The world’s largest steel maker, ArcelorMital, has a new nanostructured steel which is not inherently lighter, but it’s so strong that automakers can use thinner gauges and that’s where part of the weight savings comes from. Another part of the weight savings comes from not having to use additional brackets, gussets or panels to strengthen the structure.
A-pillars are becoming so big these days due to roof crush standards that they are actually becoming a safety hazard. The fat A-pillars can partially block your view to side traffic or pedestrians. But with this nano steel, A-pillars could be made much thinner with no sacrifice to structure or safety.
The new steel is not cheaper than other grades of steel. In fact, it’s probably a little bit more expensive. But by eliminating all those brackets and extra panels, the total tooling cost of a car goes down, and that’s where the costs savings comes from.
To get the maximum 188-pound reduction in the BIW, an automaker would have to design-in the nano steel’s capabilities using a clean sheet approach. But ArcelorMittal says that some applications, especially cross-members, lend themselves to running changes on existing designs.
The nano steel does require a newer manufacturing technique called hot stamping. That’s where automakers heat up the steel blanks that go into a stamping press to the point where they’re literally glowing red. Then they feed the red hot blanks into a press and stamp them into body panels. Heating up the steel makes it much more pliable and enables it to be formed into more complex shapes. Actually, this is a fairly common process already in use today, used to form the high-strength steels that have been available for the last decade and a half. So, while the nano steel requires hot stamping, it’s not as if automakers need to make a big investment in manufacturing technology.
There are also whispers of a new breakthrough coming in aluminum. It’s called covitic aluminum, where somehow they impregnate aluminum with carbon fiber.
Details on Nanostructured Steel
Industrial giants like Nippon Steel, Sandvik, Arcelor Mittal, Exxon, JFE Steel and others are all working on nanostructured steel. There is a good chance for broader industrial adoption over the next few years. There are new players such as QuesTek Innovations, Max Planck Institute for Steel Research, MMFX Technologies and Cambridge University who are able to demonstrate significantly greater benefits in nanostructured steels at a reasonable cost with their innovative approaches and this is likely to change the scenario quickly.
The NanoSteel Company, Inc., USA
Technology: Has developed nanostructured ferrous alloys by devitrification of metallic glass. The alloys are used in the form of thermal spray coatings or weld overlay to tackle the problems of wear, corrosion, erosion etc.
NanoSteel’s patented family of Super Hard Steel® (SHS) alloys offer strength performance up to 10x that of conventional steels. SHS alloys combine the toughness of steel with the hardness of carbides, allowing customers to select the appropriate material to perform in extreme service environments where severe wear and impact are costly problems.
* Erosion resistance is 100% better as reported by independent lab test results
* Abrasion resistance is 250% better (based on ASTM G65-04 testing)
* Bond strength is 12% higher providing a more tenacious bond to substrate
* Coefficient of friction is 25% lower which reduces surface build up of slag, ash and clinker
* Coefficient of thermal expansion is 15% higher which provides for less cracking
QuesTek Innovations LLC, USA
Technology: Has developed computationally designed high strength and environmentally friendly corrosion resistant steels.
Sandvik Materials Technology, Sweden
Technology: Has developed nanostructured ‘Nanoflex’ stainless steels.
JFE Steel Corp., Japan
Technology: Has developed hot rolled, high strength nanosize carbide precipitation strengthened ‘NANOHITEN’ steel for automobile industry.
Kawasaki Steel Corp., Japan
Technology: Has developed non-heat treated ultra-low carbon, Cu precipitation strengthened bainitic steels produced by thermo-mechanical precipitation control process (TPCP).
Kobelco Research Inc., (Kobe Steel), Japan
Technology: Has developed ODS 9Cr martensitic steel (12YWT) for fuel cladding tubes of nuclear reactor.
TWIP (Twinning Induced Plasticity) steel that shows very large elongation of about 70% at 800 to 1,000 MPa has been developed recently. Low density steel has been also proposed which has similar composition and contains Aluminum of about 6%. On the other hand, it has been reported that when a tensile test is carried out for TRIP steel containing 0.4% C at the warm temperature of 150 °C, the equivalent strength and elongation to those of TWIP steel can be obtained. In order to be used as the steel sheet for automobiles, there are still many tasks to be studied, such as adjustment of composition and warm working method. However, it draws attention as the future high-tensile steel for automobiles and processing technology, as same as TWIP steel.
Exxon Mobil Upstream Research Co., U.S.A.
Technology: Has developed high strength pipeline steel for the transportation of natural gas in collaboration with Nippon Steel and Mitsui and Co. It is 20-50% stronger than the currently used pipeline steel. A mile-long section in the TransCanada Pipeline utilizes this nano-steel under -40 degree Celsius temperature conditions.
MMFX Technology Corp., U.S.A.
Technology: Has developed the microcomposite Fe/Cr/Mn/C steels with superior combination of strength-toughness-corrosion properties for concrete members reinforced with high-strength rebars.
Nippon Steel Corp., Japan
Technology: Has developed nanostructured steels for various applications: Fatigue resistant steels containing Cu nano-precipitates for transportation and bridges; High strength steels with resistance to delayed fracture (by hydrogen trapping with nano-size precipitates) for bolts to be used in automobiles and high-rise buildings; High HAZ toughness steel ‘HTUFF’ using nano-size dispersion of oxides and /or sulfides; High strength steel wires for reinforcing automobile tires, galvanized wires for suspension bridges and power cable wires.
Carbon nanotube reinforced aluminum
Carbon Nanotubes Make Aluminum as Hard as Steel But One Third the Weight
The hardness of the composite aluminum and carbon nanotubes is several times greater than that of unalloyed aluminum, tensile strengths comparable to those of steel can be achieved, and the impact strength and thermal conductivity of the lightweight metal can be improved significantly.
Not sure about the new term of covitic aluminum, but CNT reinforced aluminum exists.