Effect of high-pressure hydrogen on crack growth in carbon steel

Abstract

The effect of high-pressure hydrogen and temperature on crack growth was studied in wedge-opening-load (WOL) samples of a low-carbon steel. At temperatures above 280 ‡C, a hydrogen pressure of 3 ksi gave an increasing amount of acceleration in crack growth. These conditions approached but were below that needed to give hydrogen attack (HA) in the surrounding matrix. The value of da/dt increases exponentially with temperature, and Q is roughly equal to that for grain boundary diffusion. The growth is absent at K1 = 0 but varies little with K1 above 15 MPa√m. The value of da/dt increases steadily with hydrogen pressure in the range of 3 to 21 MPa. © 1991 The Minerals, Metals and Materials Society, and ASM International.