Considering the increasing use of plastics and variety of lighter and alternative raw materials, is the use of steel in the automobile industry on the decline? According to Nico Langerak from Tata Steel, there continues to be a future for steel in the car industry. “Steel is unbeatable when it comes to recyclability, crash resistance and CO2 environmental performance during the production process.”
Tekst Nico Langerak
Steel is steel, many might say. But nothing could be further from the truth. No two types of steel are the same, explains Nico Langerak, Department Manager for Application & Engineering Research & Development at Tata Steel. “The types of steel used in cars and engines nowadays did not even exist 20 years ago.” He makes a comparison with the Daf from 1970. “The strength level of the steel used back then for this uber-Dutch icon was 200 megapascal. Modern cars are made of high-strength steel of up to 2,000 megapascal, i.e. ten times as strong. This means that if you were to use today’s steel to build that same Daf from 1970, the car would be half as heavy and much more crash-resistant.”
Shredder scrap from steel production
Tata Steel produces 28 million tonnes of steel each year worldwide, of which 18 million tonnes are produced in Europe and seven million tonnes at the factory in IJmuiden. Around one-fifth of European production is intended for automobile manufacturers. Another reason for the production of those seven million tonnes of steel in our country is that the company uses around one-and-a-half million tonnes of scrap, some of which originates from shredder material from Dutch end-of-life vehicles.
According to Langerak, the development of steel in recent decades, and especially in recent years, has gained momentum. “Weight reduction plays an important role in this, although the same can be said of the continuously stricter Euro NCAP crash test requirements. To achieve five stars as a car manufacturer, the use of high-strength steel is an absolute must.”
Various qualities of steel
But supplying high-strength steel is only one aspect of many. It is also important for car manufacturers that the steel is easy to work with. The average car contains 70 to 80 different types of steel that have undergone a specific rolling process or other type of finishing treatment. Langerak emphasises that, to meet the specific preferences of car manufacturers, Tata Steel works together closely with manufacturers and their suppliers of pressing tools and installations from the design phase to ensure an optimal production process and maximum utilisation of steel qualities.
That does not alter the fact that automobile manufacturers are increasingly using alternative types of materials to some degree. These include the ‘carbon light bodies’ of the BMW i3 and the 100% aluminium car bodies of the Audi A8.
“Costly Carbon Fiber-Reinforced Plastics (CFRP) are only really found in the very highest segments and such exclusive car brands as Lamborghini,” says Langerak. “Ultralight yet extremely expensive materials are used to achieve the weight reduction needed for above-average sports performance.”
He also says that aluminium parts are particularly in vogue nowadays in the premium segments. “The Audi A8 was the first fully aluminium production car. I say was because the brand decided to use 2,000 megapascal high-strength steel in the later models due to better crash properties. It is a highly dynamic field, but I don’t believe in a breakthrough of carbon, aluminium or reinforced composites at the expense of high-strength steel in the future. On the contrary, the possibilities of steel are far from fully developed. I expect that today’s cars could be at least one-fourth lighter with the use of the very newest types of steel.”
Better environmental performance of steel
Steel also offers several other environmental and sustainability related benefits, apart from the affordable purchase price, that translate into a significant competitive advantage compared to the earlier mentioned alternative materials. Langerak continues, “Firstly, steel is fully recyclable. Carbon can be recycled into a few simple roadside posts at most. Aluminium can be recycled, but is highly alloyed, which means you cannot combine different types of aluminium. Not only that, but steel also scores more highly in terms of CO2 emissions during the production process. “In addition,” adds spokesman Robert Moens from Tata Steel, “we’ve succeeded in reducing the amount of energy needed to create one tonne of steel by 31 percent over the past 25 years.”
As far as Langerak is concerned, there is still a very long road ahead. Moens mentions the pioneering HIsarna project, an initiative of Tata Steel. The goal is to produce liquid crude iron in a different manner that entails skipping an entire production step (the pretreatment of iron ore and coal). Moens continues, “If this project is successful, it will be possible in the future to achieve a CO2 emissions reduction of at least 20 percent. This once again proves that steel is a highly competitive material and will continue to be so. In addition, the already lower quantity of CO2 released with the HIsarna technology is so pure that it can easily be trapped and stored.”
Life Cycle Assessment
Langerak believes that today’s car manufacturers are being restricted far too much by policy in their choice of materials due to the amount of CO2 released. He calls this a short-sighted policy. To objectively assess the environmental performance and advantages of a specific material, you need to examine the entire life cycle of the car. “How much CO2 is released during production, how much during usage and what about recyclability? You need clear answers to these questions in order to properly assess the ecological footprint of a specific type of material.”
Shift in emission standards
Langerak shows a number of tables and studies that clearly show that carbon fibres and magnesium actually score very low in terms of life cycle because the CO2 emissions released during production are at a very high level. The production of a single car from magnesium requires 20,000 kilos of CO2. The use of steel cuts this amount in half. He believes you can safely say that the ‘purer’ the car, the longer the life cycle of the production component. “Of course,” adds Langerak, “it is also important how this is approached by European lawmakers.” European legislation is currently still based entirely on vehicle emissions. For the year 2020, the European Commission has defined average CO2 emissions of 95 grams per kilometre. I expect a shift to take place after that date and that Brussels will base the standards on a Life Cycle Assessment, which will then be the focus of the automobile industry.”
Steel is high-tech
Langerak is certain that steel will also remain the standard in the future. The demand for high-strength steel will triple between now and the year 2030. Admittedly, the demand for conventional steel will be half of what it is today, but Langerak does not believe that this will result in a substantial increase in the demand for competitive types of materials. The use of aluminium alone is expected to increase sixfold by the year 2030. The consumption of magnesium, composites (carbon fibres) and other plastics will continue to be on a considerably low level in 2030.
The only development that could change this is the advent of self-driving cars, jokes Langerak. “If everyone were to have a self-driving car in the future, they would no longer crash into one another. So there would be no need to make cars more crash-resistant. But he does not believe that this is the way of the future. Steel is here to stay. “In the past, steel was a commodity product. Today, it’s high-tech!”