Work function-chemisorption study of hydrogen on iron: kinetics and strain effects

Journal Article · Sat Jan 01 00:00:00 EST 1983 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(83)90044-5· OSTI ID:6924304

Pasco, R W; Ficalora, P J

Work function (surface potential) changes occurring upon adsorption of hydrogen on iron have been measured by the static capacitor method. The effect of applying strain to the iron foil while in equilibrium with the hydrogen ambient has also been determined. The kinetics of dissociative adsorption have been shown to be consistent with control by the surface migration of the adsorbed hydrogen molecule. It has also been shown that straining the iron foil into the plastic region decreases the equilibrium surface concentration of atomic hydrogen, the embrittling species, postulated to occur through the surface migration of atomic hydrogen to strain produced ''catalytically active'' recombination defect sites on the surface. These results are shown to be consistent with observed crack growth kinetics. The effects of pressure, temperature and material strength on Stage II (slow) crack growth kinetics are easily explained with a kinetic model based upon adsorption/desorption kinetics and the experimentally determined effect of plastic strain.

• Research Organization: Syracuse Univ., NY
• OSTI ID: 6924304
• Journal Information: Acta Metall.; (United States), Vol. 31:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HYDROGEN
ADSORPTION
IRON
SURFACE POTENTIAL
STEELS
CRACK PROPAGATION
KINETICS
STRAINS
STRESSES
SURFACE PROPERTIES
WORK FUNCTIONS
ALLOYS
ELEMENTS
FUNCTIONS
IRON ALLOYS
IRON BASE ALLOYS
METALS
NONMETALS
POTENTIALS
SORPTION
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties