LOPES, C. M. F.; LOPES, Cássia Maria Farias.
Resumo:
In this work were determined, by the direct method "IN SITU", the
maximum temperatures (Tmax.) and cooling time values between 800 ° and
500 ° C (Ats / 5) in different regions of the thermally affected zone (ZTA) of joints
welded high strength and low alloy steels (ARBL), varying the
welding parameters, and then comparing the values of this welding variable.
thermal cycle obtained experimentally with those obtained through
theoretical expression of heat flux using the specific heat value of the metal
different temperatures, the effects of the variation of
Ats / s values on microstructure and hardness in weld metals and regions
coarse grains and fine grains from the thermally affected zone of joints
soldered under different welding energies and temperatures of
preheating (To). For this purpose a data acquisition system was used with
thermocouples located at different ZTA locations of the joints welded by
Electric Arc with Coated Electrode and Electric Arc with Wire process
Tubular, with preheats of 100 ° C and 200 ° C. The obtained results
indicated significant differences between theoretical and experimental values of To and
Minutes / 5 Variations in cooling time values between 800 ° and 500 ° C
provided by changes in welding parameters did not result in
significant changes in microstructures and hardness of weld metals,
however, they have brought about considerable changes in microstructure and
hardness values of the different regions of the ZTA.
