Hydrogen Embrittlement and Internal Friction of Carbon Steel

Abstract

Table 1. Chemical composition of samples. Fig. 1-(a) Size of testing piece. 2-(b) Schematic diagram of the apparatus for measurement of internal friction.

EFFECTS OF HYDROGEN ON THE MECHANICAL PROPERTIES OF STEEL**Prepared in collaboration with E. Gasior.

“…In general, the effect of a given amount of hydrogen is least when it can be evenly distributed over many sites, greatest when it is most highly segregated in a few locations, any one of which may be the site of brittle fracture..." In several low-alloy steels, Hobson and Sykes (1951) found a linear or almost linear decrease of R. A. with increasing hydrogen content. Similar results were observed by Mima and Mizuta (1957) in different carbon steels (0-07 to 0-86% C). During storage of hydrogenized specimens, the greatest changes in the E. F. and R. A. values occurred during the initial stages, when hydrogen evolution was particularly fast; Fig.…”

“…Exceptionally high falls in the impact value were reported by Dubovoi and Romanov (1947) for pearlitic plain carbon steel, and by Mima and Mizuta (1957) for 0-07% carbon steel. The last-named authors observed a complete recovery of the original impact value, after some 16 hr ageing at room temperature.…”