Case History: UNIBALL component in ADI cast iron for the railway industry
Production of spheroidal graphite cast iron Uniball for DAC
(Digital Automatic Coupling)
Project Context and Objectives
In the context of rail mobility, Zanardi Fonderie S.p.A. has redesigned the UNIBALL component in ADI cast iron as an alternative to solutions currently being validated and obtained by welding steel components.
Uniball is the key component for the operation of the innovative DAC (Digital Automatic Coupling) system, which enables the automatic coupling and uncoupling of freight cars and the digitization of railway infrastructure. Its operation makes the railway system more efficient, safe, automated, and interconnected.
The European Union is also moving towards the DAC (Digital Automatic Coupling) system, with an investment plan that envisages its implementation by 2030 on wagons operating across the continent, revolutionizing the rail freight sector towards sustainability and digitalization.
The project is part of the research program of spoke 11 “Innovative Materials and Lightweighting” promoted by MOST – National Center for Sustainable Mobility and coordinated by the University of Bologna.
Selection and Characteristics of ADI Cast Iron
With the aim of identifying a material capable of promoting the lightening of railway structural components, Zanardi Fonderie has selected high-performance austempered cast iron (ADI), specifically ADI EN-GJS-1050-6/C, compliant with EN 1564, as an alternative to proven steel solutions.
This is an ausferritic matrix cast iron obtained through austempering heat treatment, which gives it high mechanical properties combined with greater intrinsic lightness compared to steel, whose density is 10% higher than that of cast iron.
Reference sectors and application
The component is part of the innovative DAC system, which enables automatic coupling and uncoupling of freight wagons: it is a key component for the digitalization of railway infrastructure, whose adoption makes the railway system more efficient, safer, more automated, and more interconnected.
The component is used in rail transport, specifically in freight transport. The work carried out can be classified within the fields of transport, sustainable mobility, and metallurgy, with a focus on the optimization of casting and heat treatment technologies.
Problems solved and benefits
The INNOADI project has completed the validation of the prototype in an industrial environment, achieving the following benefits:
Weight reduction
Effective reduction in component weight of -2.2 kg, partly due to the lower density of cast iron (weighs 10% less than steel) and partly to structural redesign;
Lower emissions
Emissions reduction for the entire freight car fleet
Carbon Footprint Reduction
Reduction of the carbon footprint of the component by 13%, achieved through optimization of the casting and heat treatment process.
Optimized Production Process
Optimization of the production process, which has enabled more efficient use of binders and improved the net/gross yield of the casting, with a positive impact on emissions reduction and the overall sustainability of the production process.
Simplified Production Process
Simplification of the production process (reduction in production times and total cost) thanks to the creation of a monolithic piece with net-to-shape geometry, which has made it possible to optimize mechanical processing and eliminate the welding phase.
Zanardi Fonderie continues to invest in applied research to transform technological innovation into concrete and sustainable solutions for the mobility of the future. With INNOADI, ADI cast iron confirms its role as a leader in change focused on efficiency, lightness, and industrial sustainability.
Validation and Implementation Prospects for ADI Cast Iron in the DAC System
The INNOADI project has experimentally validated the use of ADI EN-GJS-1050-6/C austempered cast iron as an alternative material to S355 steel for the UNIBALL component of the DAC system. The monolithic piece, produced using the net-to-shape process, showed a mass reduction of 2.2 kg (-17.1%) and the elimination of the welding phase, simplifying the production flow and reducing unit costs. The optimization of the casting and heat treatment parameters made it possible to achieve a lower unit carbon footprint and an increase in net/gross yield.
Financed by the European Union – NextGenerationEU (National Sustainable Mobility Center CN00000023, Italian Ministry of University and Research Decree n. 1033 – 17/06/2022, Spoke 11 – Innovative Materials & Lightweighting).
The opinions expressed are those of the authors only and should not be considered as representative of the European Union or the European Commission’s official position. Neither the European Union nor the European Commission can be held responsible for them.
Case History
Real cases explaining the development of client projects
