Banca de QUALIFICAÇÃO: MARIA EDUARDA LIMA COSTA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIA EDUARDA LIMA COSTA
DATE: 20/05/2026
TIME: 09:00
LOCAL: LIME Sala 2
TITLE:

APLICAÇÃO DO TRATAMENTO POR CORRENTE ELETROPULSADA PARA O AMACIAMENTO NO AÇO DP780

KEY WORDS:

AHSS steels; formability; DP780; electropulsing treatment; phase transformation.

PAGES: 84
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

Given the growing concern about environmental degradation and the global need to reduce greenhouse gas emissions, the energy transition has established itself as a central topic in both academia and large industries. In this context, the automotive industry has been strongly affected by stricter emissions regulations, especially since 2020, driving the development of lighter, more efficient materials. Taking this topic into consideration, one of the most widely used materials for this purpose are Advanced High-Strength Steels (AHSS), as they are known for offering a good combination of strength and formability. Dual-Phase (DP) steels are a part of the AHSS family. They are widely used in industry due to their mechanical properties, which are suitable for structural and safety applications, given their microstructure composed of a ferritic matrix with dispersed martensite islands. However, one of the main challenges associated with these materials is maintaining ductility and local formability in order to prevent the nucleation and propagation of cracks originating from the forming process, which can reduce their service life. Seeking a method that promotes the softening of this alloy in a faster and more sustainable way, this work aims to apply an innovative technology, the electropulsing treatment (EPT). This technique consists of applying electrical pulses with controlled parameters, such as current, cycle period, and application time, to 1 mm-thick DP780 sheets. The samples were characterized by optical microscopy (OM), Scanning Electron Microscopy (SEM-FEG) and X-ray Diffraction (XRD). To assess the effectiveness of the softening and its correlation with the proposed EPT parameters, Vickers microhardness (HV) analysis was carried out. Results demonstrate that EPT produced significant microstructural changes, especially in samples treated at a current density of 60 A/mm², and showed a change in microhardness along the treatment direction, while samples treated at 45 A/mm² exhibited carbide precipitation in the martensite phase, indicating early stages of tempering. Tensile tests will be performed to evaluate the mechanical behavior before and after EPT.

COMMITTEE MEMBERS:
Externo ao Programa - 1652765 - MAURÍCIO MHIRDAUI PERES - nullExterno ao Programa - 1938946 - NICOLAU APOENA CASTRO - nullPresidente - 1350249 - RUBENS MARIBONDO DO NASCIMENTO