The　effects　of　chromium　addition　on　the　corrosion　resistance　of　Fe-3.5B　alloy　in　liquid　zinc　bath　at　520　degrees　C　have　been　investigated.　The　results　show　that　the　matrix　of　as-cast　Fe-3.5B　alloy　transforms　into　alpha-(Fe,　Cr)　solid　solution　while　the　eutectic　Fe2B　changes　into　M2B-type　boride　gradually　with　the　increasing　chromium　addition.　The　corrosion　resistance　of　Fe-3.5B　alloy　can　be　greatly　enhanced　by　5　wt.%　chromium　addition　that　still　maintains　the　netlike　structure　of　boride　in　it.　EDX　analysis　reveals　that　the　Cr　element　can　enrich　in　the　Gamma-Fe3Zn10Crx　(x=1.09　to　1.37)　phase　of　the　interface　to　hinder　the　diffusion　of　zinc　atoms　favorably.　The　Cr　addition　has　no　effect　on　the　Vickers　hardness　of　delta　and　zeta　in　the　corrosion　layer　basically.　Corrosion　mechanism　of　Fe-3.5B　alloys　with　various　Cr　additions　includes　the　following　processes:　the　superficial　dissolution　of　Cr　at　the　interface,　dissolution　of　the　Cr-depleted　zones　of　the　matrix　corroded　by　liquid　zinc,　and　the　spalling　of　boride　which　lost　the　supporting　role　of　the　matrix　completely.　The　corrosion　process　is　mainly　controlled　by　the　diffusion　of　liquid　zinc　atoms.　Crown　Copyright　(C)　2011　Published　by　Elsevier　B.V.　All　rights　reserved.