Rivet (wrought iron) from the supporting structure of a church, year of construction ca. 1900
| Chemical designation | Niet (Puddeleisen) aus dem Tragwerk einer Kirche, Baujahr ca. 1900 |
|---|---|
| Etching | 3 % Nital und grün QT |
The riveted joint from the massively rusted supporting structure of an approx. 120-year-old church was ground in the center. The fiber flow is more prominent after etching with Green QT than with Nital.
The rivet contains approximately 0.2% C, 1.5% Si, 2% Mn, 0.2% P, and 0.1% S, and the microstructure consists of Widmannstätten ferrite. The abundant inclusion lines are two-phase solidified slag: FeO (light) in an Fe-Mn silicate (dark), which also contains phosphorus and traces of Al, S and Ca. Presumably, the rivet with its high slag content was still made from wrought iron (puddling).
The carrier plates contain about 0.03% carbon and much less non-metallic impurities, the mechanical properties correspond to a modern S275JR. The microstructure is ferritic with very little pearlite.
