Análise da utilização do laser cladding como meio de recuperação de aço ferramenta

Abstract

In this work the parameters of the laser cladding process were evaluated in layers deposited with H13-A powder. The layers were deposited on TENAX300 tool steel substrates and further characterized by optical and scanning electron microscopy and determined the microhardness values in the cross section. A laser machine model PRECO SL 8600 was used. Fraunhofer CoAx 8 nozzle with a spot size of 2 mm and continuous feeding. The laser is of type HPDL. The samples for deposition were 150x47x14 mm with bevels of 25x47x2 mm. Strands with na average width of 1.4 mm were deposited, with a distance between passes of 1.1 mm. It was found that the optimized parameters of the laser deposition process allowed for a correct filling of the chamfer. A homogeneous layer was formed, with little dilution and HAZ and few defects such as pores and lack of fusion. The size, morphology and distribution of the acicular martensite (AM) and the tempered martensite (TM) varied due to the thermal effect between the cladding layers and the laser energy. Higher hardness values were obtained near the surface of the layers, averaging 570 HV0.5, which was lower near the interface, but always higher than the TENAX300 substrate.