Acessibilidade / Reportar erro

Effect of Hot Deformation on Microstructure, Hardness and Precipitation Kinetics in a C350 Maraging Steel Modified by Titanium Addition

Maraging steels are alloys with a good balance between strength and fracture toughness. These properties are obtained by quenching and aging treatments, where the precipitation of intermetallic compounds is promoted in a martensitic matrix. In this context, this paper aims to evaluate the effect of hot deformation on microstructure, kinetics and formation of reverted austenite in a C350 maraging steel modified by titanium addition, in order to improve the mechanical properties without addition of alloying elements. The following characterization techniques were used: optical microscopy (OM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Vickers microhardness and Dilatometry. The results showed that the deformation promoted a refinement of martensitic packages and blocks, proportional to the reduction of height and a preferred alignment towards the center of the sample. In the aging treatment, the deformation accelerated the kinetics of precipitation and formation of reverted austenite. It was also verified a reduction of the volumetric variation produced by reactions and a reduction of precipitation temperature and formation of reverted austenite in the greater deformation.

Keywords:
Maraging; hot deformation; precipitation; reverted austenite; precipitation kinetics


ABM, ABC, ABPol UFSCar - Dep. de Engenharia de Materiais, Rod. Washington Luiz, km 235, 13565-905 - São Carlos - SP- Brasil. Tel (55 16) 3351-9487 - São Carlos - SP - Brazil
E-mail: pessan@ufscar.br