Hot Stamping Answers the Call for Lightweight, High Strength Steel for the Automotive Industry

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Despite low gas prices, fuel economy is important to today’s consumers. In fact, in a survey by the Consumer Reports National Research Center, 53 percent of American vehicle owners expect their next car to have better fuel economy. Decreasing the weight of a vehicle can substantially improve its fuel economy. In fact, reducing the weight of a vehicle by just 10 percent can improve its fuel economy by 6 to 8 percent, according to the U.S. Department of Energy. Hot stamping is one of the best ways to reduce the weight of high strength steel for the automotive industry.

The greater rigidity and reduced weight provided by hot stamping have led to an increase in the production of hot stamped parts around the world.

Because it takes less energy to accelerate a lightweight object than it does a heavier one, the automotive industry has always focused on ways to improve fuel economy in the vehicles they produce by lightening the overall vehicle weight. Industry professionals refer to the process of reducing overall vehicle weight as “lightweighting.”

Replacing traditional steel and cast iron components with high-strength steel, aluminum alloys, magnesium alloys, polymer composites, and carbon fiber can cut the weight of a vehicle’s chassis and its body in half, which substantially reduces the vehicle’s fuel consumption.

Lightweight materials are especially important for electric, hybrid electric, and plug-in hybrid electric vehicles, as the lightweight materials offset the weight of batteries, electric motors, and other weighty components of the power system. Weight reduction also improves efficiency and boosts the vehicles’ all-electric range. The use of lightweight structural materials also allows vehicles to carry additional safety devices, integrated electronic systems, and advanced emission control systems without increasing the vehicle’s overall weight.

Hot Stamping

High strength steel (HSS) hot stamping is a manufacturing technology that combines the traditional hot forging with cold stamping technology. This mode of production involves the stamping of steel at high temperatures followed by forming and quenching in dies.

The Swedish company Plannja developed and patented hot stamping in 1977, according to ASM International. In 1984, Saab Automobile AB became the first company to use hot stamping in the automotive industry when they used a hardened boron steel component for the Saab 9000.

Vehicle manufacturers now use hot stamping to produce front bumpers, rocker panels, side impact beams, the inner B pillar that forms the windows and doors, roof rails, sub-plates and other parts.

Hot stamping is the process by which steel blanks are heated, pressed into shape, and rapidly cooled. The process allows manufacturers to form stronger, lighter part more efficiently than through other methods, such as cold stamping. Hot stamping produces a thinner, lighter piece of steel that effectively replaces a heavier, thicker part while still increasing the relative strength of the frame. This allows automotive manufacturers to lower the overall weight of the vehicles and improve fuel efficiency.

The hot stamping process features heating a blank to its austenitization temperature, which is hot enough to change the crystal structure of the steel from ferrite to austenite. Austenite steels are generally more durable corrosion-resistant than are ferrite steels.

Cold stamping is often associated with springback, which occurs when the metal tries to return to its original shape after being released from its forming tool. Hot stamping reduces springback so that all parts retain their intended shape. Minimizing springback also gives steel better crash properties.

Using the right furnace is essential to hot stamping lightweight, high strength steel for the automotive industry. LindbergMPH hot stamping furnaces use a direct method, non-isothermal forming process that transforms flat sheets of steel into the high-strength, lightweight thin sheets that are used to manufacture automobile components, including bumpers, body pillars, framing, side impact beams, roof rails and other parts that vehicle manufacturers need to improve fuel economy. For more information on Lindberg/MPH hot stamping furnaces click here and make sure to follow us on social media.