Hi Raghav
Interesting site you linked to
First apologies for my rather rash statement
Quote:Unsealed this should give in excess of 20 years life.
and will edit it to say could instead of should
Estimating/predicting life is difficult due to the number of variable factors like temperature, agitation, composition, dissolve gases, pH etc. along with the fact that in real life cases we have to wait so long for results.
That said I can't help feeling a corrosion rate of 0.137 mm/yr sounds excessive, which would predict 0.250 mm zinc coating lasting only 2 years
Without knowing the exact conditions of testing it is difficult to comment.
I know some of the information we use to predict corrosion rates is from galvanised steel, but generally corrosion rates are based on the amount of zinc and whether applied by hot dip, plating or thermal spray seems to make little difference. One advantage of thermal spray coatings is the ability to use thicker coatings.
Some intersting links which may generate more discussion than answers
(links dead)