Thermal desorption spectroscopy study of experimental Ti/S containing steels

Abstract

This research studied hydrogen trapping by Ti/S containing precipitates in two experimental steels, C076 and C077. Ingots were hot and cold rolled to sheets of 1·2 mm thickness. Precipitates were formed during a well designed heat treatment. Thermal desorption spectra (TDS) were measured after electrochemical hydrogen charging. C077 and C076 produced low temperature TDS peaks at ∼90 and ∼140°C, with activation energies of ∼34 kJ mol⁻¹, consistent with hydrogen trapping at grain boundaries. C076 had a higher hydrogen content attributable to the larger grain boundary area. C076 also had higher temperature TDS peak at ∼270°C, with an activation energy of ∼58 kJ mol⁻¹, attributed to hydrogen trapping associated with Fe_1·2Ti_0·8S₂ precipitates.