Passenger car: steel piston

In every conventional combustion engine, the piston is the element which transfers the energy supplied by the combustion process onto the conrod. In 2014, passenger car pistons made of steel were produced for the first time in series for a diesel application. This piston was designed as a single part. Due to an innovative combination of forging and machining processes, the part can be produced with an internal cooling duct in monoblock design. This renders the joint in the highly loaded combustion chamber unnecessary.


Technical specifications

Application Area Crank drive, engine
Material Heat-treatable steel
Porduction process Forged cooling duct, hot forged, machined
Characteristics Lower engine design height due to reduced part height compared to aluminum, Use of a longer connecting rod possible, Up to 4 % CO2 savings and approx. 50 % lower friction, higher temperature resistance than aluminum, production of the cooling duct geometry by means of a special process combination, innovative forging of the box wall with extremely low wall thicknesses, awarded the Steel Innovation Prize 2015 together with Kolbenschmidt and Daimler for the single-part piston design