IF-Ti steel C was galvanized after classical or reactive annealing treatment (1.b and 1.c).
No wetting problems or surface flaws due to possible poor surface cleaniless have been
encountered.
Solute carbon enrichments in the grain boundaries leads to a better control of the Fe/Zn
reactivity in the zinc bath while in presence of a superficial pearlite layer, the reactivity is
intermediate as shown by the coating Fe content evaluations (table 3).
Reference and DDQ-BH carburized grade having a lower reactivity were submitted to a
galvannealing treatment at 480 °C for 20 s and 30 s respectivelly. The adherence of the
alloyed coating was evaluated by cup test measurements. For equivalent Fe content
(9.5 %) and coating weight (35 g/m²), the coating of both steel grades has an excellent
adherence as shown by their low average powdering level of 22 mg/cup