## 4 Results
### Winch  
The XRF analysis of the winch drum revealed that the grey cast alloy was composed mainly of iron (95.1-96.3 weight percentages (wt%) Fe), with a low percentage of silicon (2.6-3.8 wt% Si) (ground metal, Table 2). The presence of 0.5-0.9 wt% Mn and up to 0.5 wt% of P and Ti were also detected (Table 2). Based on VT, LM, and SEM observations, the material of the drum was identified according to ASTM A247-67 [40] as type B grey cast iron (Figures 2-5) with a carbon content of above 2 wt% C. The drum's conventional metallographic (Figure 2c) and FMM (Figure 3a and Supplementary Material Figure S3a, respectively) metallographic observations showed dendritic morphology with a heterogeneous microstructure containing areas of ferrite (matrix), perlite, iron phosphide (Fe\({}_{3}\)P) eutectic (bright areas), graphite flakes (black thin elongated particles), and flower-like graphite rosettes (round clusters of black graphite flakes arranged perpendicular to a central point) (Figures 2-5 and Supplementary Material Figures S3-S6). \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Composition (wt\%)**} \\ \cline{2-7}
**Measured Area** & **Fe** & **Si** & **P** & **S** & **Mn** & **Ti** \\ \hline \hline \multicolumn{1}{c}{Futtock plate, centre, area 5 (Figure 1c and Supplementary Material Figure S2b)} & 99.4 & 0.3 & 0.2 & - & - & 0.1 \\ \hline \hline \multicolumn{1}{c}{Cast stud-link chain controller, side wall, area 1 (Figure 1d,e and Supplementary Material Figure S1b, L-CS)} & 96.0 & 1.9 & 1.5 & - & 0.4 & 0.2 \\ \hline \hline \multicolumn{1}{c}{Cast stud-link chain controller, side wall, area 2 (Figure 1d,e and Supplementary Material Figure S1b, L-CS)} & 96.5 & 1.9 & 1.0 & - & 0.4 & 0.2 \\ \hline \hline \multicolumn{1}{c}{Cast stud-link chain controller, side wall, area 3 (Figure 1d,e and Supplementary Material Figure S1b, L-CS)} & 97.0 & 1.2 & 1.3 & - & 0.3 & 0.2 \\ \hline \hline \multicolumn{1}{c}{Cast stud-link chain controller, side wall, area 3 (Figure 1d,e and Supplementary Material Figure S1b, L-CS)} & 96.7 & 2.3 & 0.7 & - & 0.3 & - \\ \hline \hline \multicolumn{1}{c}{Cast stud-link chain controller, side wall, area 3 (Figure 1d,e and Supplementary Material Figure S1b, L-CS)} & 97.6 & 2.0 & 0.4 & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 2: Conventional metallographic light microscope (LM) images of the winch drum (L-section): (**a**,**b**) grey cast iron with dendritic pattern containing black graphite flakes and graphite rosettes (before etching); (**c**,**d**) grey cast iron with black graphite flakes surrounded by ferrite grains and pearlite at ferrite grain boundaries and iron phosphide eutectic (after etching). Figure 4: Conventional metallographic SEM images of the winch drum after grinding, polishing, and etching (L-section): (**a**) general view of grey cast iron—areas in squares analysed by EDS; (**b**) typical area of grey cast iron containing black graphite flakes; and (**c**,**d**) ferrite matrix, graphite flakes (black), iron phosphide eutectic (bright microstructure)—areas in squares analysed by EDS. Figure 3: Field multi-focal metallography (FMM) LM images of the winch drum (upper part of the drum, L-CS, area 1, after etching): (**a**,**b**) general view of grey cast iron with dendritic pattern; (**c**,**d**) higher magnifications showing black graphite flakes surrounded by ferrite grains and pearlite at grain boundaries and iron phosphide eutectic. The SEM-EDS analysis of the conventional metallographic samples of the drum revealed that the grey cast alloy (Figure 4a, areas 1 and 2, and Figure 4d, area 1) was mainly composed of iron (95.0-96.0 wt% Fe) with low percentages of silicon (2.6-2.8 wt% Si). Other elements were also detected, including 0.9-1.1 wt% manganese (Mn), 0.2-1.0 wt% phosphorus (P), and up to 0.2 wt% of titanium (Ti), sulphur (S), and copper (Cu) (Table 3 and Supplementary Material Figure S4). The SEM-EDS analysis of single black flakes showed that they were composed of 100 wt% carbon.