http://jultika.oulu.fi/files/nbnfi-fe2018062726516.pdf

Slurry erosion of steel – Review of tests, mechanisms and materials

Three-body abrasive wear of fine pearlite, nanostructured bainite and martensite

https://www.tandfonline.com/doi/pdf/10.1088/1468-6996/14/1/014202

The first bulk nanostructured metal

The present study is concerned with the potential of high carbon, high silicon steel grades isothermally transformed to bainite at low temperature (<300°C). The first part gives an overview of the design principles, allowing very high strength and ductility to be achieved while minimising transformation duration. Wear and fatigue properties are then investigated for over 10 variants of such materials, manufactured in the laboratory or industrially. The results are discussed against published data. Tensile strengths above 2 GPa are routinely achieved, with, in one case, an exceptional and unprecedented total elongation of over 20%. Bainite plate thickness and retained austenite content are shown to be important factors in controlling the yield strength, though additional, non-negligible parameters remain to be quantified. Rolling–sliding wear performances are found to be exceptional, with as little as 1% of the specific wear rate of conventional 100Cr6 isothermally transformed to bainite. It is sug...

/pdf/evaluation-of-potential-of-high-si-high-c-steel-3h0dl03c8l.pdf

Evaluation of potential of high Si high C steel nanostructured bainite for wear and fatigue applications

A low-alloy high-carbon martensite steel with 2.6 GPa tensile strength and good ductility

Much recent work has been devoted to characterize the microstructure and mechanical properties bainitic nanostructured steels. The microstructure is developed by isothermal heat treatment at temperatures as low as 125–350 °C and adapted steel grades typically contain high carbon contents to achieve sufficient depletion of the B S – M S temperature range, and above 1.5 Si wt.% to suppress carbide formation during isothermal holding. On the latter, most of the published literature agrees on a limit of around 1.2–1.5 wt.% to suppress cementite in high carbon steels. For this reason perhaps, additions of Si significantly above this limit have not been investigated systematically in the context of nanostructured bainitic steels. The present work is concerned with the effect of up to ∼3 Si wt.% in a steel grade adapted to low temperature bainitizing. Tensile properties as compared to similar grades, though with lower Si contents, exhibited unrivalled combinations of strength and ductility, with above 21% total elongation for a UTS above 2 GPa. An attempt is made to explain the mechanical properties of this microstructure in terms of some of its most relevant and unique morphological and microstructural features.

/pdf/tensile-behaviour-of-a-nanocrystalline-bainitic-steel-3uw5ag67gg.pdf

Tensile behaviour of a nanocrystalline bainitic steel containing 3 wt% silicon

http://digital.csic.es/bitstream/10261/72601/1/196_WEAR_Leiro.pdf

Wear of nano-structured carbide-free bainitic steels under dry rolling–sliding conditions

It is not the first time that a consortium of steel makers, end users and scientists end up with unique approaches and developments in the physical metallurgy of steels. The present paper reveals the scientific and technological developments of a consortium sharing a common intrigue and interest for a unique microstructure, nanostructured bainite. Also known as low temperature bainite, its unique properties rely solely on the scale of the miscrostructure obtained by heat treatment at low temperature (150–350°C). Careful design based on phase transformation theory, some well known metallurgy facts and the necessary industrial experience were the ingredients for a further step towards the industrialisation of these microstructures.

http://digital.csic.es/bitstream/10261/101943/1/221_MST_CGM.pdf

Nanostructured steel industrialisation: plausible reality

NANOBAIN is the term used to refer to a new generation of advanced steels capable of producing by isothermal transformation at low homologous temperatures, T/Tm∼0.25 where Tm is the absolute melting temperature, a nanocrystalline microstructure, composed exclusively of two phases, thin plates of bainitic ferrite separated by C enriched austenite. Such alloys are exclusively designed on the basis of bainitic transformation theory and some physical metallurgy principles. In this work, by designing a new set of alloys capable of producing such microstructure, a further step toward the industrialization of NANOBAIN is taken. Some important industrial requirements, including circumventing the inclusion of expensive alloying elements and the need for faster transformations, are also considered. For all the alloys, the experimental results validate the design procedure and they illustrate that the NANOBAIN concept is a step closer to industrialization, probing that it is possible to obtain nanocristalline bainite in simpler alloy systems and in shorter times than those reported previously.

/pdf/composition-design-of-nanocrystalline-bainitic-steels-by-3v4ef4j9v4.pdf

Roberto Elvira

Papers

Tensile behaviour of a nanocrystalline bainitic steel containing 3 wt% silicon

Wear of nano-structured carbide-free bainitic steels under dry rolling–sliding conditions

Evaluation of potential of high Si high C steel nanostructured bainite for wear and fatigue applications

Nanostructured steel industrialisation: plausible reality

Composition design of nanocrystalline bainitic steels by diffusionless solid reaction