Eventos Anais de eventos
COBEF 2017
Congresso Brasileiro de Engenharia de Fabricação
Diferenças nas propriedades mecânicas das zonas termicamente afetadas (ZTA) em chapas de aço-carbono ASTM A36, soldadas com corrente contínua e com corrente pulsada.
Submission Author:
Priscila Eduarda Kraft Lopes , SC , Brazil
Co-Authors:
Alido Ronchi, Paulo Sembarski, Jean Senise Pimenta, Fernando Gruber Colaço, Marlon Fontanive
Presenter: Alido Ronchi
doi://10.26678/ABCM.COBEF2017.COF2017-0513
Abstract
On this work It was verified the effect of welding with continuous and pulsed current on the microstructure and on mechanical properties of the ASTM A36 steel. For the deposition of the beads, was used a synergic multiprocess GMAW source called Sigma 500, operating in direct and pulsed current. The variables were the current type and values of 190 A and 270 A for continuous and medium pulsed current, the variation of pulsed current was 25%. The welds were made with solid wire AWS-6 E70S, with diameter of 1.2 mm and mixed gas of Ar 75% / CO2 25%, using two voltage levels of 19 V and 32 V for DC. The equivalent pulsed voltage was determined by the equipment, sufficient to melt the required amount of wire provided with the currents used. The plates for the welding of ASTM A36 steel has the dimensions: 4.76 mm thickness, 350 mm width and 500 mm length. The torch angle, welding speed and DBCP were controlled by a welding manipulator. The microstructure, the profile of hardness and morphology of the beads, were characterized. In addition, tensile test and bending test were performed to analyze the mechanical properties of the welds according to the NBR 7438 and NBR 6892. The results showed a microstructure with higher grain refining for the welds made with pulsed current and lower welding energy, obtaining a metal transfer short circuit type. With more weld energy was possible to observe a grain growth due to the heat generated by the spray transfer both when pulsed DC.
Keywords
Soldagem, ASTM A36, Corrente Contínua, Corrente Pulsada, Soldagem, ASTM A36, Corrente Contínua, Corrente Pulsada
