This project consists of two distinct research streams – one
focused on potential new steels for rail wheels and the other
investigating the potential use of Austempered Ductile Iron as a
replacement for various wagon parts traditionally cased in steel.
Railway wheels are subjected to an arduous environment of
mechanical and thermal stresses, rolling/sliding wear and other
forces, causing significant degradation and making them one of the
most important and maintenance intensive components of a railway
system. Recent steel alloy developments have provided a significant
opportunity to reduce costs and improve system reliability through
the application of more resilient wheel/rail materials.
This project aims to expand the knowledge of the
bainitic-martensitic steels as a preliminary step towards
full-scale production and service trials, and investigate the use
of Austempered Ductile Iron for rail vehicle components to extend
their service life and their ability to operate under higher loads.
The initial part of the project proved the advantages of
martensitic steels, with a project extension working to:
- Evaluate quenching schedules that have the potential to produce an
acceptable residual stress distribution in martensitic steel wheels
- Develop a finite model for the quenching process which captures the
theoretical heat flow and distribution to enable evaluation of
residual stress in martensitic steel wheels
- Verify results of model and recommend a suitable quenching
procedure for production of martensitic steel wheels.
The project was evaluated by STEM Partnerships in 2006 and was
estimated to have the potential to deliver a risk-free-value to the
rail industry of $84.6 million over 30 years, and an estimated
value of 62.2 million taking into account risks associated with
delivering the technology. A number of Rail CRC and rail industry
participants have expressed significant interest in the outcomes of
this project, however the key challenge will be the high capital
costs of industrial scale steel heats and wheel trials.
Results to date:
- Literature reviews completed
- Advanced testing programs of existing and proposed new materials
completed – testing shows that bainitic-martensitic steels
offer substantially higher wear resistance
- Austempered Ductile Iron proven to be potential suitable material,
offering lower maintenance costs for some wagon components and
capacity to carry more freight for a given gross weight limit.
- Commenced development of finite element model of wheel quenching.
- Commenced determination of finite element model validation.
Future outcomes:
- Final development and report on recommendation of suitable
quenching procedure for production of martensitic steel wheels
Project Leader: Dr Bernard Chen (Monash University)
Project Manager: Tim Constable (QR)
