Corrosion Behavior of Laser-Brazed Surface Made by Joining of AA6082 and Galvanized Steel
- National Institute of Technology, Department of Metallurgical and Materials Engineering (India)
- Indian Institute of Technology Kanpur, Department of Materials Science and Engineering (India)
- International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) (India)
In the present study, a galvanized steel and a AA6082 aluminum alloy sheet of 2 mm thick were weld-brazed by applying laser and using 2-mm-diameter solid Al-12% Si filler wire at 2.5 m/min wire feed rate and 2 m/min laser scan speed at varying laser power (4.0, 3.5, 3.0 kW) in flange configuration. The microstructural investigation of the laser weld-brazed joints revealed the presence of two-layered intermetallic compound at steel/braze seam interface. The corresponding x-ray diffraction analysis of the steel/braze seam interface showed the presence of Al-Fe-Si-based ternary intermetallic phases. SEM and EDS analysis of the braze seam revealed the presence of α-Al grains surrounded by Mg{sub 2}Si phase in the grain boundary region. Fine intermetallic layer was observed at lower heat-input condition. The corrosion performance of the brazed joints was studied with the help of immersion, salt spray, and electrochemical polarization tests in different electrolytes containing NaCl salt. Brazed joints experienced galvanic corrosion during immersed in corrosive media. From the salt spray test, it was revealed that galvanized steel was highly susceptible to corrosion compared to Al-rich phase. The polarization results showed a substantial change in corrosion resistance from steel interface to the brazed region due to the variation in microstructure. The samples brazed with low heat-input showed better corrosion resistance as compared to the joints made with high heat-input. Post-corrosion microstructure revealed intergranular corrosion at the brazed joint along with pit formation.
- OSTI ID:
- 22970865
- Journal Information:
- Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 4 Vol. 28; ISSN 1059-9495; ISSN JMEPEG
- Country of Publication:
- United States
- Language:
- English
Similar Records
In Situ SEM Observations of Fracture Behavior of Laser Welded–Brazed Al/Steel Dissimilar Joint
Pulsed TIG Welding–Brazing of Aluminum–Stainless Steel with an Al-Cu Twin Hot Wire
Related Subjects
ALUMINIUM ALLOYS
BRAZED JOINTS
BRAZING
CORROSION RESISTANCE
CRYSTAL LATTICES
ELECTROCHEMICAL CORROSION
ELECTROCHEMISTRY
GRAIN BOUNDARIES
INTERFACES
INTERGRANULAR CORROSION
INTERMETALLIC COMPOUNDS
LASERS
MAGNESIUM SILICIDES
POLARIZATION
SCANNING ELECTRON MICROSCOPY
STEELS
X-RAY DIFFRACTION