Critical Assessment of the Effect of Atmospheric Corrosion Induced Hydrogen on Mechanical Properties of Advanced High Strength Steel

Abstract

Hydrogen absorption into steel during atmospheric corrosion has been of a strong concern during last decades. It is technically important to investigate if hydrogen absorbed under atmospheric exposure conditions can significantly affect mechanical properties of steels. The present work studies changes of mechanical properties of dual phase (DP) advanced high strength steel specimens with sodium chloride deposits during corrosion in humid air using Slow Strain Rate Test (SSRT). Additional annealed specimens were used as reference in order to separate the possible effect of absorbed hydrogen from that of corrosion deterioration. Hydrogen entry was monitored in parallel experiments using hydrogen electric resistance sensor (HERS) and thermal desorption mass spectrometry (TDMS). SSRT results showed a drop in elongation and tensile strength by 42% and 6%, respectively, in 27 days of atmospheric exposure. However, this decrease cannot be attributed to the effect of absorbed hydrogen despite the increase in hydrogen content with time of exposure. Cross-cut analysis revealed considerable pitting, which was suggested to be the main reason for the degradation of mechanical properties.

An Experimental Investigation of Mechanical Behavior of HY 80 Steel in Corrosive Mediums

“…Tensile strength [8], yielding strength [9], crack propagation [10,11,12], fatigue life [13,14,15] are main mechanical properties that is affect by corrosion when the materials are exposed to aggressive mediums such as acidic [16] and saline [7,17]. Corrosion effect on mechanical behavior of materials were studied experimentally [18] and/or numerically [19].…”

“…In the study, Rudomilova observed that dual phase steel demonstrated a reduction in properties of tensile strength and elongation because corrosion caused a decrease in cross-sectional area of the specimens and pitting was formed. On the other hand, Rudomilova demonstrated that hydrogen absorption for 27 days is inadequate to affect the mechanical properties [8]. Li et al investigated corrosion effect on G250 mild steel used in bridge under stressed and non-stressed cases.…”

Hydrogen-Assisted Cracking in GMA Welding of High-Strength Structural Steel—A New Look into This Issue at Narrow Groove

“…For investigation of hydrogen embrittlement, different test methods exist. Tests regarding the influence of diffusible hydrogen on degradation of different microstructures and steels are mainly carried out on electrochemically hydrogen charged tensile specimens [28][29][30][31]. When it comes to welding, there are numerous self-restraint and externally loaded test procedures for investigating HAC [32,33].…”

Hydrogen Embrittlement of Automotive Ultra-High-Strength Steels: Mechanism and Minimisation

“…Essentially a variation on a conventional tensile test (often abbreviated in the context of hydrogen research to CSRT, or 'conventional strain-rate test'), this involves running a tensile test upon a prefabricated and hydrogen-charged specimen at a strain-rate sufficiently low to allow hydrogen atoms to diffuse to high-stress regions, with a resultant loss of ductility and premature failure. Hydrogen charging can be performed in gaseous hydrogen [141], under atmospheric corrosion conditions [139,142], or, commonly, under imposed electrochemical charging conditions [136,140,143], and can be performed in situ during straining, or ex situ, prior to charging, or with a combination of both. Quantifying embrittlement is typically done via an assessment of the reduction in ductility during hydrogen-charged tests, such as decreases in total elongation at failure, reduction in cross-sectional area of the fracture surface, or the reduction in area under the tensile curve (absorbed energy), or may be assessed through the resultant decrease in test time-to-failure as a result of hydrogen ingress.…”