Nanostructured Steel Susceptibility to Sulfide Stress Cracking

Wednesday, 4 October 2017: 16:40
Camellia 2 (Gaylord National Resort and Convention Center)
A. Shadravan, R. Case (Texas A&M University), and A. Rumann (VODIK industries)
The susceptibility of a high strength low alloy nanostructured steel to sulfide cracking resistance (SSCC) is assessed. Notch Tensile Slow Strain Rate (NTSSRT) method is used to evaluate the threshold stress intensity values (KISSCC)). The objective is to understand the effect of the microstructure on the susceptibility to SSCC, the control condition is a conventional low alloy carbon steel with a tempered martensite micro structure.

The tests were performed in a brine with 1% NaCl buffered at pH 4.5 with H2S gas with 1% to 100% (mol %) balance N2 at room conditions. The nanostructured steel results of the KISSCC parameter are: 107 Ksi in0.5 at 1% H2S to 42 Ksi in0.5 at 100% H2S. The control condition exhibited 22 Ksi in0.5 at 100% H2S. The evaluation of the relative crack propagation energy suggest that the nanostructured ferrite grains exhibit a much lower susceptibility to SSCC than the tempered martensitic microstructure