Effects of mechanical and environment factors on the notch tensile strength of 1300 MPa class SCM435 high strength steel in hydrogen gas

There are several factors of hydrogen gas environment effects on strength of high strength steel SCM435 with a sharp notched specimen. In this paper, tensile tests were carried out in several hydrogen and helium gas environments. The examined factors were the gas pressure, the gas temperature, the crosshead speed and the notch root radius. The result of tensile tests in hydrogen gas environments showed the degradation of tensile strengths at any given environment factors, which were not occurred in helium gas environments. Additionally, as the result of investigating the area of intergranular fracture, it was found that the tensile strength had an inverse proportion with the area of intergranular fracture regardless of several environment factors.