Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
EFFECT OF LASER POWER MODULATION ON POROSITY AND RESIDUAL STRESSES OF SAE 1020 AND 4140 STEEL WELDS
Submission Author:
Francisco Cavilha Neto , SC , Brazil
Co-Authors:
Francisco Cavilha Neto, Milton Pereira, Marcio C. Fredel, Luiz Eduardo dos Santos Paes
Presenter: Francisco Cavilha Neto
doi://10.26678/ABCM.COBEM2021.COB2021-1292
Abstract
The use of a laser with continuous wave (CW) emission as an energy source in welding has revolutionized the industry due to its highly concentrated energy, precision, and versatility. The energy control by the laser through adequate use of hardware and software apparatus has opened up a range of possibilities regarding the beam-piece interaction times and power. In this sense, the present study aims to evaluate the effect of laser power modulation in order to observe the differences and possible improvements from the method in the welding process. The objectives of this work were, mainly, to use different parameters and modulation formats to evaluate some general aspects of the welds such as welding depth, porosity, and residual stresses in two different SAE steels, 1045 and 4140. The pulse frequency was varied to assess, in terms of integrity, the weld morphology as well as the presence of porosity. To analyze the residual stresses through the drilled-hole method combined with speckle interferometry, continuous and modulated welds were produced in SAE 4140 steels plates. The results showed that the power modulation provoked several changes in the morphological characteristics and defects in weld beads produced, reducing porosity and residual stresses.
Keywords
Laser welding, Welding defects, pulsed laser, welding residual stress, Porosity, penetration depth
