CHARACTERIZATION OF THE INFLUENCE OF HIGH-PRESSURE HYDROGEN GAS ON THE DUCTILITY OF THE STEEL 15 MNNI-6-3

Constant extension rate tests on smooth tensile specimens were used to evaluate the sensitivity of the normalized low-alloyed carbon steel 1 5 MnNi 6 3 to hydrogen embrittlement. The experiments were performed a t ambient temperature, in pure hydrogen gas, in hydrogen gas with diff erent admixtures of oxygen, or in argon at a gas pressure of 9 MPa. In comparison with the characteristics obtained in argon, a considerable decrease of the reduction of area took place in pure hydrogen gas. Th is effect was diminished by increase of the oxygen content in the hydr ogen gas. The absorbed specific energy up to fracture was reduced due to hydrogen by a factor of about 7 compared with the value obtained in argon.