Speaker
Srinivasulu Grandhi
(Ph. D Research Scholar)
Description
This study investigates the effect of manganese addition in the galvanized zinc coating on steel.
Manganese possesses more negative electrochemical potential than both zinc and iron. In addition,
manganese can also provide sacrificial protection to iron like zinc. A stepwise process was used
to prepare the required bath composition for coating due to a very high melting point of manganese
than that of Zn. Initially, Zn-Mn master alloy was prepared in a resistance-heated furnace
and then the master alloy was diluted in the molten zinc bath for the required coating composition. The dipping of steel sheets in zinc alloy bath was carried out after preparation of surface by degreasing, pickling, fluxing, and drying. The microstructures of the coated sheets were observed by Scanning Electron
Microscopy, and the electrochemical tests were performed in 3.5wt. % NaCl solution. The results
show that the Mn addition reduces the corrosion current density by half, and red rust was not
observed on the Zn-Mn-Al alloy coated steels even after 336 hours of salt spray test.
Keywords
Hot-dip galvanization, Zn-Mn-Al alloy coating, Electrochemical test, Salt spray test
Author
Srinivasulu Grandhi
(Ph. D Research Scholar)
Co-authors
Prof.
Raja V. S.
(Professor)
Prof.
Smrutiranjan Parida
(Associate Professor)