Quantitative analysis of mixed niobium-titanium carbonitride solubility in HSLA steels based on atom probe tomography and electrical resistivity measurements

Solubility of mixed niobium-titanium carbonitrides in commercially relevant High-Strength Low-Alloy (HSLA) steel was investigated by combined use electrical resistivity measurements and APT after interrupted quenching from soaking temperatures between 950 1250 °C. Increasing the bulk material towards higher proportional to nominal niobium addition which varied 0.002 0.022–0.043–0.085 wt.-%. Correlative analysis solutes matrix showed good agreement with resistivity. Investigating numerous precipitate particles, also derived a precise composition for niobium-titanium-carbonitrides constitute microstructure casting/before soaking. The scavenging microalloy elements insoluble titanium nitrides corrected means such quantitative image estimation total volume fraction nitrides. For first time, solute together were used solubility calculations derive an experimental product. This compared products well-established simple carbides theoretical multicomponent carbonitrides. large discrepancy experimentally modelled emphasizes necessity robust methodology quantification precipitation HSLA steels.