Rolling Contact Fatigue and Wear Behavior of High-Performance Railway Wheel Steels Under Various Rolling-Sliding Contact Conditions

Abstract

An experimental investigation was carried out to study and compare the response to cyclic loading of the high performance railway wheel steels ER8 EN13262 and SUPERLOS®. Rolling contact tests were performed with the same contact pressure, rolling speed and sliding/rolling ratio, varying the lubrication regime to simulate different climatic conditions. The samples, machined out of wheel rims at two depths within the re-profiling layer, were coupled with UIC 900A rail steel samples. The wear rates, friction coefficients and hardness were correlated with the deformation beneath the contact surface. The crack morphology was studied and the damage mechanisms were identified. The distribution of crack length and depth at the end of the dry tests was analysed to quantify the damage. The main difference between the steels lies in the response of the external samples to dry contact: SUPERLOS® is subjected to a higher wear and lower friction coefficient than ER8, this reduces the density of surface cracks that can propagate under wet contact conditions. The analysis of feedback data from in service wheels confirmed the experimental results

The Tribo-Fatigue Damage Transition and Mapping for Wheel Material under Rolling-Sliding Contact Condition

“…The pressure of the contact spot is distributed in a semi-ellipsoidal shape. The geometric sizes of the simulated wheel and rail are determined by means of the Hertz simulation rule, shown in Equation 1and Equation (2).…”

“…High-speed and heavy-haul railways are the main development areas for improving the global railway transport capacity in recent years. However, in modern high-speed and heavy-haul railway networks, wear and fatigue damage for wheel materials are important factors that reduce the service life of the wheel and rail system, and increase the risk of train operation [1][2][3]. In addition, trains often run on straight lines and curved lines with different radii, and repeatedly accelerate or decelerate during operation.…”

Experimental evaluation of the fatigue life of hydraulic gate cast iron rollers

“…Faccoli et al carried out an experimental investigation to study and compare the response to cyclic loading of the high‐performance railway wheel steels. The main damage phenomenon for both steels in the dry rolling‐sliding condition was surface‐initiated RCF due to ratcheting.…”

Experimental Investigation on the Wear and Damage Behaviors of Machined Wheel-Rail Materials under Dry Sliding Conditions

“…Wheel turning and rail grinding techniques have huge effects on the steady and reliable running of trains, which is conducive to ameliorate the wheel/rail interaction conditions. Currently, the studies on the friction and wear performance of wheel/rail materials primarily concentrate on the rolling-sliding contact mode, and the research contents mainly center on the hardness matching of wheel/rail materials [8][9][10], diverse wheel/rail creepages [11,12], selection of wheel/rail materials [13,14], laser treatment of wheel/rail materials [15][16][17] and different lubrication conditions [18,19]. Razhkovskiy et al [9] experimentally obtained the wheel/rail wear and damage data, and they found that the optimal range of the wheel-rail material hardness ratio H w /H r is (0.91-0.97):1, or close to 1:1.…”