The coveted Steel Innovation Award 2015 category, „products made of steel“, has been awarded to Daimler AG. The prestigious award of the German Steel Federation is awarded every three years and honors this year the newly developed steel pistons for passenger car diesel engines with a significant CO2 savings and high performance potential.

Two to four percent lower fuel consumption and CO2 emissions – this is the overall noticeable balance of Mercedes-Benz passenger car diesel engines, the first ever engines in the word equipped with innovative steel pistons in conjunction with lightweight aluminium housings. The consumption advantages are important and even more pronounced for the everyday low and medium engine speed ranges. In September 2014, the new high-tech steel piston celebrated its world premiere in a production car; the V6 diesel engine of the Mercedes-Benz E 350 BlueTEC.
At first glance, the combination of aluminium housing and steel pistons seems problematic because steel expands less when heated than aluminium; it conducts heat more poorly and is heavier. Therefore, so far Alu-Pistons have been used. However, the Stuttgart engine designers minted these apparent disadvantages into benefits. For example, the low expansion of steel through rising operating temperatures ensures a growing interplay between piston and aluminium housing, and reduces friction by 40 to 50 percent. The higher strength of steels allows, at the same time, a very compact designed, lightweight pistons, for even extra strength reserves. Finally, the lower thermal conductivity of steel leads to increased component temperatures, thus improving the thermodynamic efficiency with higher ignition performance and reduced burn time.

The steel pistons previously used, however, were poorly suited for a combination with engine housings made of aluminium. Rather, Mercedes-Benz had to completely redesign the piston. The modern designed steel pistons used for the first time in the V6 diesel in the E 350 BlueTEC, come at series production in the aluminium crankcase with NANOSLIDE cylinder liner coating. These are high-tech versions, which are forged from high-grade strong steel. This means a great challenge for the piston supplier, because the new, ultra-strength steels are also demanding in terms of production.

The Steel Innovation Prize is awarded every three years by the German Steel Federation and is one of the most important innovation awards in Germany. The award was presented last night by the patroness of the Steel Innovation Prize, Prof. Dr. Johanna Wanka, Minister of Education and Research, as part of the Berlin Steel Dialogue. Dr. Torsten Eder, Vice-President of the Competence Center engines, as a representative for Daimler AG, personally received the prize. Daimler development partner KS Kolbenschmidt GmbH and its participating partner, the Hirschvogel Holding GmbH, also received awards for the innovation. With 578 applications by architects and engineers, technicians and designers as well as designers, researchers and inventors, the Steel Innovation Award one of the leading competitions of its kind in Germany.

As early as October 2014, the innovative PC Diesel steel piston had been awarded with the MATERIALICA Design + Technology „Best of Award“ in the category „CO2 efficiency“. This price is awarded for material applications and surfaces in product and technology developments across all industries.

Source: Daimler AG