Study of correlation between the steels susceptibility to hydrogen embrittlement and hydrogen thermal desorption spectro

  • PDF / 1,644,975 Bytes
  • 12 Pages / 595.276 x 790.866 pts Page_size
  • 50 Downloads / 245 Views

DOWNLOAD

REPORT


(0123456789().,-volV)(0123456789(). ,- volV)

ORIGINAL ARTICLE

Study of correlation between the steels susceptibility to hydrogen embrittlement and hydrogen thermal desorption spectroscopy using artificial neural network Evgenii Malitckii1



Eric Fangnon1 • Pedro Vilaça1

Received: 3 September 2019 / Accepted: 14 March 2020  The Author(s) 2020

Abstract Steels are the most used structural material in the world, and hydrogen content and localization within the microstructure play an important role in its properties, namely inducing some level of embrittlement. The characterization of the steels susceptibility to hydrogen embrittlement (HE) is a complex task requiring always a broad and multidisciplinary approach. The target of the present work is to introduce the artificial neural network (ANN) computing system to predict the hydrogen-induced mechanical properties degradation using the hydrogen thermal desorption spectroscopy (TDS) data of the studied steel. Hydrogen sensitivity parameter (HSP) calculated from the reduction of elongation to fracture caused by hydrogen was linked to the corresponding hydrogen thermal desorption spectra measured for austenitic, ferritic, and ferritic-martensitic steel grades. Correlation between the TDS input data and HSP output data was studied using two ANN models. A correlation of 98% was obtained between the experimentally measured HSP values and HSP values predicted using the developed densely connected layers ANN model. The performance of the developed ANN models is good even for never-before-seen steels. The ANN-coupled system based on the TDS is a powerful tool in steels characterization especially in the analysis of the steels susceptibility to HE. Keywords Hydrogen embrittlement  Artificial neural network  Thermal desorption spectroscopy  Hydrogen sensitivity parameter

1 Introduction Susceptibly of steels and alloys to hydrogen embrittlement (HE) is a problem of many aspects. Depending on the material microstructure, stress state, hydrogen diffusivity, and solubility, the mechanism of the hydrogen-induced damage and HE varies. A number of HE mechanisms of damage of the structural steels were proposed such as hydrogen-enhanced decohesion (HEDE) [1, 2], stress-induced hydride formation and cleavage [3, 4], hydrogenenhanced localized plasticity (HELP) [5–7], adsorptioninduced dislocation emission (AIDE) [8, 9] and hydrogenenhanced stress-induced vacancy (HESIV) [10–12]

& Evgenii Malitckii [email protected] 1

Department of Mechanical Engineering, Aalto University School of Engineering, Espoo, Finland

mechanisms. However, in most cases a combination of the mechanisms was involved in the hydrogen-assisted damage of steels that makes complicate the modeling and prediction of the hydrogen-induced crack nucleation and growth. Hydrogen can diffuse into the steels and accumulate during all the stages of the lifecycle of the steels, namely during production at the mills, manufacturing of the structural components, and exploitation. For example, quenching of steels in