Study on the surface packing cementation aluminizing processes of Q345 steel in an air environment

To address the requirement of a vacuum environment or a protective atmosphere in the process of aluminizing, pack cementation was used to aluminize the surface of Q345 steel in an air environment. The aluminized coating with a large hardness and corrosion resistance was prepared on the surface of Q345 steel. The influence of the aluminizing temperature and the holding time on the surface quality and thickness of the aluminized coating was studied to determine the optimum conditions for aluminizing. The surface quality of the coating was observed by an electron microscope and the thickness of the aluminized coating was measured. The main elemental distribution of the coating was also analyzed by an energy spectrometer. The phase composition of the aluminized coating was analyzed by an x-ray diffractometer and the change in coating hardness was measured by a microhardness tester. The results showed that when the holding time was 3 h and the heating temperature was 800 °C, the obtained thickness of the aluminized coating was 180 μ m, with good quality, excellent hardness, and corrosion resistance.