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Trochoidal milling in high-alloyed high-grade steel

When milling wing supports made of highly abrasive austenitic chromenickel steel, milling cutters at ystral gmbh fail after just one component. A solid carbide milling cutter from Gühring ensures the necessary process reliability thanks to its two-fold tool life.

Chipped coatings and high cutting edge wear – when milling wing supports, milling cutters at ystral gmbh quickly reached their limits. “After one component, it was over”, recalls Deputy Production Manager Marco Wissmann. “That’s simply not a reliable process.” This high level of wear is due to the material to be machined: 98 percent of the components manufactured on the state-of-the-art milling machines of this attractive employer in the Markgräflerland region are made of stainless, austenitic chrome-nickel steel.

Gühring milling cutter puts an end to chip nests

Confidently, Oliver Mattes offered ystral to start a trial with a Gühring milling cutter – and had just the right one in mind: the RF 100 5 Speed. “The speed is optimal for this application because it is particularly strong in V4A”, says Oliver Mattes. The solid carbide milling cutter from Gühring ensures extreme metal removal rates even in difficult-to-machine materials with the highest process reliability. With five teeth and a large helix angle of 38°, it is perfect for roughing. The RF 100 5 Speed is also equipped with a 9° back rake angle and offset chip breakers – a major advantage, as Wissmann explains: “When we used tools without chip breakers, chip nests were constantly formed in the machine as chip removal was not possible.” The machine had to be stopped constantly for chip removal. “We save this time now because the much shorter chips are simply flushed out”, says Wissmann happily.

Overcoming all the hurdles

The wing supports with 200 to 230 mm diameter are manufactured as turned parts. The wings, which later serve to disperse the liquids in the tank, are then milled out on the milling machine. This milling operation is carried out in the trochoidal process. The milling cutter moves in an elliptical circular motion and plunges into the material with its entire cutting edge length. This highly dynamic milling technology means that process reliability, tool life and time savings are particularly high – and the RF 100 5 Speed is perfect for this, as it enables up to 10 percent lateral infeed. The contour is then finished with the same tool. The surface quality plays an important role here, as the finished wing supports must have an Ra value of 0.8 mm.

The high-quality SuperA coating of the RF 100 5 Speed breaks off significantly later, so that instead of the previous one component, the Gühring milling cutter can be used to produce two components. “I was also impressed by the fast delivery time”, explains Wissmann. “Whenever we need something, an application technician is always there quickly. This service is simply very good.” Oliver Mattes is also satisfied with the result: “There are always a few hurdles with such a material, but they were all solved in a very reasonable time.”