Influence of Cu Addition on Microstructure and Mechanical Properties of Fe-0.08C-1Mn-2.5Ni Steel

In addition to precipitation strengthening effect as Cu precipitates in steel, Cu-containing steel is generally believed to have ability to resist corrosion. However, there are some issues, e.g. strengthening mechanism and appropriate copper content, remaining to be clarified. In this presentation, an offshore platform steel Fe-0.08C-1Mn-2.5Ni was used as experimental materials and the emphasis was put on the comparative study of Cu-addition in terms of microstructural evolution and mechanical properties by using microstructural characterization and mechanical properties measurement. The continuous cooling transformation behavior of the two Cu-containing steels with varying contents was first compared. The Cu-containing precipitates were then determined by transmission electron microscopy (TEM) in the hot rolled steel plate after quenching and tempering. Finally, the effect of Cu-addition on precipitation strengthening and low temperature toughness was discussed considering the interaction of Cu precipitates with dislocation and martensite microstructure.