Análise da influência da camada refundida nos valores de energia absorvida nos corpos de prova para ensaio mini Charpy

Abstract

Eletrical Discharge Machining is a non-traditional manufacturing process that has been both very studied and used for decades. One of the main characteristics of this process is the possibility of machining high-hardness materials and creating pieces with complex geometries. EDM is highly indicated in the manufacture of Charpy test specimens, particularly for mini-size Charpy. However, the recast layer, intrinsic to the process, may be a problem to test results behavior. This work investigate the influence of recast layer thickness on the energy absorbed by the specimens during the mini-size Charpy test. The samples are 1.5 mm x 1.5 mm with dimensional variation of 0,01 mm and radius of 0,01 mm. The studied material P110 was manufactured by wire-cut. Several specimen preparation processes were carried out such as sanding, polishing and etching, as well as statistical treatment for selection of samples, which were measured through photos obtained by an optical microscope with high approximation. Basically, the study graphically displays the values of the recast layer thickness, the absorbed energy and the relation between them, showing that there is no influence of the thickness of the recast layer in the mini-size Charpy test results of samples manufactured with P110 steel and the dimensions mentioned above.