A study on the susceptibility of high strength tempered martensite steels to hydrogen embrittlement (HE) based on incremental step load (ISL) testing methodology

Effect of hydrogen embrittlement and non-metallic inclusions on tensile fracture properties of 55CrSi spring steel

“…The Vickers hardness obtained for Φ4.0 and Φ4.7 specimens are HV 563 and HV 537, respectively. The Vickers hardness has an important role in deciding the susceptibility to hydrogen embrittlement [25]. It is proposed that Vickers hardness of high strength steels is over HV400, hydrogen embrittlement occurs more markedly [21].…”

The role of plasticity and hydrogen flux in the fracture of a tempered martensitic steel: A new design of mechanical test until fracture to separate the influence of mobile from deeply trapped hydrogen

“…On a macroscopic scale, the consequences of hydrogen can be characterized by a decrease of the mechanical properties including fracture strain, fatigue life and changes of the fracture mode [3][4][5]. These effects have been reported by many studies on several alloys such as nickel base alloys [6][7][8], stainless [9][10] and martensitic steels [11][12][13]. From a phenomenological point of view, without considering the case of the formation of hydrides, HE can be explained by three models.…”

A fast fracture approach to assess hydrogen embrittlement (HE) susceptibility and mechanism(s) of high strength martensitic steels

“…Thus, understanding the hydrogen (H) induced fracture mechanism(s) of these materials is challenging in spite of the availability of extensive literature on their susceptibility [1,[9][10][11][12][13][14]. In general, the susceptibility of a Q & T steel to HE could be related to the mechanical properties such as yield strength, toughness, hardness etc.…”

“…Additionally, the time to evaluate the HE susceptibility metrices is also quite significant, using each of the above test methods. For instance, utilizing some of the available and developed incremental step load (ISL) test protocols based on ASTM F1624 are notably slow, consuming 15 to 48 hours for each test [1,13,25]. In contrast, the proposed test method involves cathodic pre-charging of H followed by a four-point bend test at a relatively higher loading rate of 445 N/min, which remarkably reduces the test time.…”

“…Fig.20. Shows a typical fracture surface from a 4-point bend test with the critical regions (adapted from the author's prior publication in[13]). …”