STEEL VS AL: Steel still trumps aluminium for cost-efficient, sustainable carmaking

Steel remains a key material and a worthy competitor for alternative materials in an age of constantly evolving technology in car manufacturing, industry participants have said.

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The cost efficiency, recyclability, safety advantages and mass-reducing possibilities of steel have earned it strong backing from steelmakers, car manufacturers and industry associations.

“Steel is constantly improving and changing,” a spokesman for World AutoSteel, the international trade body for the automotive iron and steel sector, told Steel First at the end of 2013.

“Its inherent characteristics allow us to engineer new advanced high-strength steels that have the properties needed to achieve our customers’ goals, yet are still affordable and 100% recyclable,” he said.

It is by no means a “dormant” material, World AutoSteel added.

Now more than ever, steel was the raw material “of choice” for components that are lightweight and readably formable while offering excellent strength and durability, German steel major ThyssenKrupp told Steel First.

Honda’s luxury car brand Acura recently showcased steel as the preferred raw material for carmaking with its “hot stamp dooring” technology.

The structure around the doors of the new 2014-model MDX Acura is made of “super-strong, high-strength steel”, an Acura spokesman said, adding that the company was the “first and only [carmaker] to apply hot stamping in this way”.

Steel here to stay
Automotive manufacturers have been looking for ways to replace “incumbent” steel materials for the past 100 years, according to World AutoSteel. However, it remained adamant in its claims that steel was not being replaced by other materials, but by more highly developed steel goods.

“In most cases, the steel of the day is being replaced with the next generation of steel products,” a World AutoSteel spokesman said. “The steel industry sees that the only way to remain relevant to the automotive industry is to develop these new products that will make the previous generation of steel obsolete.”

It will “continue to do so”, he said. “Steel is still, and always will be, up to the job.”

Cost efficiency
Steel still trumps other materials used in car making by providing “lower-cost” solutions, according to the world’s largest steelmaker, ArcelorMittal.

In comparison, aluminium costs as much as 60% more when used in automotive production, World AutoSteel told Steel First.

“If a product is not affordable, then its sustainability as a solution is questionable,” the association added.

The USA’s Massachusetts Institute of Technology (MIT) further broke down the costs of steel use compared with aluminium.

In raw materials costs, aluminium is about three times more expensive than steel, while in terms of conversion costs it is about twice as expensive, MIT said. And in assembly costs, aluminium was 20-30% more expensive than steel.

One Belgian analyst said that a switch to aluminium in car manufacturing would trigger a “negative domino” effect.

“If all automotive producers that currently use steel in car production switched to aluminium, demand for aluminium would increase dramatically, making such a change economically unviable for carmakers,” the analyst said.

Cutting weight
Advanced high-strength steels can offer more benefits to car makers by helping to make vehicles lighter, several steelmakers have argued.

ArcelorMittal told Steel First that its efforts to create lightweight steels have progressed and that it can deliver vehicle “light-weighting” benefits “at a lower cost to the consumer and with fewer environmental drawbacks than alternative solutions such as aluminium, magnesium or carbon fibre”.

Steel, one specialist added, is 100% recyclable and, therefore, “environment-friendly”. This was “as opposed to aluminium, which is not as green a material”, he said.

In 2013, German carmaker Volkswagen replaced most of its aluminium parts with new ultra-light, high-strength steel products.

“As nearly one-quarter of fuel consumption is attributable to a vehicle’s weight, Volkswagen uses innovative lightweight steel designs in order to reduce [the car’s mass],” the company told Steel First in April 2014.

“The harder the steel, the thinner and thus lighter the steel parts can be,” Volkswagen explained.

The car manufacturer, which has production sites in more than 18 countries, recently announced large investments in new production facilities and technology systems.

“Volkswagen has acquired special know-how in [lightweight steel design] and has made significant investments in production facilities,” the company said, adding that its innovative lightweight steel designs are heavily showcased in the Golf 7 model.

In 2013, the company said that it would invest €9.8 billion ($13.6 billion) in China over a three-year period, and in March 2014 said that it would invest a total of €5 billion ($6.9 billion) in Brazil by 2018.

In conclusion, steelmakers collectively report that a full life-cycle analysis favours steel over other materials in automotive manufacture.

“Awareness is increasing among carmakers and regulators,” ArcelorMittal added.