Fig. 2: Ferrite and pearlite morphologies: (a) ferrite in Fe-0.46 steel that forms layer tracing the austenite grain boundary contours [34], (b) equiaxed ferrite in a Fe-0.4C steel [33], (c) ferrite in low carbon steel [33] (α = ferrite, P = pearlite). The white etching is ferrite while the dark-etching isP.
The steels for this study are S355J2+N (J2N), S355G10+M (G10) and S355G8+M (G8) with compositions as given in Table 2. The composition of J2N was extracted from [35]. They are marine steels having low carbon contents with the microstructures consisting of very small volume fraction of P in a α matrix [36]. Fig. 3 shows the phase morphologies of the microstructure of the J2N.
Table 2: Chemical compositions and mechanical properties of test materials (see [36])
(CE = carbon equivalent)