The basis for high-fatigue performance in high-hardness steel originates in precise inclusion engineering. In addition, recent research shows that by changing the alloying strategy, an increase in the bending fatigue limit can be achieved similar to that of adding another shot-peening process. This paper describes the potential of clean steel for new approaches in transmission gearbox manufacturing and possibilities to meet the future demands for smaller, lighter and managing higher torque. An important factor is the bending fatigue performance of gear teeth where increasing fatigue strength is required. The paper discusses how shot peening might be eliminated in high-cleanliness, as-carburized steel components using an alternative composition. The full benefit of this new steel design can be obtained by using a highquality steel with a decreased number of critically sized inclusions in the loaded volume. To address potential machining issues of clean steels, the paper also deals with the production process, including quantitative machining trials and the importance of tooling selection. The study is focused on the production of gears - primarily with turning and hobbing. Initial results show how these clean steels can be machined in full scale production in standard conditions with equal or better efficiency and cost.
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