Lab samples
We give you some data about the samples that are next to the microscope in the exhibit. What if the word siderurgia (iron and steel industry) comes from sidereal, “coming from the stars”?
Ferrite. It is almost pure iron with silicon and phosphorus impurities. It is the basic component of steel and is the softest, most ductile, malleable and magnetic of steels.
Perlite. A compound formed by alternative sheets of ferrite and cementite. It contains 0.8% carbon. Harder and stronger than ferrite but softer and more malleable than cementite. Its name is due to the irisations it acquires when illuminated, similar to pearls.
Ledeburite: It is not a component of steels but of foundries. It is formed by cooling a liquid carbon melt.
Austenite. It is the densest constituent of steel and is formed by a solid solution of iron carbide, which is ductile, tenacious, soft and resistant to wear. It’s not magnetic. It has great plasticity and is easy to work with (forging, stamping, etc.).
Cement. It is the hardest component of steels with very crystallized molecules and, therefore very fragile.
Martensite. It is a metastable phase, so it does not appear in the diagram. It is the most important component produced by heat treatments designed to produce ideal mechanical properties. It is magnetic, and after cementite is the hardest component of steel. It comes in the form of needles. It’s magnetic.
Widmanstätten: It’s meteorite iron. Approximately 90% of the composition of the core of our planet is iron which is kept in a liquid state by its very high temperature. Earth’s geomagnetism, which determines the magnetic poles, is generated by those deposits of liquid iron that are inside the Earth.
