摘要
Hydrogen promotes the cleavage fracture of Fe-3%Si alloy. Hydrogen atmosphere moving along with a dislocation will reduce the strain energy of the dislocation, resulting in a decrease in the external stress necessary to operate the F-R source. Thus, hydrogen can promote dislocation multication, which has been verified using a dislocation decoration technique. Fractography and mechanic analysis indicate that a set of the [001] sessile dislocations on the {001}-plane is just a cleavage microcrack. Hydrogen carried by the gliding dislocation will enter the microcrack, and the hydrogen pressure will augment the external stress and reduce the critical number n necessary to form a stable cleavage crack and the number m of the pile-up dislocations. This indicates that hydrogen promotes the formation of the stable cleavage crack before the other slip systems operate.
Hydrogen promotes the cleavage fracture of Fe-3%Si alloy. Hydrogen atmosphere moving along with a dislocation will reduce the strain energy of the dislocation, resulting in a decrease in the external stress necessary to operate the F-R source. Thus, hydrogen can promote dislocation multication, which has been verified using a dislocation decoration technique. Fractography and mechanic analysis indicate that a set of the [001] sessile dislocations on the {001}-plane is just a cleavage microcrack. Hydrogen carried by the gliding dislocation will enter the microcrack, and the hydrogen pressure will augment the external stress and reduce the critical number n necessary to form a stable cleavage crack and the number m of the pile-up dislocations. This indicates that hydrogen promotes the formation of the stable cleavage crack before the other slip systems operate.
