11. Swaging tests

Shrinking is a shaping operation that reduces the initial diameter of the billet. This operation is commonly used to produce the shank for screws and bolts. During this operation, the surface of the billet is highly stressed, and lubrication conditions are particularly important. We have therefore developed this test to classify the coatings and oils used in cold heading. For this test, we use the falling mass described above with the setup shown in figure 16 . This set-up enables us to perform swaging with different reductions depending on the desired severity. We have chosen an example in which stainless steel billets EN 1.4307 (X2CrNi 18-9), or AISI 304L, are passed through this swaging die with the following parameters:

• striking energy 87 J ;

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