Lucchini RS S.p.A. (formerly Lucchini Sidermeccanica S.p.A. and where the acronym "RS" stands for "rolling stock") is an Italian company, fully owned by the Lucchini family through a financial holding called Sinpar S.p.A. and divided from Gruppo Lucchini, which was under Russian control of Alexei Mordashov and Severstal from 2005 till 2007. In 2008 the Lucchini family took back the control of Lucchini RS.Lucchini RS specialises in steel products such as railways products, steel casting, forgings, tool steels and forge ingots.The company headquarters is in Brescia, but the main plant is located in Lovere Bergamo on the west shore of Iseo Lake: the plant covers an area of 237,000 sqm including 147,000 sqm of factory buildings. Typical of this company is its ability to house on site all phases of production from the initial design to the finished products.[citation needed]The Lucchini RS Group is made of:In October 2007 Lucchini RS established a joint venture in China, Zhibo Lucchini Railway Equipment Ltd. This company is the Chinese market leader in the manufacturing of high speed railway wheels, axles and wheelsets.In 2010 the investment for a new railway rolling mill in Italy was completed and put into service.On 27 June 2014, Lucchini RS acquired from the Tribunal of Liege the bankrupt Valdunes company to manufacture railway products. The name of the new company is LBX SA.On 3 September 2014 Lucchini RS announced that it signed a preliminary agreement to acquire, by the end of 2014, 49% shareholding of Mamé Group, an important manufacturer of forged steel components based in Cividate Camuno Brescia. Mamé Group was eventually completely acquired by Lucchini RS and renamed Lucchini Mamé Forge.On 2 February 2015 Lucchini RS and Unipart Rail created a new joint venture called LUR or Lucchini Unipart Rail Ltd. The new business has an annual turnover of around £60m (about €75m) and employs over 300 people on two production sites, Manchester and Doncaster. Lucchini RS holds 60% of LUR..
A combination of instrumented wheelset measurements and numerical simulations of axle bending stresses is used to investigate the consequences of evolving rolling contact fatigue (RCF) damage on a passenger train wheelset. In a field test campaign, stresses have been monitored using a wheelset with four strain gauges mounted on the axle, while the evolution of wheel tread damage (out-of-roundness) has been measured on regular occasions. The strain signals are post-processed in real time and stress variations are computed. Based on a convolution integral approach, the measured wheel out-of-roundness has been used as input to numerical simulations of vertical dynamic wheelset-track interaction and axle stresses. Simulated and measured axle stresses are compared for cases involving combinations of low or high levels of rail roughness and the measured levels of RCF damage. The study enhances the understanding of how wheel tread damage and track quality influence axle stress amplitudes.
Abstract The wear behavior of two steels for tread-braked wheels (ER7+ and CLASS B+) against the same brake block cast iron was studied through pin-on-disc tests to understand the phenomena at the interface and compare the steels. The contact stress (0.61 MPa) and sliding speeds (0.52 and 0.62 m/s) were set considering the UIC 510-5 (E) for technical approval of monobloc wheels. The friction coefficient, weight loss of both the steel pin and cast iron disc, and pin hardness were correlated with the damage of the pin. In addition, a preliminary thermal finite element model was proposed to predict the temperature of the pin contact surface. The experiments showed that material transfer from the cast iron disc to the steel pin and the subsequent detachment of the adhesion joints caused high friction coefficient fluctuations. The removal of the adhesion joints probably promoted the detachment of steel particles from the pin, which could explain the high weight loss and remarkable delamination of the pin in some of the studied conditions. In contrast, small friction coefficient fluctuations and red oxide formation due to the temperature increase were detected when the material transfer was very limited. ER7+ steel showed lower weight loss and less damage than CLASS B+ at the lowest sliding speed, in contrast to what was observed at the highest sliding speed. Finally, the simulation showed that the maximum temperature of the pin contact surface varies between 61 and 97 °C, which is consistent with the presence of red oxide.
From a technological point of view, the decisive step during the manufacturing process of a special steel component, which is necessary to achieve the required use characteristics, is heat treatment: in fact, in order to obtain the highest qualities required by a steel, a specific heat treatment must be performed, in compliance with the main and very selective parameters established by the designer and the manufacturer of the component itself. However, aspects related to continuous product improvement and the heat treatment process must be addressed in a safe manner, fully integrated into the processing flows, and with respect for the environment. These aspects represent a cultural and ethical issue that must not be considered only in theory or worse as "slogans" but must become an intimate working knowledge of the hazards and measures to be implemented on processes and plants to prevent their risks and to make them environmentally sustainable. This report describes heat treatment processes for railway wheels, showing different solutions and comparing advantages and disadvantages. Different quenching process solutions are described, using different cooling media and modes, such as water and polymer solutions, having banned oil-based whole fluids in the most absolute way, for environmental and safety reasons.
Wheel microstructure significantly affects railway wheel performances. Although wheel microstructure traditionally consists of pearlite-ferrite, it is possible to detect some intermediate structures traces, for instance bainite, generated during the thermal treatment process. The difference in mechanical properties between pearlite and bainite causes stress and strain incompatibilities at their interface, and this gives rises to early crack initiation and propagation. This paper aims at investigating the presence of bainitic traces in a ferritic-pearlitic microstructure of a railway wheel through semi-analytical and numerical finite element simulations. The effect of bainitic spot shape, dimension and distribution is studied as well as stress and plastic strain in the proximity of the heterogeneities is analysed. The radius-interaxis ratio parameter, defined as the ratio between the bainitic spots radiuses and the distance between two neighbouring spots centres, is introduced to study the effect of circular-sectioned bainitic spots on the steel plasticity. It is observed that the bainitic traces form regions subjected to overstress and overstrain in the ferritic-pearlitic matrix and that the area of the bainitic spots influences the size of these regions. The bainitic spot distribution is found out to increase further the overstrain in case the radius/interaxis ratio is higher than 0.2, corresponding to about 11% of bainite in the ferritic-pearlitic matrix. Beyond this threshold value, bainite traces can compromise both RCF and wear response.
The effect of material plastic properties in solid-contaminated wheel-rail couplings was studied by simplified finite element models, considering typical couplings of steels following European and American standards. Analyses of non-contaminated contact were performed for comparison. It resulted that in clean contact there is a reciprocal influence, in terms of plastic strain, between the mechanical properties of both contacting bodies. By contrast, in solid-contaminated contact the performance of each contacting body depends mainly on its own properties. A zone of influence of the local contact between the contaminant particles and the main bodies was identified and compared with the damage observed in previous experimental results. Despite the simplifications of the numerical model, this zone can be visibly identified in harder materials and appeared to match the numerically estimated one. In softer materials, owing to the high strain even in the overall contact region, this zone could not be identified.
