Research On Mechanism Of Cracking For Hot-Dipping Galfan Coating

As the hot-dip materials, Galfan has good corrosion resistance. But the Galfan coating will be crack when it deformed, so it is very necessary to study the reason of why the Galfan coating to crack. In this paper, use quantitative bending test to find the reason of the coating cracking, and the coating of hot-dipping Galfan was tested by the SEM, TEM, XRD and XPS, to study coating and interlayers. And the results as follows:Zn,α-Fe,Al13Fe4 and Al-Zn has been found in the interlayer coating;. With the result of TEM, there are some O, S andC in the interlayer, which will impact the binding energy between steel and coating. The O, S and C which in the interlayer, make the coating easier to crack.Under the compressive stress, The cracks never occur in the coating, and the coating became more compact; only the coating by the tensile stress, cracks in the coating will be produced and expansion. When if Galfan coating thickness be more over 100μm, cracking will be more serious degree; the Fe will affect the coating mechanical properties, the coating with Fe will easy to be crack; the drawing process can make the coating more compact and to improve the mechanical properties of the coating.