Progress in Bearing Performance of Advanced Nitrogen Alloyed Stainless Steel, Cronidur 30

Abstract

The bearing rig tests performed in this study, demonstrate superior bearing performance of Cronidur 30 steel over conventional bearing steels. In these tests the L10 life of Cronidur 30 steel as calculated by the DIN/ISO 281 method was 80 times the unfactored L10 life under full lubrication conditions. In boundary lubrication conditions, the Cronidur 30 steel demonstrated the L10 life capability typical of EHD lubrication conditions, whereas the other steels showed a drastically reduced lives. In tests with predamaged races and boundary lubrication conditions, Cronidur 30 demonstrated 8 times the calculated L10 life, whereas the conventional steels exhibited further debit in lives as compared to the boundary lubrication testing whithout predamage. The improved performance of Cronidur 30 steel over conventional bearing steels is attributed to its unique compositional formulation and microstructure that results in provision of balanced properties in the alloy – hardness, toughness and corrosion resistance.

Rolling contact fatigue behaviour of heat resistant bearing steels at high operational temperatures

“…As reported in [2] the rolling contact fatigue behaviour of this material has been proven to be superior at operational temperatures up to 100 8C. This is an antagonism to the results presented in table 2 and fig.…”

“…Cronidur 30 is a newly developed material, in which the carbon is partially replaced by nitrogen to improve the corrosion resistance [1], [2]. For comparison some tests with bearings made from conventional SAE 52100 ± tempered at 220 8C ± have been included.…”

Rolling Contact Fatigue Evaluation of Advanced Bearing Steels with and Without the Oil Anti-Wear Additive Tricresyl Phosphate

“…As described by Forster [17], higher alloy content generally provides a material that resists micro-structural damage, improving fatigue life. Cronidur 30 as described by Tojhan [9], is an exception. The use of nitrogen and the processing of the steel reduce the formation and size of carbides in this material compared to other bearing steels.…”

“…Cronidur 30 is high nitrogen, through hardened stainless steel [9]. The lower carbon percentage replaced by nitrogen leads to improve corrosion resistance and fine uniformly distributed carbides.…”

Surface Hardened Corrosion Resistant Rolling Element Bearings

“…Like the 440C this steel also is used in the through hardened condition at the same hardness level. The corrosion resistance and rolling contact fatigue was proven to be by far superior to the 440C [4,5], but based on the high hardness, material toughness is significantly lower than the core fracture toughness of a carburized part.…”