Slow strain rate tests

Slow Strain Rate tests can be performed referring to ASTM F 519 and ASTM G129 in order to correlate hydrogen absorption and resulting degradation of mechanical properties, see Figure 14. Tests are carried out on specimens pre-charged in gaseous hydrogen environment (T = RT ÷ 500 °C, p = 1 ÷ 200 bar) and then subjected to tensile test in air with very low strain rate (strain rate 10-4 ÷ 10-5 mm/s). Diffusible hydrogen content is measured at the end of the test.

SSRT in autoclave with high-pressure gas environment and at room temperature may also be tested.