*Article* **Investigations on Tailored forming of AISI 52100Rolling Bearing Raceway**

**Timm Coors 1,\*, Maximilian Mildebrath 2, Christoph Büdenbender 3, Felix Saure 1, Mohamad Yusuf Faqiri 2, Christoph Kahra 2, Vannila Prasanthan 4, Anna Chugreeva 3, Tim Matthias 3, Laura Budde 5, Florian Pape 1, Florian Nürnberger 2, Thomas Hassel 2, Jörg Hermsdorf 5, Ludger Overmeyer 5, Bernd Breidenstein 4, Berend Denkena 4, Bernd-Arno Behrens 3, Hans Jürgen Maier 2 and Gerhard Poll 1**


Received: 31 August 2020; Accepted: 10 October 2020; Published: 13 October 2020

**Abstract:** Hybrid cylindrical roller thrust bearing washers of type 81212 were manufactured by tailored forming. An AISI 1022M base material, featuring a su fficient strength for structural loads, was cladded with the bearing steel AISI 52100 by plasma transferred arc welding (PTA). Though AISI 52100 is generally regarded as non-weldable, it could be applied as a cladding material by adjusting PTA parameters. The cladded parts were investigated after each individual process step and subsequently tested under rolling contact load. Welding defects that could not be completely eliminated by the subsequent hot forming were characterized by means of scanning acoustic microscopy and micrographs. Below the surface, pores with a typical size of ten μm were found to a depth of about 0.45 mm. In the material transition zone and between individual weld seams, larger voids were observed. Grinding of the surface after heat treatment caused compressive residual stresses near the surface with a relatively small depth. Fatigue tests were carried out on an FE8 test rig. Eighty-two percent of the calculated rating life for conventional bearings was achieved. A high failure slope of the Weibull regression was determined. A relationship between the weld defects and the fatigue behavior is likely.

**Keywords:** tailored forming; hybrid bearing; AISI 52100; plasma transferred arc welding; residual stress; scanning acoustic microscopy; bearing fatigue life
