The steel industry is constantly innovating to develop new solutions that satisfy customers in a range of industries, the automotive industry included. Stricter fuel-economy and safety regulations challenge automakers to cut weight yet improve safety—which in turn challenges materials suppliers to come up with the technologies that enable such seemingly contradictory goals to be met. ArcelorMittal is among the companies pushing the boundaries of materials advancements. For the NAFTA region, the supplier expects orders for its advanced high-strength steels (AHSS), including press-hardenable steels, to rise from 20% of total automotive steel orders today to 35% in 2019. At any one time, up to 80 new steel grades are under development at ArcelorMittal. The person responsible for these advanced-development activities is Greg Ludkovsky, Vice President of Global R&D. Ludkovsky, who oversees 1300 full-time researchers at 11 research centers around the world, spoke with Automotive Engineering Associate Editor Ryan Gehm this fall at the AM/NS Calvert plant in Alabama, which the company touts as “the world’s most advanced steel finishing facility.”
Could you talk about the significance of this Calvert plant and how it serves your purposes as a researcher?
Well, a lot of properties can be created in the hot strip mill based on the thermo-mechanical profile of what steel undergoes as it travels from the furnace all the way to the coiler. The greater flexibility you have in terms of reduction, in terms of temperature distribution, in terms of cooling rates, in terms of ability to create variable profiles in cooling, the more your ability to create unique properties. This mill is state of the art in respect to what you can do there. It’s a very powerful mill, so you can take very heavy reductions—the heavier the reduction, the more you refine the microstructure, and the more you refine the microstructure, the better the hot roll properties. [The mill also] has a very long and very flexible cooling system on the run-out table—the distance between the last finishing stand of the cold mill, the hot strip mill, and the coiler. So when the steel travels in this distance, it changes phases, it changes grain size, [and] many other phenomena are taking place. You can have precipitation of certain elements that further strengthen the material. The fact that you have this unique flexibility allows you to do much more complex thermo-mechanical treatment, and therefore achieve a great deal of property improvement, for both the hot-rolled product and then ultimately cascading to the final product. That is the key advantage of this mill…For me as a researcher, the crown jewel is the hot strip mill.
Your R&D department serves many different markets. Which one’s at the forefront of steel technology and provides the most challenges?
Automotive is definitely the most challenging. As long as safety and ecology remain in focus, automotive will be a continuous driver of innovation. But the market which is evolving and I believe will see a lot of interesting new developments is the energy market, because the sources of sweet oil [low level of sulfur] are getting depleted, so more and more we are dealing with sour oils. And more and more oil is coming from areas of extreme temperature, so the requirements in terms of performance of the material are increasing substantially. [In addition], we will be talking about carrying huge amounts of gases, for example, CO2, shale gas, compressed gases, so there’s new developments in…energy products. But I would say in terms of commitment, where the market’s at right now, [the one that] gets the highest level of attention, it would be automotive.
What is the connection between your electrical engineering R&D and its application in electric vehicles?
The future of electric vehicles will be based on many constants…You have a battery—hopefully it will shrink in size because today it’s very heavy—and then you can have either one central motor [or] four motors, one on every wheel. All the electricity that the battery will supply will be spent on two things: the positive one is propulsion—you’ll be actually moving your vehicle; the other one is waste, electrical losses, manifested in the heat that will be generated in all of these motors. And it’s not productive, it’s pure waste…So what you do is develop very unique steels that go into the motors that decrease the amount of heat losses. We’re in the forefront of these developments as well. And by the way, because these motors are very heavy, we can provide the product which gives what they require in terms of torque, and at the same time, very low losses. We are achieving both things: we’re decreasing weight [and] we are letting—for the same battery with high efficient motors—the car run longer between charges. This is for purely electrical vehicles and for hybrids, so we’re developing the steels for manufacturers in both [segments].
How important are co-engineering projects to product development?
I cannot talk about specific customers, but we are involved with co-engineering projects throughout the world, very actively. Co-engineering is our forte, it’s our unique distinguishing [capability]. For example, development with Honda [on a ‘stiffener ring’ door frame for the 2014 Acura MDX, later used on the 2015 TLX] that won innovation of the year awards. [Editor’s note: read more at http://articles.sae.org/12225/ or view video at http://youtu.be/XOSTJzDD-FU.]
Blake Zuidema, Director of Automotive Product Applications, said that ArcelorMittal will have solutions should Ford decide to come back to steel for the F-150. What are those solutions?
In essence what Blake demonstrated in his presentation [on the S-in-motion steel pickup study] is the fact that we were able to take 174 kg (384 lb) out of a current  pickup truck [using currently available AHSSs and press-hardenable steel grades such as Usibor 1500 and Ductibor 500]; we reduced by 23% the weight of the cab, box, tailgate, frame, etc., and with new steels [that are in the final stages of development] it’ll be 26%. Our calculations show that with this combination of our new steels and our design solution, it’s possible to reach 2025 targets.
With third-generation steels, and even beyond, how much lighter and stronger can automotive structures become?
The first stage of third-generation steel will allow us to lighten the components by 10%, and the next stage will allow us to lighten by 20%. It’s important additional weight savings compared to today’s advanced high-strength steels. So we’re going to replace maybe a 980- or 1000-MPa product with 1500, a 590 product with 1100 MPa, [and] 780 will be replaced with around 1200-MPa products. And this will depend on which [stage], level 1 or level 2.
As steel continues to enable lighter and stronger structures, does that open up more applications to you, such as the aerospace industry?
We have not done much, but I’m thinking that it’s probably about time we started looking at that (laughs)…I’ve been in this business for a long time, but I probably have more fun now than in any preceding year of my life. Now it’s like a kid in a toy store. There are so many things that we do—we dream and then we implement. And we very rarely fail…when we set our [focus] on doing something.Continue reading »