Despite the improved strength and toughness, the susceptibility to the hydrogen-assisted delayed fracture limits the use of the high strength steels in the automotive industry. The component strength strongly depends on the hydrogen distribution, and it can significantly drop due to stress-assisted hydrogen migration and accumulation phenomena. Several hydrogen migration models are published in the literature, and some of them are already implemented in finite element software. Nevertheless, the definition of the proper boundary conditions that can model the hydrogen evaporation from specimen surface are still an open issue. In the present study it is presented an experimental procedure to assess the hydrogen desorption form a planar specimen extracted from a sheet metal by measuring the hydrogen content via Hot Extraction Method (HEM). Hydrogen content was measured at increasing time intervals on coupons extracted from the same sheet metal specimen, where hydrogen had been introduced by electrochemical charging. The experimental data were analyzed in the framework of the Fick’s migration model, deriving the value of the hydrogen desorption coefficient.
Boundary conditions modeling in the FE hydrogen migration models in high-strength steels
macoretta g.;monelli b. d.
Primo
Writing – Review & Editing
;bertini l.;valentini r.;bertini l.
2021-01-01
Abstract
Despite the improved strength and toughness, the susceptibility to the hydrogen-assisted delayed fracture limits the use of the high strength steels in the automotive industry. The component strength strongly depends on the hydrogen distribution, and it can significantly drop due to stress-assisted hydrogen migration and accumulation phenomena. Several hydrogen migration models are published in the literature, and some of them are already implemented in finite element software. Nevertheless, the definition of the proper boundary conditions that can model the hydrogen evaporation from specimen surface are still an open issue. In the present study it is presented an experimental procedure to assess the hydrogen desorption form a planar specimen extracted from a sheet metal by measuring the hydrogen content via Hot Extraction Method (HEM). Hydrogen content was measured at increasing time intervals on coupons extracted from the same sheet metal specimen, where hydrogen had been introduced by electrochemical charging. The experimental data were analyzed in the framework of the Fick’s migration model, deriving the value of the hydrogen desorption coefficient.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
