Shattered rim and shelling of high-speed railway wheels in the very-high-cycle fatigue regime under rolling contact loading

Abstract

Due to the improvement of the wear property, rolling contact fatigue including shattered rim and shelling are the main failure causes of the high-speed railway wheels. In this paper, shattered rim and shelling occurred on the service wheels of the China Railway High-speed (CRH) trains were systematically investigated. The recorded data of the last ten years CRH operation indicated that all shattered rims and shelling were detected with serving > 10 6 km (corresponding to the fatigue life 10 7 -10 9 cycles) which is very-high-cycle fatigue (VHCF). The crack initiation region of shattered rim located at the depth of 10-25 mm from the tread, while that of shelling located at the depth < 10 mm from the tread. The VHCF features under rolling contact loading were observed on the opening crack surfaces, i.e., similar VHCF features in uniaxial loading including the defect, fish-eye, and crack propagation region and unique VHCF features of the three dimensional crack surface feature, beach bands uniformly distributed in the crack propagation region, absence of fine granular area (FGA). The VHCF model considering the stress distribution, defect size and hardness were applied to discuss the failure mechanism of the shattered rim and shelling. effects of material defects and the contact shear stress profile with a maximum shear stress below surface are responsible for the https://doi.

Very high cycle fatigue life and critical defect size: Modeling of statistical size effects

“…The theoretical results reported in the present paper can be usefully applied to predict the VHCF life of components, in‐service conditions. The models can account for the actual large size of components 5–8,10 and for the actual geometry and loading conditions of components that may suffer from stress concentration, with stress gradients.…”

“…In many applications, machinery components subjected to fatigue loading must be designed in the so‐called very high cycle fatigue (VHCF) region, to sustain even more than 10 8 cycles. Automotive components, 1–4 high‐speed train components, 3–7 aircraft components, 3,4,8–12 as well as nuclear structural components 13 represent some examples of components to be designed in the VHCF region. The need to prevent the failure of these components is one of the main reasons for the growing interest toward the research on the VHCF response of materials.…”

Interior crack initiation during the very-high-cycle fatigue of railway wheel steel under axial loading and rolling contact loading

“…shattered rims is a form of rolling contact fatigue caused by subsurface and interior crack initiation [5][6][7][8]. In general, cracks of shattered rims initiated from the interior inclusion with a fatigue life more than 10 7 cycles, indicating a typical VHCF under rolling contact loading [9,10]. Therefore, the investigation of VHCF under rolling contact loading and the comparison study with VHCF under axial loading are with science significance and engineering demanding.…”

Effects of Molybdenum Addition on Rolling Contact Fatigue of Locomotive Wheels under Rolling-Sliding Condition

“…This kind of RCF damage required frequent re-profiling, which shortened the wheel lives [ 2 ]. In general, shelling was the result of the continuing propagation of RCF cracks and happened after high-cycle fatigue [ 12 , 13 ]. Thus, the occurrence of shelling was considered to be the end of RCF life in some experimental studies [ 14 , 15 ].…”

“…In the experiments, the RCF damage could be accelerated by adding liquid into the interface of wheel/rail contact [ 14 , 15 , 16 ]. Furthermore, previous studies proposed that shelling was the result of deteriorating RCF cracks [ 12 , 13 , 14 , 15 , 16 ], but the generation processes of shelling have not been explored systemically.…”