Nissan introduces new 1.2 GPa ultra high tensile strength steel with high formability; reduction in body weight of up to 15 kg
05 October 2011
Nissan Motor Co., Ltd., in collaboration with Nippon Steel Corporation and Kobe Steel, Ltd., has developed Ultra High Tensile Strength Steel rated at 1.2 gigapascals (GPa). From 2013, this new, highly formable steel will be produced as steel plates for use in cold pressing structural body parts. To be deployed globally in models across the Nissan lineup, it will reduce vehicle body weight by up to 15 kilograms (33 pounds).
The new Ultra High Tensile Strength Steel will be used for center pillar reinforcements, front and side roof rails and other key structural components. By exceeding the structural body performance of previous materials with less thickness, the new steel will contribute to increased dynamic performance and fuel economy.
The new material will also contribute to lower total costs including that of manufacturing, as superior cold-pressing formability supports mass production.
Nissan says that the new material overcomes significant obstacles. Until now, high tensile strength steel involved a critical trade-off: increased strength came with increased rigidity and a consequent reduction in press formability. Maintaining quality in spot-welding has also been an ongoing challenge. Traditionally, only high tensile steel rated up to 980 megapascals (MPa) can be used in cold pressing structural body parts, requiring complex press work, the company said.
The new 1.2 GPa steel, combined with Nissan-developed advances in welding methodology, overcomes both obstacles.
Development of the new material was realized by a breakthrough in the ability to control its structural formation at the sub-micron level in combining hard and soft layers to achieve both strength and formability.
Once the new material was developed, extensive experimentation was required to develop an optimal spot-welding methodology. This has been achieved with a proprietary process that involves careful optimization of welding pressure, current volume and power distribution.
By adopting the new material to various parts of the vehicle, the new 1.2GPa Ultra High Tensile Strength Steel with High Formability will contribute significantly to overall vehicle weight savings without adding the extra cost required by other lightweight materials, such as aluminum, Nissan said.
The auto industry should focus on using aluminum instead of iron/steel as the CO2 emissions from iron production are not sustainable. Iron is predominantly made from burning coal or natural gas in combination with iron ore whereas aluminum is made by using electricity that can be CO2 neutral. For instance, all the aluminum produced in Iceland is made by using cheap electricity made by geothermal power plants.
To promote the transition to materials with less CO2 impact legislation is needed that require producers of all commodities to document and label their products with the CO2 emissions involved in producing the product. That will enable consumers who care to pick products that are made with less CO2 emissions. It could also provide the basis for a CO2 dependent tax collection system. That would be especially attractive for Europe as it would make Chinese and US produced commodities more expense because they are produced with more CO2 emissions and therefore easier to compete with from the point of view of European companies.
The point is that in order to combat pollution it needs to be priced or nobody will care about reducing it.
Posted by: Account Deleted | 05 October 2011 at 03:03 AM
33 pounds? Is that all?
Posted by: JMartin | 05 October 2011 at 07:45 AM
Yes, aluminium and composites could do much better but at a current higher cost. A mix of all three may be an acceptable compromise to lower vehicles weight by as much as 30% to 50%.
Posted by: HarveyD | 05 October 2011 at 08:17 AM
Steel produced in Japan may be made as you suggest, but that is NOT TRUE in America. Better than 90% of US steel is manufactured from recycled scrap steel in enlarged, high quality, tool-steel electric arc furnaces.
For an enviro, this is a perfect example of true sustainability, as well as true economic progress. Unlike the phony enviro nonsense of Solyndra, EverGreen, Nrel, and a long list of politically connected payoffs to cronies, that had zero probability of lasting beyond the last subsidy.
Making steel in this manner, in so-called mini-Mills, as America now does, uses much less energy remelting 90% steel scrap as "ore", instead of from 2-3% iron ore.
American Steel is now the most profitable and envy of the world, with which third world countries can't compete, since they don't have two centuries of scrap steel to draw upon as "ore".
Posted by: ExDemo | 05 October 2011 at 12:06 PM
I like Ice Land's method of exporting electricity as refined aluminumn, but I've heard the bauxite ore is imported to Ice Land from as far away as New Zealand. There is some carbon cost to that.
Posted by: HealthyBreeze | 05 October 2011 at 04:17 PM
Most of the bauxite that goes to Iceland comes from Jamaica iirc.
Let's not forget Flash 4130 bainite steel.
FWIW, one has to weigh the cost of weight reduction with the benefit of reducing costly components such as batteries (assuming we are moving to a PHEV/EV centric economy).
Posted by: GreenPlease | 05 October 2011 at 07:36 PM
They need to concentrate in improving the visibility in modern cars.. make those A, B, and C pillars out of slimmer steels please.
Posted by: Herm | 06 October 2011 at 09:20 AM
I am concerned that thinner sections of higher strength steel will be more vulnerable to corrosion than thicker sections of lesser-strength steel. If you lose even a hundredth of a millimeter to corrosion, you have weakened a component a lot more if you start with a very thin section, than if you start with a thicker section.
Posted by: Alex Kovnat | 06 October 2011 at 02:03 PM
Ex-Demos...I don't know where you got your stats but USA went from 37% of the world steel production 1930 to about 5% in 2010. By 2020, the forecast are for something between 2% and 3%.
In its dying days, the local steel industry is using more and more scrap. That is a good move and a way to get higher subsidies.
Posted by: HarveyD | 09 October 2011 at 10:59 AM
Don't just count the old steel companies like US Steel, or look at raw steel production from ore. You need to count the mini-Mills too, who remelt old steel scrap and make most of the US steel today.
Posted by: ExDemo | 09 October 2011 at 04:01 PM