Centre for Material and Fibre Innovation
ITRI
As in any university situation the nature of the research program reflects a combination of the interests of the staff as well as the availability of students and research funding. The following outlines areas of current activity but these could be easily broadened depending on the industry interests.
This is a very broad research program that considers both the steel industry as well as the automotive industry aspects. Current topics include:
Some key papers:
Our work on the ultrafine grained steels through strain induced transformation is widely known. We still maintain a small program on this, largely in collaboration with NIMS in Japan. Our real focus at present is to understand the fundamentals better and in particular the deformation structure evolution in the austenite prior to or during the transformation. We are considering a range of in-situ techniques for this at present. We have also a program related to the new nanostructured bainities developed by Bhadeshia and co-workers. We have produced a range of structures and are considering their dynamic properties as well as undertaking detailed microstructural characterization including APT. Another project is considering the strength ductility balance of ultrafine structured steels produced by a range of methods. This is linked to a more general program on nanostructured metals.
Some key papers:
We have had a number of projects examining the deformation and dynamic and post deformation softening behaviour of steels. This has largely involved advanced use of our EBSD equipment to identify the key features of the microstructure evolution. We have also examined a range of model alloys and recently commenced new work related to strain induced precipitation in Nb microalloyed steels, particularly under multi-pass and strip mill conditions - areas that have not received much attention to date. We are also interested in the potential loss of Nb for latter precipitation strengthening in the production of thick plate.
Some key papers:
Most of this work has previously been related to warm rolling. However, with our new thrust into strip casting this research will consider a much broader range of conditions and microstructures.
Some key papers:
We have recently commenced a program to re-evaluate precipitation hardening in HSLA steels. This has been driven by the recent work of JFE where they have produced a low C 780MPa grade and appear to also have 980 grade. This is said to be through the control of the precipitate size and spacing and some limited APT work by our group has confirmed much of this although it appears other factors are also involved. In this new study we will more closely consider the interaction between phase transformation and precipitation for different alloy systems.
Key paper:
This is largely linked to the TMCP of AHSS and will in the future focus on the potential to develop advanced steels through the strip casting or other near net shaped casting and TMCP routes. We are extending the TMCP TRIP steel work to consider other much higher strength microstructures. Also once we have the ability to make our own melts we will be pursuing other ideas related to standard TRIP compositions. Another thrust for this year will be TWIP steels and in particular designing the compositions for the balance between forming and crash conditions. We would also be interested in pursuing research related to the transformation of more basic TMCP plate and strip steels and using new modeling techniques combined with our excellent experimental capabilities.
Besides the work on bake hardening of AHSS we are also continuing work related to strain ageing under wire drawing conditions. This includes developing a kinetic model as a function of the deformation conditions, composition, temperature etc. We will also examine the various stages of ageing using APT.
This is a new program that is about to commence in late 2008. It will involve developing improved models in conjunction with COPRA a software supplier and a range of industry partners. The steels to be considered range from simple C steels in the soft or recovery annealed condition, through to stainless steels. There is also some interest in considering advanced steels and shapes for the automotive industry
Our current focus in this area is in the development of new fluid bed diffusion coatings that permit hard surface layers to be created on the final steel product at low temperatures. The lower the treatment temperature the less frequent are problems associated with distortion. We have developed mathematical and physical models of the process and are using these to support our commercialization effort sin this area.
Our group has undertaken a wide range of projects for the automotive and steel industries involving advanced modeling concepts and in particular the incorporation of metallurgical phenomena into these models. These have included:
