Transformation of Chemical and Phase Composition in Al/FeAl3(Cr,Ni)/Fe2Al5(Cr,Ni) Laminated Coating at High Temperature Heating

The effect of thermal action at 1100 °C on the kinetics of phase transformations in the coating, obtained by hot-dip aluminizing of 12Cr18Ni10Ti steel, is studied. It was shown that, after 500 h of exposure, the chemical composition is leveled over the entire volume of the sample. Moreover, the predicted retention time of the heat-resistant properties of the coating at 1100 °C is about 2000 h.

Kinetics of Phase Transformations in FeAl(Cr,Si) / Fe3Al(Cr,Si) / Fe(Al,Cr,Si) Laminated Coating on the Cr15Al5 Alloy

The influence of thermal action at 1150 °C on the kinetics of phase transformations in a layered coating FeAl (Cr,Si) / Fe3Al (Cr,Si) / Fe (Al,Cr,Si), obtained using a technology involving aluminizing of an Cr15Al5 alloy by hot dipping in silumin melt AK12M2 and heat treatment. It was shown that after 100 hours of exposure, the visually distinguishable boundary between the coating and the alloy disappears. The aluminum content in the Cr15Al5 alloy increased to 17 at. %, silicon up to 3 at. %, and chromium is reduced to 14 at. %. The microhardness of the alloy increases from 1.6 to 2.4 GPa and survivability at a test temperature of 1150 °C increases from 120 to at least 920 hours.

Axisymmetric Heat Conduction Problem for a Half-Space Covered with a Laminated Coating of Periodic Structure

The paper deals with a stationary heat conduction problem for a microperiodic, two-layered coating on a homogeneous half-space. The distribution of temperature and heat fluxes are obtained within the frame of the homogenized model with microlocal parameters [1,2, and within the framework of the classical heat conduction problem for a periodically layered structure. The influence of number of layers in the coating on the heat flux and temperature is analyzed.