Effect of interrupted boriding on microstructure and mechanical properties of 16MnCr5 steels

OpenAlex İngilizce

The microstructure, microhardness and tensile properties of continuously borided and interrupted borided 16MnCr5 steel were compared. In the continuous process, boriding was carried out continuously at 1273[Formula: see text]K for 16[Formula: see text]h. In the interrupted process, after 5[Formula: see text]h of boriding at 1273[Formula: see text]K, the crucible containing the specimens and the boriding powders was removed from the furnace and cooled to 873[Formula: see text]K in still air for 30[Formula: see text]min and this procedure was repeated three times. Both boriding treatments were achieved in a solid medium using the powder pack method with commercial Ekabor-I powders as the boron source. X-ray diffraction studies indicated the presence of FeB and Fe2B phases in the boride layers for both boriding treatments. The transition zone was more pronounced in the continuously borided steel. The average hardness values of the boride layers were 1759 and 1648[Formula: see text]HV0.1for the continuously borided and interrupted borided steels, respectively. The hardness of the boride layers were considerably higher than the 200[Formula: see text]HV0.1hardness of the untreated steel. No significant difference in tensile properties could be observed between the two different boriding procedures.