Mossbauer studies of Fe-Si-C system structure changes by laser and ultrasound treatment

The influence of simultaneous laser irradiation and ultrasound on the phase structure of the Fe-Si-C system (grey cast iron) was studied by means of M ossbauer spectroscopy. It has been found that the efficiency of the ultraso und influence depends on the melted layer depth (temperature). Ultrasound a ffects the phase structure of the melted volume, though in the surface laye r, which is of the highest temperature, it does not alter the amount of mar tensite and iron carbide. The major affects of ultrasound are assistance in dissolving carbon and in disintegrating oversaturated gamma-Fe(C) solution . It is shown that structures similar to the structure of the solid Fe(C) s ystem should originate in the melted state.