Quadworx® roughs Pelton double buckets

The water jet hits the specially shaped double buckets (blades) of the turbine impeller, where it is deflected and slowed down. The kinetic energy of the water is transferred. The water pressure drives the turbine. Electricity is produced. The split bucket ensures that the jet force is evenly distributed and back losses are minimized.

To fulfill this function, Pelton double buckets must be corrosion-resistant and extremely strong. Ideal materials are tough, extremely wear-resistant, and inexpensive, while also being lightweight.

Tool steel 1.2312 is sulphur-alloyed. This improves its machinability compared to other tool steels. With hardnesses of 280 to 320 HB in the delivery condition, increased tool wear is to be expected during machining. However, the steel can be tempered and achieves hardnesses of approx. 50 HRC with heat treatment. This medium strength is suitable for low to medium loads. Stainless steel, hardened steels or titanium are the better material choices for extreme conditions.

The Quadworx® indexable insert milling cutter was used in this practical example. To reduce thermal loads, the high feed milling cutter was selected as the tool for high-speed cutting (HSC). Quadworx® effortlessly roughs a Pelton double bucket made of tool steel 1.2312 with a feed rate of 5800 mm/min and a cutting depth of 0.8 mm.