ColumbusTubi



Steel is the material that was first used in the construction of top-of-the-range frames because of its superior mechanical characteristics, most notably its superior fatigue resistance and a breaking load second only to that of advanced composite materials. Columbus research has always worked towards the customization and development of materials with characteristics intended for cycling use. The results are of international importance.
Columbus’s history is the creation of steels with patented formulations such as the famous Nivacrom.



NIOBIUM

It’s a special micro alloyed steel with Manganese, Chrome, Nickel, Molybdenum and Niobium. In the Columbus research and development tradition it can be considered the evolution from of the Thermacrom and Nivacrom alloy. It’s designed to provide better mechanical properties and greater resistance to atmospheric corrosion than conventional carbon steels. For every top-of-the-line and competition frames where lightness and high reliability are fundamental. Like Vanadium in Thermacrom steel, Niobium increases yield strength by precipitation hardening and acts for refinement of grain size. Thanks to the special Columbus chemical composition, the combined effect of precipitation strengthening, and grain refinement the properties are incredibly increased inith respect. To standard steels. Niobium is a more effective strengthening agent than Vanadium. After mechanical deformation working and drawing, NIOBIUM undergoes a special heat treatment that gives the steel its final characteristics; this heat treatment is designed to minimize the tubes distortion and decarbonization phenomena. Columbus heat treatment results in a super fine high-strength microstructure of bainite, wich means high strength, hardness and long fatigue life.
Mechanical characteristics:
Ultimate tensile strength = 1050 ÷ 1250 MPa
Yeld strength: min 750 MPa
Minimum elongation: 14%


NIVACROM

The Nivacrom steel for the Zona series undergoes a series of processes and treatments, which, after drawing, homogenize the mechanical characteristics of the tube, making it uniform along the longitudinal axis. This makes the fatigue behaviour and weldability of the material excellent.
Mechanical characteristics:
Breaking load = 950÷1050 MPa
Elongation > 10%
Steel is an iron/carbon alloy that, with the addition of several elements such as chrome, nickel, manganese, molybdenum, vanadium, etc., develops specific characteristics such as tenacity, fatigue resistance, workability and insensitivity to overheating.
Why choose steel?
Steel ensures high performance at really low weights. The new alloys, particularly Thermacrom, give a weight close to that of the aluminum alloys, together with a perfectly balancable elastic response, that is appreciated in particular on long traits. Unlike aluminum, steel is substantially stable over time, not requiring onerous maintenance cycles. If properly rust-treated, under normal conditions of use, it has almost unlimited fatigue resistance.
It allows frames to be built with excellent performances, rigid yet comfortable, suitable for any type of use.

Micrography of a standard heat-treated low alloy steel: decarbonization process is visible, the mechanical charateristics of the material are highly decreased
     
Micrography of Columbus NIOBIUM steel: low depth of decarbonization processes grants incredible fine and homogeneous structure, and excellent mechanical characteristics.
 

XCR

In cooperation with Trafiltubi ed Aubert & Duval, the new Columbus seamless tube set in stainless steel named XCr, is created. Starting form a specific request of the military industry, looking for a valid substitute for cadmium plated temper hardening steels which could no longer be produced because of their highly polluting manufacturing process, a new martensitic stainless steel with high content of Chromium and Molybdenum and Nickel as alloy elements which increase the mechanical and weldability characteristics, was created. The martensitic main structure contains traces of austenite that reduces the possibility of crack formation especially during the welding process.
The great weldability properties of the new XCr stainless steel, together with its high fatigue resistance and its extraordinary geometrical stability at high temperatures, make this material the natural element for welded structures, such as bicycle frames. Thanks to the high stiffness/weight and UTS/weight ratios (better than titanium and aluminium alloys) together with the elevated characteristics of corrosion resistance, it is possible to manufacture triple butted tubes to build extremely light and indestructible frames.