This work aims to study the mechanical properties in the tensile and impact of AISI 1020 steel, to evaluate the effectiveness of the application of laser heat treatments in regions with notches, facilitating the breaking, in these structures, when reaching a certain stress level. This material is used in wind tunnel diaphragms. It is intended to create a well-defined region where the fracture is fragile, with rapid rupture, keeping the adjacent regions ductile, so that, after the fracture, there is deformed material in the vicinity of the broken surface. To facilitate this rupture, a heat treatment and a weld were carried out, in the region of the notch, both with laser, so that later this material could be analyzed.

Laser surface hardening was carried out using an Yb:fiber laser. The microstructure of the laser hardened zone consists of ferrite, a small amount of retained austenitic phase and martensite, with the amount of martensite varying gradually along the depth.