The material properties of 100Cr6 steel under hydrogen influence are being investigated with the aim of a better understanding of early failures in rolling bearings. For this purpose, tensile test with hydrogen charged samples were carried out with a specified strain rate. A significant reduction in tensile strength compared to non-charged samples was measured. The test was repeated with different hydrogen contents of the samples, adjusted by the charging pressure. Even with low hydrogen contents in the samples, a significant reduction in tensile strength was demonstrated. The analysis of the fracture surfaces shows clear differences in the fracture behaviour of the hydrogen-charged samples and the untreated samples. In the loaded samples, brittle fractures with intercrystalline cracks occur which can be clearly attributed to hydrogen embrittlement. To understand the mechanisms, binding energies were measured on pressure-loaded samples.

The findings regarding the influence of hydrogen on the tensile strength of bearing steel 100Cr6 can help to explain the occurrence of premature cracks at a very early stage of rolling contact fatigue. The load capacity of the material is greatly reduced by the influence of hydrogen if the load remains constant due to overrolling. This results in an unfavourable ratio of applied load to load capacity, which leads to failure of the rolling bearings. The objective is to integrate these results into a service life model for rolling bearings influenced by hydrogen.