Heat treatment effect on composition of Kh12G14N4Yu2M steel surface layers

Redistribution of Kh12G14N4Yu2M steel components in surface layers of samples, annealed in non-oil vacuum 10-7 mm Hg for 2-22 h at the temperatures 500-1100 deg C, has been studied using the method of Auger-electron-spectroscopy and a device with semispherical four-net analyzer produced by ''BALZERS'' firm. Sample surface etching is realized by its bombardment with argon ions with the energy 920 eV at current density 10μA/cm2 and Ar pressure 1x10-4 mm Hg. Etching rate under the above-mentioned conditions constituted approximately 1000 A/h. It is shown, that annealing of Kh12G14N4Yu2M steel in vacuum at the temperatures above 500 deg C results in the appearance of ferromagnetic layer on its surface due to (γ→α)-transformation, tahing place there. In its turn, the phase transformation is a consequence of manganese evaporation from steel during heating in vacuum, which is caused by a high diffusion mobility of manganese in iron as compared with chromium. There is no noticeable redistribution of the rest steel components