Uticaj zaštitnog gasa na žilavost metala šava legure AlMg4.5Mn dobijenog postupkom zavarivanja cirkulacijom

Abstract

Analiziran je uticaj zaštitnog gasa, na žilavost metala šava aluminijumske legure AlMg4.5Mn dobijenog MIG/MAG postupkom zavarivanja. Za merenje žilavosti je korišćeno instrumentirano Šarpijevo klatno sa mogućnošću razdvajanja energije nastanka i energije rasta prsline. Za MIG/MAG zavarivanje korišćene su četiri različite zaštitne atmosfere: čist Ar, kao i mešavine gasova Ar + 0,0307 % O2, Ar + 30 % He + 0,0317 % O2 i Ar + 48 % He + 0,0290 % O2. Metalografska ispitivanja su urađena da bi se ispitala pojava grešaka i poroznosti metala šava, a žilavost metala šava je ispitana na različitim temperaturama (20, - 90, - 196 °C). Na ovaj način je dobijen sveobuhvatan uvid u uticaj zaštitnog gasa na žilavost metala šava kao najkritičnije oblasti zavarenog spoja legure AlMg4.5Mn.

The effect of MIG/MAG shielding gas on the toughness of aluminium alloy AlMg4.5Mn weld metal has been analyzed using the instrumented Charpy pendulum for standard toughness testing. The MIG/MAG welding was performed in the shielded atmosphere of Ar, as well as the mixtures of gases Ar + 0.0307 % O2, Ar + 30 % He + 0.0317 %O2 and Ar + 48 % He + 0.0290 % O2. Metallographic tests have been performed in order to check the appearance and porosity of the weld metal, as well as its toughness testing at different temperatures (20, - 90, - 196 °C), using the instrumental Charpy pendulum, in order to separate the crack initiation and crack growth energy. In this way, a comprehensive insight of the effect of shielding gas on the weld metal toughness has been obtained.