The Effect of Microstructural Characteristics on the Hydrogen Permeation Transient in Quenched and Tempered Martensitic Alloys

Abstract

This work evaluates the permeation curve characteristics for four quenched and tempered generic, ternary alloys, each containing one specific carbide. The different carbides (W2C, Cr23C6, TiC, and V4C3, respectively) are induced by a quench and tempering treatment. The correlation is made between the different microstructural characteristics, including the carbides and the martensitic matrix, and the observed hydrogen diffusivity and thus the permeation transient. The permeation curves, obtained via the Devanathan and Stachurski method, are therefore compared with thermal desorption spectroscopy and hot extraction results. The delay of the permeation transient can be associated with the overall trap density, while the slope is related to the amount of reversible trapping sites. Generally, the obtained hydrogen permeation transient of the different ternary or Fe–C–X materials correlates with the hydrogen trapping ability. The following order of hydrogen diffusion is determined, i.e., Fe–C–V < Fe–C–Ti << Fe–C–Cr < Fe–C–W. The hydrogen trapping ability of the tempered induced carbides plays a decisive role in the value of the hydrogen diffusion coefficient.

Hydrogen Permeation in X65 Steel under Cyclic Loading

“…Figure 3 shows the effect of the cyclic loading on permeation flux. The model proposed by Grabke and Riecke [74,76] was applied for fitting the transient data. More detailed information on data processing is reported in [64].…”

Effects of Alloying Elements (C, Mo) on Hydrogen Assisted Cracking Behaviors of A516-65 Steels in Sour Environments

“…The N T of Steel C, which was higher than expected, was attributed to be due to the high level of irreversibly trapped hydrogen in the steel, as discussed above. In general, the presence of a higher density of irreversible traps in steel is considered to be due to a higher resistance to HIC as the traps with a high hydrogen binding energy immobilize the diffusible hydrogen and suppress the local hydrogen concentrations around potential crack areas [51]. As shown above, however, the HIC resistance of Steel C was much lower than that of Steel B.…”

Effect of Microstructure on Hydrogen Permeation in EA4T and 30CrNiMoV12 Railway Axle Steels

“…Thus, it is believed that these "good" carbides were indeed precipitated in the tempered 30CrNiMo12 steel. V-carbides have been proven to be strong irreversible traps by many researchers [25,30,48]. Recently, Van den Eeckout et al [48] discussed the effect of W 2 C, Cr 23 C 6 , TiC, and V 4 C 3 on hydrogen diffusivity.…”

“…V-carbides have been proven to be strong irreversible traps by many researchers [25,30,48]. Recently, Van den Eeckout et al [48] discussed the effect of W 2 C, Cr 23 C 6 , TiC, and V 4 C 3 on hydrogen diffusivity. Owing to the strongest trapping ability of V 4 C 3 , the Fe-C-V alloy exhibited the lowest diffusivity.…”