaves; deformation bands; digital image correlation; martensite transformation; thermomechanical processing; TRIP steel
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met10111494

The kinetics of the martensitic transformation fronts in transformation-induced plasticity (TRIP) steel was studied in relation to preliminary thermomechanical treatment using the digital image correlation method. It was found that warm rolling of steel to 40–63% reduction significantly increases the stress of the onset of strain-induced phase transformation and changes the loading curve stages. The strain-induced phase transformation in TRIP steel occurring through the formation of Lüders and Portevin–Le Chatelier bands is shown to be an autowave process of localized plasticity. The austenite → martensite transformation at the elastic-plastic transition occurs in the form of several switching localized plasticity autowaves. At the jerky flow stage, excitation autowaves of localized plasticity are generated and propagate repeatedly until the strain-induced austenite → martensite transformation is completed. It is shown for the first time that the sources of excitation autowaves in the material are the sites of nucleation or annihilation of switching autowaves.