Steel Poll 2

To maximise clear up any confusion I bring you the second poll. Please justify your selection in the comments section.

Second Steel Poll

Second Steel Pole

Making Podcasts

More podcasts this weekend…

Crystallographic texture and intervening transformations

Stress of Strain affected martensitic transformation

Quantitative Metallography of Deformed grains

Steels for Fusion

New Podcasts

I made three new podcasts with Prof. Harry Bhadeshia on his latest papers on transformation texture, the new delta-Trip steels and on prediction of Hot Strength of ferritic steels.

The work on transformation texture is from Saurabh Kundu’s thesis were Patel and Cohen’s model has been shown to correctly predict the orientation relationship between ferrite and austenite after martensitic transformation. It’s shown that variants are selected by free energy differences that can be calculated depending on the orientation.

The delta-Trip steels were developed as a result of the prediction of neural networks, were after the neural network was made computer optimisation was used to try and maximise the mechanical properties. This work was done with Saurabh Chatterjee in collaboration with Murugananth Marimuthu. Both Saurabh Kundu and Saurabh Chatterjee completed their PhD’s at Cambridge while visiting from Tata Steel, Murugananth Marimuthu is a previous member of the phase transformations group, and has now also joined Tata Steel’s research and development section.

The work on Hot Strength of ferritic steels is the part of Radu Dmitriu’s topic of research. A neural network model of the hot-strength of ferritic steels. It was observed from the neural network that the strength is expected to suddenly start to decrease at 800 Kelvin, which can has been explained to be due to changes in the mobility of dislocations.

Addendum

According to wordpress documentation these links should get added to the rss feed of this bainite blog as enclosures.

Podcast: Hot Strength

Podcast: Delta Ferrite

Podcast: Transformation Texture

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Subscibe to RSS Feed for posts I remember to add to Podcasts category

L6 Steel Kinetics

This steel is popular for use in knives and swords like the Samurai sword “Bainite Katana”.

Custom Howard Clark L6 Katana
The Bainite Katana is made of a special purpose low-alloy steel. It is very resistant to bending, to the point of near unbreakability. These blades can be made lighter and thinner and still remain stronger than conventional steel or 1086. The blades are also springy rather than soft, they will flex more than a normal blade, but the shape will not be altered. These blades are excellent for tameshigiri as well as general sword work.

Composition; I found the composition of L6 is something like: Fe-0.7C-0.5Si-1.75Ni-0.5Mo-0.25V-0.25Cu.

I calculated the time-temperature-transformation diagram, i’m not too sure about the accuracy bainite start temperature using this program, I would like to be able to find the experimental results for this alloy.

Depending on the bainite start temperature, the kinetics are fast enough to allow isothermal transformation to bainite on a reasonable timescale, at temperature of around 300 C which would give a high strength bainite. Howard Clarke sells the swords with as a martensite/bainite sword. If the bainite start temperature is higher it would be easy to get a mixed microstructure.

I should try to make a prediction of bainite start temperature – I made a neural network model for this.

Even without carbide precipitation transformation results in a large volume fraction of bainite.

Presumably if the bainite Katana is used in marteniste/bainite condition it is produced by continuous cooling or by quenching. Quenching would be good if it can be done in at a rate which gives martensite on the outside of the blade for sharpness and hardness, and bainite in the centre to give toughness. The other possibility is that the continuous cooling gives a mixture of bainite and martensite at every location. This can have a higher strength or hardness than martensite alone because austenite will get enriched in carbon as the bainite transforms, increasing it’s contribution to the strength.

I’d really like to have a look at the microstructure of these swords to see what structure the bainite has. Also it would be interesting to measure the mechanical properties of the alloy in the same condition – I need to look for some literature on L6 I guess. It looks like they should be strengthened by carbides and by copper precipitation.

Howard Clark who makes these swords has a webpage at mvforge.com.

–edit 6 October 2007–

Corus Symposium

On 11th-12th April 2007 I attented the first annual Corus-Academia Symposium, which was held at a previous residence of mine, Tapton Hall in Sheffield.

It was really good to see this event being organised by Corus, bringing together many of the students they sponsor and research staff from academia and industrial researchers. I would recommend any company in a similar situation to organise a similar event – I think it succeeded in benefiting both the students and the company. The conference was held over two days, starting at 11 am and ending at 2 pm. This gave time to travel to and from Sheffield without too much trouble, or atleast it wasn’t too difficult to get there and back on the train from Cambridge.

There were 18 oral presentations were made in 4 sessions and around 30 posters presented.

Click to see more photographs

The poster I presented at the symposium was based on my phd work, titled Bulk Nanocrystalline Steel. During presentation of the best poster award, the first thing that one of the organisers said is that the poster should have the name of the author, and sponsors, so I don’t think they were impressed by my attempt to comunicate only the important information. Probably to keep this style I should have had another small sign with my name and photograph on it, however my name was in the progamme, and Corus should know who in their company is working on what projects. One thing that did upset me is that I thought I would be able to stand next too my poster to talk to anyone who was interested during the poster sessions, this was overly optimistic, and made difficult by the layout of the poster stands. I did manage to talk to a few people about my work, I think the poster atleast succeeded in being a good starting point for a discusison.

Conference Programme

Wednesday IIth April
11:00 Registration desk open Tea / coffee Loading of oral presentations and erection of posters
12:00 POSTER SESSION in dining hall with buffet lunch
Chair Prof. Rob Boom
13:00 SESSION 1
• Welcome / Corus Prof. Rob Boom
• Welcome/Sheffield Prof Mark Rainforth
• Strain induced precipitation in multipass rolling Vishwa Nagarajan
• Internal stresses in steels Ellie Clarke
• Development of bimodal grain sizes in TMCR Debalay Chakrabarty

• Microstructure & toughness of high strength, hot rolled strip steels Eric Maina
• An application of Kinetic Monte Carlo techniques in the modelling of strain ageing
Alex Gator
• Damage evolution in Free Cutting Steels Alistair Foster
15:30 Tea & Coffee, conservatory
16:00 SESSION 2 Chair Dr Peter Morris
• The non-contact ultrasonic inspection of hot, moving steel Iain Baillie
• Ultrasonic measurement of liquid steel cleanness Alex Currie
• Acoustic diagnostics in a hot strip mill David Murray
• What non-contact sensors can offer to the steel industry in terms of material characterisation Dr Claire Davis
17:30 Close
19:00 Bar
19:30 Dinner

Thursday I2th April
09:00 SESSIONS Chair Prof Andy Howe
• Overview of Corus research at NIMR Dr Rene Duursma
• Rapid testing of organic coating degradation using FTIR Jen Wray
• Flame-assisted CVD Paul Youngson
• Fine-scale mapping for environmental analysis Kevin Jackson
10:30 POSTER SESSION in dining hall with tea/coffee
11:20 SESSION 4 Chair Dr Tony Jones
• A hot strip mill work roll temperature model Daniel White
• The performance on non-sharp defects in service Anthony Horn
• Characterisation of connection mechanisms within road safety barriers Andrew Bayton
• Behaviour of composite structures during the cooling phase of a fire Charlotte Roben
• Symposium wrap-up Dr Tony Jones
13:00 Buffet Lunch & prizes
14:00 Close / Posters down

POSTERS: Wednesday 11*, 12-13:00, and Thursday 12th, 10:30-11:20
Iain Baillie, Corus/Warwick: The non-contact ultrasonic inspection of hot, moving steel
Arghya Deys, Sheffield: The Interactions of Zirconia Particles and other Inclusions of Liquid Steel with Zirconia Based SEN Walls
Tim Evans, Birmingham: Concentrations of PCBs and Chiral signatures of matched air and soil samples on a global scale
Xinjiang Hao, Birmingham: Multi-frequency electromagnetic sensors for the measurement of microstructure
Andrey Kostryzhev, B’ham: Role of precipitates on Bauschinger effect in large diameter
steel pipe processing
Huan Li, Birmingham: Modelling of mechanical property and damage recovery for a
pipe steel in annealing process
Ed Marsden, Corus/Sheffield: Thermal neutron detectors for security applications
Glyn Martin, Swansea: Factors influencing the long term durability of coated products in worldwide climates
Mayorkinos Papaelios, B’ham: Rail research at the University of Birmingham
Mathew Peet, Cambridge: Tempering of Low temperature Bainite
John Pillai, Greenwich: Results from plant trails to evaluate on-line wall friction tester
Mark Potter, Warwick Ultrasonic texture measurement of strip (UTMOST)
Guixiang Qin Microstructural evolution analysis on an E911 steel using the Leicester: EBSD method
Jody Turner, Sheffield Metallurgical sub-structure development in multipass rolling

Others expected :-
Yoseph Tefasse, Cranfield: Rolling system design optimisation using thermal and soft computing technique
Bin Kamal, Sheffield: Monitoring Airborne Pollution using Tree Bark -
Dmitry Borisoglebsky, C’field: Incorporation of cost modelling into process simulation
Natalie Kaniuka, Salford: Atmospheric pressure plasma CVD of SiON
Richard Wood, Cardiff: Processing routes of electrical steels
Ben Ward, Sheffield Hallam: Organic coatings based on polymer-clay nano-composites
Chris Taylor, Swansea: Analysis of run-off from coated organic steels
Stephen Essex, Warwick: Ultrasonic characterisation of texture in aluminium sheet in correlation with electron back-scatter diffraction
Yichao Fan, Warwick: Crack depth measurements using non-contact ultrasound
Ed Marsden, Corus/Sheffield: Large Area High Efficiency Neutron Detector
Stephen Turner, Cardiff: Grain-to-Grain Field and Loss Variation in Electrical Steel
Christopher Vardon, Cardiff: Domains and microstructures in electrical steel