The first two commercially available grades in the family were Hybrid Steel 60 and 55, designed to achive 60 and 55 HRC hardness, respectively. The first is a unique grade of bearing steel for applications where added strength is needed at elevated temperatures. The second grade suits an array of engineering steel needs with the addition to corrosion resistance.
We have now extended the family with Hybrid 50 that offers exciting possibilities for component manufacturers to dispense the need for quenched and tempered steel. This is because they can forge their component to near net shape, machine it in as-cooled (soft) condition and then achieve the final hardness they need with simple aging treatment.
Our team decided to develop Hybrid 50 after detailed discussions with manufacturers of critical high-strength components, especially in the automotive industry. They were seeking an alternative to the quenched and tempered steels they currently use. The reason was that they wanted to address some of the drawbacks, such as renewed surface oxidization, which can prevent cleaning of some cavities in components or that the heat treatment has to be performed in a protective atmosphere, which is expensive. Distortion can also be issue, which means that machining allowances have to be increased.
We knew that Hybrid Steel 55 was not the complete answer, because in components such as suspension arms the resulting hardness would be too high, combined with low toughness. Furthermore, following hot forging and cooling, the steel would be hard to machine. That is why we developed Hybrid Steel 50 – designed around a hardness of 50 HRC. The main difference in the composition of the steel is a reduced level of carbon and vanadium.
A main advantage of Hybrid Steel 50 is that it is very suitable for near net shape forging. Primarily because it does not need to be quenched to achieve a martensitic structure after hot forging. This avoids the need for an environmentally harmful quenchant. It also minimizes component distortion, enabling a reduction in the need for final machining processes. The decrease in scrap and need for less handling increases productivity and saves machining tool costs.
