In Situ and Ex Situ TEM Analysis of the Copper Precipitation in Martensitic Steel

Abstract The conventional and in situ transmission electron microscopy imaging of quenched 1.5 pct Cu steel has shown that Cu phases are present even before aging and do not disappear after typical aging times. The 9R precipitates appear after 15 minutes of heating, but they are more noticeable after longer processing times. This suggests that the precipitation mechanisms in carbon steels deserve further analysis, especially because of the inevitable increase in the Cu content in the steel ingots.