Enhancement of Mechanical Properties in Bainitic Steel Processed from Different Austenitization Temperatures

Abstract

A novel high strength steel has been thermo-mechanically controlled processed (TMCP) with 750 8C finish rolling temperature followed by air cooling. Subsequently, the air-cooled steel is partially and fully austenitised separately prior to isothermal bainitic treatment (IBT) followed by air cooling. TMCP steel reveals a congregation of ferrite-bainitemartensite microstructure resulting in an effective combination of strength and ductility. After IBT, multiphase microstructures comprising ferrite, carbide-free lath microstructure (martensite and bainite), and retained austenite up to 12% are obtained which may be due to combined addition of Si and Al. The attractive combination of yield strength (575-699 MPa), tensile strength (1252-1262 MPa), and total elongation (14-16%), as well as continuous yielding behavior, are suitable for structural and automotive applications.

The Effect of Carburization and Repeated Heat Treatment with Different Solutions on the Fatigue Resistance of Medium Carbon Steel

“…One of the most vital difficulties in machine part design is ensuring longevity and dependability [2]. Because of their superior mechanical qualities and low cost, Alloys based-Fe are the material of choice for the automotive industry [3]. Numerous researches have mostly focused on alloys based-Fe to improve their characteristics in gear steel [4][5][6].…”