Betriebsanleitungen nach der EG-Richtlinie „Maschinen”︁

Europe takes shape. National interests must give way to european interests. Laws, standards and other rules of technic must be reduced to a common denominator, the european standard. The EG-Rules for machines has already been integrated into some national rules. At the beginning of 1995 it shall replace completely the national rules. At the latest on this date the technical documentation has to be adapted.     

Über adiabatic shearbands und die Entstehung der „Steilen Weißen Bänder”︁ in Wälzlagern

About adiabatic shear bands and the generation of “high‐angle white bands” in roller bearings During the rolling motion of roller components structural changes are generated by over‐elastic distressing below the bearing face. Micro‐ and macro‐plastic distortions of the microstructure due to the three‐axial distressing accompany the process of rolling contact fatigue with the start from the first load cycle. They determine the life‐duration of the roller component. Further structural changes in ball bearings besides the plastic deformations are the so called “butterflies” and the so called low‐ and high‐angle “white bands”. The “white bands” you only can detect later, after an extended number of rolling actions. They are inclined to average circumferential angles at ≈ 30 ° respectively ≈ 80 °. Butterflies and white bands develop obviously due to a two‐axial material stressing. An influence on the life duration is not proved. The structure and the mechanism of their generation are under discussion. There exist phenomena of the microstructure which are similar to the white bands, the so called adiabatic shear bands. These generate after a local macro‐shear process of the microstructure, caused by a single, rapid shock‐shear stressing. Flash‐temperatures near the melting point generate in the shear zone of martensitic hardened materials the formations of new hardened zones; these microstructures cannot be etched too. The paper contributes to the question, if there exists a stress‐constellation which causes the adiabatic formation of butterflies and of white bands during the steady and long during process of plastic deformation. If one considers the latest knowledge about rolling contact fatigue and stressing by EHD (elasto‐hydro‐dynamic) flow, he can come to the conclusion, that at least the “high‐angle white bands” are adiabatic shear bands.