Caracterização microestrutural do aço AISI 4130 amanteigado com ligas de níquel

Abstract

In this work a study was carried out to analyze the microstructural behavior of the braze weld interface of AISI 4130 steel with different nickel alloys. The MIG welding process was used to deposit the buttery. The influence variables were the Inconel 625 (AWS ERNiCrMo-3) and Inconel 725 (AWS ERNiCrMo-15) electrodes; The conventional and pulsed current modes and the stress relief thermal treatment (TTAT). As response variables the macro and microstructures and the microhardness were analyzed in the interface of the buttery with the Thermally Affected Zone (ZTA). The results showed that the conventional current mode has a more unstable arc, therefore the presence of spatter was observed. In the pulsed current mode, a stable arc was observed, with total absence of spatter. The macrostructural analysis showed that the buttery performed with pulsed current had lower levels of dilution than the conventional current mode even with higher levels of welding energy. In addition, it was verified in the micrographic analyzes that the interface of the buttery with pulsed current mode promoted greater control of partially diluted zones(ZPD), minimizing the formation of fragile zones. It was also observed that TTAT was effective in reducing the microhardness of ZTA.