ON THE NATURE OF SYNERGISTIC INTENSIFICATION OF INTERCRYSTALLINE CORROSION OF AUSTENITE STAINLESS-STEELS BY PHOSPHORUS AND CARBON ADMIXTURES

A synergistic negative effect of phosphorus and carbon admixtures on the resistance of grain boundaries in a tempered austenite steel in the end of the steel passive region is experimentally established, using the data of gamma-spectrometry, atomic absorption spectrophotometry, and X-ray photoelectron spectroscopy in combination with the results of polarization measurements. The effect is caused by a deteriorative influence of phosphorus on the passivability of chromium-depleted boundary zones, and the lower the chromium content, the more pronounced the influence.