With our newly developed “twist and bend” test, now we can determine a steel’s resistance to the corrosion phenomenon of stress-oriented hydrogen-induced cracking (SOHIC), even for small specimens. Optimal for materials with challenging geometries (e.g. of transverse samples in pipes), which can now be analyzed too. In the SOHIC-specific “twist and bend” test, a four-point bending specimen, in addition to being bent along its length, is also twisted in a test clamp and then stored in a corrosive medium together with the complete jig. In many cases, it was difficult or impossible to extract large enough specimens from a material sample.
Based on the SOHIC test principle, we developed and successfully verified a test for small specimen dimensions (140 mm x 15 mm 5 mm).
The development of this new method is being accompanied by active participation in the creation of a NACE test standard for analyzing a material’s resistance to the SOHIC corrosion phenomenon. What can lead to this corrosion phenomenon? The combination of corrosion under absorption of hydrogen and stress conditions in the material can lead to stress-oriented hydrogen-induced cracking (SOHIC) in unalloyed and low-alloy steels. As a result, cracks initiative in the material, where the orientation of the individual cracks is aligned with the stress conditions in the material.
More information about our range of corrosion tests you can find here.