Cyclic Hardening and Fatigue Damage Features of 51CrV4 Steel for the Crossing Nose Design

Abstract

A crossing nose is a component of railway infrastructure subject to very severe loading conditions. Depending on the severity of these loads, the occurrence of structural fatigue, severe plastic deformation, or rolling fatigue may occur. Under fatigue conditions with high plastic deformation, cyclic plasticity approaches, together with local plasticity models, become more viable for mechanical design. In this work, the fatigue behavior in strain-controlled conditions of 51CrV4 steel, applicable to the crossing nose component, was evaluated. In this investigation, both strain-life and energy-life approaches were considered for fatigue prediction analysis. The results were considered through obtaining a Ramberg-Osgood cyclic elasto-plastic curve. Since this component is subject to cyclic loading, even if spaced in time, the isotropic and kinematic cyclic hardening behavior of the Chaboche model was subsequently analyzed, considering a comparative approach between experimental data and the FEM. As a result, the material properties and finite element model parameters presented in this work can contribute to the enrichment of the literature on strain-life fatigue and cyclic plasticity, and they could be applied in mechanical designs with 51CrV4 steel components or used in other future analyses.

Predicting the Remaining Useful Life of Light Aircraft Structural Parts: An Expert System Approach

“…The material and mechanical properties relevant to strain life curves used to determine the observed landing gear leg RUL made from a 6150 steel alloy, also referred to as the 51CrV4 steel alloy, were determined through rigorous literature research. This involved a review of academic journals, industry publications, and technical reports [27][28][29][30][31][32][33][34], leading to the identification of key material fatigue-relevant properties. The properties of this alloy include a density of 7850 kg/m 3 , Young's modulus of 2.038 × 10 11 Pa, Poisson's ratio of 0.29, strength coefficient of 1.1 × 10 9 Pa, strength exponent of −0.093, ductility coefficient of 0.478, ductility exponent of −0.684, cyclic strength coefficient of 1.476 × 10 9 Pa, cyclic strain hardening exponent of 0.0651, tensile and compressive yield strength of 1.042 × 10 9 Pa, and tensile ultimate strength of 1.2773 × 10 9 Pa. Program-controlled element order and adaptive element sizing, with a maximum element size of 1.4 × 10 −2 m, have culminated in an acceptable RUL regarding prediction expectancy based on the recorded number of airplane landings in the airplane technical logbook.…”

Monotonic and Fatigue Behaviour of the 51CrV4 Steel with Application in Leaf Springs of Railway Rolling Stock

“…Comparing with tempered 51CrV4 steel at 540-650 • C [6], the ∆W t − 2N f model predicts the higher fatigue resistance of 51CrV4 steel when tempered at 450 • C, due to the coefficient κ t and exponent α t both being higher.…”

“…In the presence of plastic deformations, the fatigue strain-based models such as the CMB are suitable [53][54][55]. The CMB model relates the number of reversals to failure, 2N f , with the total strain amplitude, ε a , via Equation (6), such that…”

“…The same trend is verified when the median model, MM [73], is considered: C (as in the case of the steel investigated in this article), the fatigue resistance is higher for 100 reversals (ε = 0.0254), approximately; that is, LCF + HCF. On the other hand, 51CrV4 steel in [6] will tend to have greater resistance for lives of less than 100 reversals.…”

“…In addition to being used for road and rail suspension vehicles, the 51CrV4 steel grade has been used in the design of industry machinery components such as gears, pinions, forged crankshafts, steering knuckles, connecting rods, spindles, pumps, and gear shafts [3][4][5]. Additionally, the characteristics of this steel grade have also been investigated for application in railway rails [6]. As a suspension component in cargo vehicles, for example, leaf springs are continuously subjected to dynamic loads, which increase the likelihood of failure due to fatigue phenomena.…”