Primary and secondary carbides in high-speed steels after conventional heat treatment and laser modification

Complex structure examinations were performed on high-speed steels of different grades obtained using conventional metallurgy and produced by application of powder metallurgy. Hot hardness measurements were focused on the secondary carbide precipitation. Transmission electron microscopy and X-ray diffraction studies established the type of primary carbides and the amount of retained austenite. Scanning electron microscopy examinations were used to calculate the volume fraction of primary carbides. The contribution of the applied heat treatment and laser modification by diode laser remelting to the residual stress state was studied. Energy filtering was used to study the secondary carbides of nanometer size.