Alloy Layer Formation and Abrasive Wear Property of High Temperature Aluminized Stainless Steels

To clarify the formation of the alloy layers formed on stainless steels during high temperature aluminizing at 900°C in air and the wear properties of the aluminized stainless steels, the abrasive wear tests for 18Cr–8Ni steel, 16Cr steel and 13Cr steel were performed. Observed voids in the alloy layers of stainless steels were less than that of carbon steel. The thicknesses of alloy layers formed during high temperature aluminizing were large in the order of 13Cr steel, 16Cr steel and 18Cr–8Ni steel. The alloy layers of stainless steels aluminized at 900°C for 3 h were consisted of four layers. The FeAl layer tended to have the highest abrasive wear resistance in four layers. The abrasive wear resistance of this layer tended to increase as the content of Cr increased. The abrasive wear resistance of the alloy layers, having the hardness HV <300, increased linearly with increase of hardness. However the abrasive wear resistance of the alloy layers, having the hardness HV >500, tended to decrease as the hardness increases because of the brittle fracture of the alloy layers.