Hydrogen Embrittlement of Submicrocrystalline Ultra-Low Carbon Steel Produced by High-Pressure Torsion Straining
The tensile property and hydrogen embrittlement (HE) behavior in the submicrocrystalline ultra-low carbon steel produced by HPT straining were investigated. Elongated grains with 300 nm thickness and 600 nm length with high dislocation density were formed by the HPT straining at a rotation-speed of 0.2 rpm under a compression pressure of 5 GPa. The engineering tensile strength of the HPT processed ultra-low carbon steel for > 5 turns was 1.9 GPa, which is similar to the value of maraging high-alloy steels. The elongation increased with strain (at 5 to 10 turns), is caused by the reduction of the stress concentration due to the existence of continuously recrystallized grains. HE occurred in the HPT processed specimen for 5 turns with high tensile strength of 1.9 GPa under hydrogen atmosphere. However, its HE was suppressed via recovery process by annealing at low temperature while maintaining the high strength.
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
Y. Todaka et al., "Hydrogen Embrittlement of Submicrocrystalline Ultra-Low Carbon Steel Produced by High-Pressure Torsion Straining", Advanced Materials Research, Vols. 89-91, pp. 763-768, 2010