Affiliation:
1. School of Materials & Mineral Resources Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
2. Indian Institute of Technology Kharagpur, India
3. Industrial and Production Engineering Department, School of Engineering and Engineering Technology, Federal University of Technology Akure, PMB, Akure, Ondo State, Nigeria
Abstract
Cryo-rolling, a technique of severe plastic deformation (SPD) performed at cryogenic temperatures, has proven to be a promising technique for improving the microstructure and mechanical properties of low-carbon steels. Low carbon steel with a two-phase ferrite-martensite starting microstructure was subjected to cryogenic rolling at liquid nitrogen temperature to produce sheets with different deformation rates: 50%, 70%, and 90%. The microstructure, mechanical properties, and corrosion resistance were investigated. The results show that cryo-rolling effectively refines the microstructure and leads to a higher dislocation density and smaller grain size as the deformation rate increases. The cryorolled sample deformed at 90% has the highest grain aspect ratio (35.5), the smallest crystallite size (13.70 nm), the highest lattice strain (74.6 x 10-3), and the highest dislocation density compared to the samples deformed at 50% and 70%. This refined microstructure significantly improves the mechanical properties, with the cryo-rolled sample deformed at 90% exhibiting the highest hardness (152 HV), tensile strength (1020 MPa), and yield strength (950 MPa), corresponding to an increase of 175.6%, 344.0%, and 466.5%, respectively. In addition, cryo-rolling at 90% showed a decrease in corrosion resistance, with the lowest corrosion rate observed at 90% deformation (5.97 mm/year).
Publisher
National Library of Serbia
Subject
Materials Chemistry,Metals and Alloys,Mechanics of Materials,Geotechnical Engineering and Engineering Geology