Hydrogen embrittlement of high-strength marine steel as a weld joint in artificial seawater under cathodic polarization

2022 ◽  
pp. 106044
Author(s):  
Hongchi Ma ◽  
Liyang Sun ◽  
Hong Luo ◽  
Xiaogang Li
Keyword(s):  
Hydrogen Embrittlement ◽  
Weld Joint ◽  
Cathodic Polarization ◽  
High Strength ◽  
Artificial Seawater

Effects of Cathodic Protection on Cracking of High-Strength Pipeline Steels

2010 ◽  
Author(s):  
M. Elboujdaini ◽  
R. W. Revie ◽  
M. Attard
Keyword(s):  
Hydrogen Embrittlement ◽  
Cathodic Protection ◽  
Cathodic Polarization ◽  
Water Solution ◽  
Reference Electrode ◽  
High Strength ◽  
Point Of View ◽  
Pipeline Steels ◽  
Different Levels ◽  
Reduction Index

A comparison was made between four strength levels of pipeline steels (X-70, X80, X-100 and the X-120) from the point of view of their susceptibility to hydrogen embrittlement under cathodic protection. The main aim was to determine whether the development of higher strength materials led to greater susceptibility to hydrogen embrittlement. This was achieved by straining at 2×10−6 s−1 after cathodic charging in a simulated dilute groundwater solution (NS4) containing 5% CO2/95% N2 (pH approximately 6.7). The results showed quantitatively the loss of ductility after charging, and the loss of ductility increases with strength level of the steel. All four steels exhibited a loss of ductility at overprotected charging potential and an increasing amount of brittleness on the fracture surface. Ductility in solution was measured under four different levels of cathodic protection, ranging from no cathodic protection to 500 mV of overprotection with respect to the usually accepted criterion of −850 mV vs. Cu/CuSO4 reference electrode. Experiments were carried out by straining during cathodic polarization in a simulated dilute ground water solution (NS-4 solution). Strain rates used were 2×10−6 s−1. After failure, the fracture surfaces were characterized by examination using scanning electron microscopy (SEM). Under cathodic protection, all four steels showed loss of ductility and features of brittle fracture. The loss of ductility under cathodic polarization was larger the greater the strength of the steel and the more active (i.e., more negative) the applied potential. The Ductility Reduction Index (DRI) was defined to quantify the reduction in ductility.

scholarly journals Effect of Strain Rate on the Hydrogen Embrittlement Property of Ultra High-strength Low-alloy TRIP-aided Steel

2019 ◽  
Vol 105 (4) ◽  
pp. 443-451 ◽  
Author(s):  
Tomohiko Hojo ◽  
Riko Kikuchi ◽  
Hiroyuki Waki ◽  
Fumihito Nishimura ◽  
Yuko Ukai ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Strain Rate ◽  
High Strength

Implementation of HSLA-100 Steel in Aircraft Carrier Construction—CVN 74

1995 ◽  
Vol 11 (02) ◽  
pp. 97-101
Author(s):  
J. P. Christein ◽  
J. L. Warren
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength ◽  
High Yield ◽  
Aircraft Carrier ◽  
Implementation Plan ◽  
New Material ◽  
Welding Procedure

High strength low alloy (HSLA)-100 steel was developed to be less sensitive to hydrogen embrittlement than high yield (HY)-100 steel. The primary benefits sought through the use of this new steel were savings in energy, labor, and scheduling that would result from reduced preheat for welding. This paper reviews the overall efforts required to implement the use of HSLA-100 steel during CVN 74 aircraft carrier construction. It discusses the engineering and design effort required to incorporate a new material on a vessel midway through construction. Also included is a discussion of the development of an implementation plan which ensures successful welding procedure qualification, production welding, and inspection of HSLA-100 welds. Results confirm that HSLA-100 steel can be successfully substituted for HV-100 steel in a shipyard environment, and that significant benefits can be realized from reduced welding preheat. Also, key elements of future applications of HSLA-100 are presented.

scholarly journals Quantitative tests revealing hydrogen enhanced dislocation motion in α-iron

2021 ◽  
Author(s):  
Long-Chao Huang ◽  
Dengke Chen ◽  
De-Gang Xie ◽  
Suzhi Li ◽  
Ting Zhu ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength Steels ◽  
High Strength ◽  
Dislocation Motion ◽  
Atomistic Simulations ◽  
Vacuum Degassing ◽  
Nucleation Barrier ◽  
Free Behavior ◽  
Individual Dislocation ◽  
Energy Transportation

Abstract Hydrogen embrittlement jeopardizes the use of high-strength steels as critical load-bearing components in energy, transportation, and infrastructure applications. However, our understanding of hydrogen embrittlement mechanism is still obstructed by the uncertain knowledge of how hydrogen affects dislocation motion, due to the lack of quantitative experimental evidence. Here, by studying the well-controlled, cyclic, bow-out movements of individual screw dislocations, the key to plastic deformation in α-iron, we find that the critical stress for initiating dislocation motion in a 2 Pa electron-beam-excited H2 atmosphere is 27~43% lower than that under vacuum conditions, proving that hydrogen lubricates screw dislocation motion. Moreover, we find that aside from vacuum degassing, dislocation motion facilitates the de-trapping of hydrogen, allowing the dislocation to regain its hydrogen-free behavior. Atomistic simulations reveal that the observed hydrogen-enhanced dislocation motion arises from the hydrogen-reduced kink nucleation barrier. These findings at individual dislocation level can help hydrogen embrittlement modelling in steels.

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