"It's my job to prepare my best possible case, poke holes in my competitor's case, and convince the customer to use steel for this application." The speaker is J.P.
Automotive Design & Production
, Christopher A. Sawyer
"It's my job to prepare my best possible case, poke holes in my competitor's case, and convince the customer to use steel for this application." The speaker is J.P. McGuire, product applications engineer at U.S. Steel's Product Technology Automotive Group (PTAG) in Troy, MI. He's just run through an explanation of how he convinced one automaker to drop its plans to use an aluminum hood on a new vehicle. It involved showing that the calculations giving steel an 18-lb weight disadvantage were based on worst-case models, creating a detailed proposal based around an optimized design using newer steel grades, and convincing the OEM's purchasing department there would be a substantial cost savings despite the fact that these new steels are more costly on a per-pound basis.*
Although there is an array of new advanced high strength steels (AHSS), some vehicle manufacturers are stuck in an old paradigm. "Many of the models being used are outdated," says Aleksy Konieczny, metalforming specialist at PTAG. "They come from continuous-improvement hell, where the model that has been used for years is updated but not changed. Often, we have to create a new model that better utilizes the characteristics of the new steel grades, and has substantial benefits compared to the steel exemplified in the older model and aluminum." However, the PTAG team produces more than just optimized models. It creates detailed reports that contain the gauges and strengths used throughout the part, to-the-penny cost estimates, as well as a promise that the design can be produced to the customer's quality and durability standards using–as much as possible–the existing machinery and processes. "Not only do we come out significantly lighter than the customer originally expected from steel," says McGuire, "we have a definite cost advantage compared to aluminum." (As a former aluminum company employee, he has unique insight.) And, as often happens, a directive from management to substitute aluminum is met by a detailed analysis of why staying with steel is the better choice.
"We're in a tough battle with aluminum in the automotive sector," says Michael Juddo, PTAG director. Aluminum structures and the technologies necessary to make them have a high-tech, sexy image that steel can't match. For most customers, steel is steel." Thus, familiarity breeds contempt. McGuire posits that it's easier for a "new" material like aluminum to establish new baselines and optimizations paths because it is a relative unknown, and therefore requires more research and development. Steel, on the other hand, is well known and it is difficult to get decision makers in the auto industry to make the financial and monetary commitments necessary to get the most out of the material. "The ULSAB [Ultralight Steel Auto Body] projects woke everyone up to the untapped potential that exists with steel," says Juddo, "and showed what can be done if the effort is expended. These lessons can be applied to production vehicles relatively quickly if we are allowed to work with the OEM's engineering staff from the start of a project."
One major hurdle still stands in the way of this acceptance: Purchasing. "We continue to be treated as a commodity product," says McGuire, "and the proprietary work we do with the OEM's engineering staff is often scheduled to be sent out for bids from competing steel companies." It's a situation aluminum companies rarely face because of their perceived lack of interchangeability. However, by working late hours, getting involved at all levels of the development process, and quickly resolving any problems that arise, the PTAG team has cultivated powerful allies in the engineering ranks who are willing to fight back against the commodity mindset. And that, believe McGuire, Konieczny, and Juddo, is how wars ultimately are won.
*The final steel design shaved 8 lb. off the original estimate, cost significantly less than the aluminum design, and provided an overall cost savings despite the use of more expensive grades of steel by using thinner gauges and eliminating unnecessary supports.