A lightweight valve made from a nickel alloy has won first prize in the “Steel in Research and Development” category of the 2003 Steel Innovation Prize. The award-winning valve, made from N06601, containing 60% nickel, was designed by Stuttgart-based Mahle Ventiltrieb to meet the demand for a lightweight, cost-effective valve in combustion engines. The choice of material was based on several, often conflicting, requirements, says project manager Marcus Abele. The material had to be suitable for cold forming and laser beam welding while being able to withstand extreme thermal and mechanical stresses within the corrosive atmosphere of the engine. At average engine speeds, these valves open and close 30 times a second at temperatures up to 950°C. The new valve is 30-50% lighter than conventional valves, reducing the mass that must be moved in the valve actuating mechanism and, in turn, creating less frictional drag within the engine. Less friction and lower weight translates into less fuel consumption, fewer exhaust emissions, a higher allowable engine speed and reduced wear on the engine.
