For repair welding of tools, laser technology has recently been used with major benefits such as localized heating effect, narrow heat effected zone and negligible undercuts. In this paper, the technology of thermal cracks repair (grooving, welding) with pulsed Nd:YAG laser is described. A micro-hardness analysis of areas surrounding cracks, grooves and welds has been performed, also. The test results suggest that it is relatively fast and easy to eliminate the fatigue area surrounding the cracks, and with proper welding to reestablish the tool operability.
COBISS.SI-ID: 10714651
The thermal fatigue resistance of different hot-work tool steels was studied; AISI H11 and H13, special tool steel and 18% Ni maraging steel. An innovative apparatus for thermal fatigue testing is developed to study the thermal fatigue resistance. The microstructure, hardness profile and the surface cracks developed are analyzed. The specimens of special geometry and optimal set of testing parameters are developed using finite element modeling to improve testing efficiency. The best thermal fatigue resistance achieved special tool steel due to its high thermal stability.
COBISS.SI-ID: 10290971