New powder for valve seats offers optimal properties at 20% lower cost

Höganäs AB has launched a new metal powder, OB1, which is specially designed to withstand the extreme loads and temperatures that arise in engine cylinders. Utilising the metallurgical expertise within the company, Höganäs has succeeded in creating the first iron-chromium-based powder for this application. This means the powder is 20 per cent less expensive than corresponding alternatives on the market.

In the modern engines used in all types of vehicle, the valve seat is located in the top of the cylinder to reduce friction and wear when the valve is pressed upwards. Around 90 per cent of the world’s engine manufacturers use metal powder for valve seat production. Valve seats are exposed to very high stresses at high temperatures. The trend towards fuel-efficient engines and lean fuels, such as ethanol and gas, also means that requirements are becoming more demanding.

Previously, it has been necessary to alloy iron powder with expensive metals such as molybdenum, tungsten or vanadium in order to achieve the right powder properties for wear and heat resistance. Höganäs has now succeeded in achieving the same properties using chromium as the main alloy and carbide-builder, i.e. the metal that binds the carbon. As a result, the powder is considerably cheaper to produce.

OB1 was recently launched and there has been a good response from customers.
”Many customers already want to test the new material. Using OB1 they will obtain the same high quality as they would from traditional high-speed steel powders, but at a price that is 20 per cent lower. We are the first manufacturer in the world to succeed in achieving sufficiently good properties from an iron-chromium powder, and this gives us a significant competitive advantage. As valve seats are used in nearly all engines, the potential is considerable,” says Owe Mårs, who headed development of OB1.