Al based coating on martensitic steel

Aluminum based coatings on low activation martensitic (LAM) steels were formed by using CVD method at 973 and 1013 K. After coating, the cleaned specimens were oxidized in 0.133 Pa oxygen atmosphere at 973 and 1013 K to form the Al2O3 layer on the surface. The typical coating thickness of the aluminized layer is 20 μm, a 10 μm thick external layer and a 10 μm thick internal layer. The thickness of the Al2O3 layer is about 1 μm. The microstructure, micro-hardness profile, composition depth distribution in the cross section of the coating and the electrical resistivity of the layers were measured. The results indicate that the coatings on Chinese low activation martensitic (CLAM) steel have higher micro-hardness and higher density than that on EUROFER-97 steel produced at 1013 K. The Al2O3 layer formed at 973 K has higher micro-hardness and higher density than that formed at 1013 K.