Mössbauer effect determination of the influence of laser pulses on phase transformations and redistribution of tungsten in R18 fast-cutting steel

Mössbauer measurements in the backscattering geometry were used to determine the influence of the laser pulse duration on phase transformations and redistribution of tungsten within the zone of laser interaction with R18 quenched fast-cutting steel. The Mössbauer spectra were recorded by counting conversion electrons and x-ray photons. Laser treatment produced a surface layer ~10 µ thick where the phase composition was homogeneous, an increase in the pulse duration reduced the amount of the residual austenite, and as a result of partial dissolution of carbides the solid solution became saturated with tungsten at ~10% and ~14% as a result of interaction with pulses of durations 1.2 and 6.0 msec, respectively.