by Tony Whitney
At first glance, the term “quiet steel” seems like the ultimate oxymoron. After all, bash a couple of pieces of this material together and you’ll get one awful crashing noise. But according to steel industry insiders, the use of Quiet Steel (it’s a registered trade name) is spreading throughout the auto industry as manufacturers strive to create quieter and more refined vehicles.
Refinement and quietness are qualities sought by automakers and customers alike and to find out more about how this is being achieved, I contacted Material Sciences Corporation (MSC), which owns the Quiet Steel trade name. According to MSC, Quiet Steel is a trend that has “flown under the radar” and consumers know very little about its benefits – until they drive a new vehicle built using this technology.
Auto manufacturers use all kinds of technological tricks to keep sound under control in vehicles. Today’s buyers demand a very high level of refinement, even on inexpensive vehicles, and they’re getting it thanks to advancements in bodyshell and powertrain design. Even an entry-level automobile nowadays has a surprising degree of refinement and cruising on the freeway in what used to be a noisy “econobox” is now almost a limo-like experience. Move upmarket into the $35,000-plus bracket and you’ll get a ride once associated with something like a Rolls-Royce or Cadillac.
Refinement-associated technology is constantly changing and Quiet Steel is one of the most recent advancements. Interestingly, MSC points out that this material is basically a Big Three benefit and offshore automakers don’t have it yet. Quiet Steel is probably one of the elements that has contributed so much to the refinement we’re getting these days from General Motors, Ford and DaimlerChrysler vehicles at every price point.
According to MSC, Quiet Steel is “a suite of engineered multilayer composites with various viscoelastic cores among layers of metal.” Think of it as a sandwich of steel and composites created for various applications around the vehicle.
The material is 100% recyclable and according to MSC, offers significant cost reduction opportunities to automakers. Perhaps more importantly, Quiet Steel boasts enhanced noise, vibration and harshness (NVH) performance characteristics. Automakers have been plagued by NVH for years and have fought a constant battle to limit its effect or do away with it altogether. Entire departments at auto manufacturing plants are devoted to dealing with NVH. The new material is designed specifically to meet the sound damping, temperature, stiffness and operating environment needs of its intended component. These components now include parts of the body structure itself, brake parts, powertrain elements and dash panels.
Future applications will include wheelhouses, upper dash cowls, floor panels, package trays, back panels and spare wheel tubs. All these components are susceptible to NVH and can create areas where creaks and rattles may develop – especially as the vehicle ages. There are cost and weight savings too, according to the manufacturer. On one dash panel application, the steel product saved US$9 per vehicle and eliminated six extra pounds in weight. These gains can be multiplied throughout the vehicle, wherever Quiet Steel is utilized. What this means to car buyers is that prices remain stable instead of creeping ever-upward and a lighter vehicle is a more fuel-efficient vehicle. Perhaps unsurprisingly, Quiet Steel is used in other industries (often under different trade names) where benefits related to reducing NVH are sought.
Advanced materials are playing a major part in making your new vehicle that much more fun to drive, while providing comfort and quietness for occupants. Powertrain vibration and noise can resonate through the vehicle if left unchecked, creating unpleasant sounds that penetrate the passenger compartment. With the dash panel application alone, extensive acoustical testing revealed that a substantial reduction in passenger compartment ambient noise could be achieved by using the new material. In many cases, use of the product has eliminated the need to use add-on sound damping material – rubber pads, foams and mastics – on vehicle body panels to reduce noise. Traditionally, vehicles have these materials applied to body panels to deaden unwanted sounds. These add-on treatments, though, can complicate the assembly process and also contaminate paint. Some of them also add more weight than is desirable.
Among vehicles using Quiet Steel to enhance refinement and reduce weight are the Ford F-150 pickup, the Ford Explorer and Jeep Grand Cherokee SUVs and the Chevrolet Cobalt, Pontiac Grand Prix and Buick Allure sedans. All of these vehicles have levels of refinement and quietness that place each of them well to the fore in the segments in which they compete.
Most of us have no idea of the kind of material technology that goes into our vehicles, but these advancements show up in terms of quietness, smoothness and general sophistication – even if we don’t break the bank to buy that new car, minivan, SUV or pickup.