AISI 4340 membrane function

Fig. 8.5 The atomic hydrogen permeation transition through an AiSi 4340 membrane as a function of time for different appiied cathodic potentiais in an eiectroiyte containing 0.5 M HCi04 and 0.25 M NaCi04 (pH 0.3) and the membrane thickness=0.3 mm [3]. Reproduced by the permission of The Eiectrochemicai Society.

Fig. E8.1 Plot of as a function of the hydrogen permeation current through an AISI 4340 steel membrane of 0.01 cm thick.

Study of AISI 410 stainless steel, the membrane was spontaneously charged in acidified NaCl. The transients (///oo as a function of T = Dt/L ) were shown to be independent of membrane thickness, indicating that hydrogen permeation was controlled by diffusion but not whether a constant concentration or a constant flux best represented the input boundary condition. 

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