Steel is one of the most widely used and recycled materials. There are thousands of grades of steel with equally as many applications. There are also different technologies for manufacturing steel, one of which offers a major advantage in the construction industry: cold-formed steel (CFS).
Hot-rolled steel and cold-formed steel are both structural steels used in building construction. Hot rolled steel is made by rolling steel into thin strips or plates. Hot rolling occurs at very high temperatures, above the recrystallization temperature of the material, producing malleable steel that can be formed in a variety of shapes.
Cold-formed steel, also called light gauge steel is made from steel plate, sheet or strip material. Cold-formed steel can be made by roll forming, the method used for mass production, by stamping, commonly used in the automotive industry, or by press braking. Cold rolling is a metal forming process in which a sheet of metal is pressed through a pair of rolls to reduce thickness, increase strength and improve surface finish. The cold rolling process happens at ambient temperature, below the steel’s recrystallization temperature. This process changes the mechanical properties of the steel to produce uniform, lightweight steel with a high strength-to-weight ratio. Cold-formed steel is also easy to fabricate, transport, and install; it is moisture-, fire-, wear- and corrosion-resistant; and it is energy efficient. Read the American Iron and Steel Institute’s Cold-Formed Steel Profile for an in-depth look at the reasons why cold-formed steel is becoming the material of choice in construction.
Study results presented at Quake Summit 2014 in Anchorage, Alaska, part of the 10th U.S. National Conference on Earthquake Engineering, provide another reason why cold-formed steel is an advantageous building material—it appears to be nearly earthquake-proof.
CFS-NEES is a three-year research project funded by the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) and the steel industry to test the ability of buildings made of lightweight cold-formed steel to withstand an earthquake. The research team is composed of scientists from six universities and design consultants from the steel industry, and is lead by researchers from Johns Hopkins University. The researchers constructed a two-story building using cold-formed steel for its primary beams and columns upon a moving platform known as a “shake table” and subjected it to a series of lab-generated high-magnitude earthquakes. The results were surprising—the structure suffered almost no damage. The team hopes to make the data available to building engineers to help them improve the seismic safety of their designs.
These findings will likely increase the demand for cold-formed steel, and steel producers need to ensure their product meets building material specifications. To achieve high quality steel strip, thickness gauges are used to detect and correct deviations in thickness in real-time. X-ray gauges are the optimal thickness gauge technology to provide the speed and accuracy required to operate a cold rolling mill. X-ray based sensor systems provide extremely accurate high speed/low noise measurements, permitting producers to realize material savings and quality improvements.
Read this Optimization of a Cold Rolling Mill with a High Speed X-ray Thickness Gauge paper to learn about other advantages of an x-ray-based thickness sensor.