FeC, still is good
Cast iron, plain carbon steel, Columbus Nivacrom steel; what's the difference? Generally speaking it's a couple of percentage points here and there. The predominant component of all of these materials is iron (Fe).
Cast iron steel is composed of iron (Fe) and carbon (C) with carbon percentages being 2-4% by weight. Cast irons also contain higher levels of impurities than steel alloys and a large amount of silicon (Si); 1-3% by weight.
Columbus Steel Tubing
Steel by definition is an alloy of iron and carbon in which the carbon content is controlled to be less than 2% and plain carbon steels usually contain less than 1.2% carbon and small quantities of manganese (Mn), copper (Cu), silicon, sulfur (S), and phosphorus (P). Plain carbon steels are designated by a four digit number, e.g.,1020, with the first number specifying the class of the alloy. 1XXXX is for carbon steels while 4XXXX is for chromium based steels. The second number designates the subgroup of the alloy and the last two numbers represent the % carbon in the steel - .2% in the case of 1020.
Alloy steels start as carbon steels with other elements added to specifically improve the mechanical and workable properties of the steel alloy. Perhaps the most famous steel recognized by cyclists is 4130 or chromoly steel. This steel alloy contains measured quantities of both chromium (Cr) and molybdenum (Mo) as strengthening agents. As in the case with plain carbon steels the last two digits represent the amount of carbon in the metal, .3% with the relative amounts of chromium and molybdenum being .8-1.1% and .35-.5% respectively.
“both niobium and vanadium are grain refiners and are used as alloying elements”
The newer, modern steels used for cycling like Columbus Nivacrom or Columbus Niobium offer even higher strength and therefore more performance over their 4130 cousins. These steels contain alloying additions of niobium and vanadium (Nivacrom) or just niobium (Niobium).
Generally speaking both niobium (Nb) and vanadium (V) are grain refiners and are used as alloying elements to increase the mechanical properties of the steel. Both Nivacrom and Niobium steels also undergo proprietary processing and heat treatments that enhance their mechanical properites even further. Ultimately, Columbus Niobium tube sets are mechanically stronger than their Nivacrom counterparts and can be drawn to thinner gauges giving more performance (a lighter frameset).
The big conclusion here is that even though cast iron, plain carbon steel, and cycling tubing share 95% of the same composition; it's that last 5% that makes a huge difference as to whether you're cooking eggs or cooking up a bike frame.
