The Effect of Deep Traps in Hydrogen Solubility and Diffusion in a Quenched and Tempered Steel

The microstructure, and the tensile and electrochemical properties of a quenched and tempered high resistance steel are investigated aiming to develop a suitable material for application in the oil and gas industry. Nanometric Mo, V, W-carbides, and Nb(C,N), together with larger cementite particles are part of the microstructure. Hydrogen permeation tests in different levels of cathodic current show that the steel exhibits high H solubility. Thermal desorption spectroscopy (TDS) shows three peaks corresponding to activation energies 26, 82 and 67 kJ/mol. The higher energies are related to deep traps associated to the nanometric precipitates. Tensile tests in high-H content specimens indicate that the steel has a significative resistance to embrittlement in this steel.