AES study of underclad cracking

The present work deals with the occurrence of underclad cracks in three types of steels differing in the contents of the alloying elements (Cr, Ni, Mn) and in the impurities level (As, Sb, Sn). The presence of the intercrystalline fracture typical for the underclad cracks was proved to be dependent on the temperature and on the ageing time. It follows from the results of Auger electron spectroscopy, that the sulphur and phosphorus segregations accompanied by a higher number of carbide (possibly sulphide) particles cause a decrease of grain boundary strength. Segregations of other impurity elements were not detected at grain boundaries.