Defect Formation in Aluminum-coated Steel by Heat Treatment

A carbon tool steel plate was coated with an aluminum foil a thickness of 100 μm by explosive welding. This aluminum-coated heat-treated in the temperature range 973−1273 K for up to 3.6 ks atmosphere form Fe-Al alloy layer on surface. The basically composed Fe2Al5, two kinds FeAl (Al-rich and Fe-rich FeAl), Fe3Al containing (Fe3Al(C)) ferrite stabilized diffusion (α-Fe(Al)). FeAl2 also detected together Fe2Al5 at more than 1223 K. At 1273 K, island-shaped Fe3Al(C) produced α-Fe(Al), FeAl/α-Fe(Al) interface became indistinct. In addition, defects like crack void were observed vicinity FeAl. purpose present study is investigate reason defect formation. Various heat treatments conducted steel, it found that temperature-rising step responsible consideration got support from results two-step treatment, which heating process immediately after holding 600 s near eutectoid Fe-C binary system.