Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 1

Possible IMF Research Projectduring 2009-2010

Assistant Professor Lifeng Zhang

IMF 2008 Fall Meeting

Department of Materials Science and EngineeringMissouri University of Science and Technology (Missouri S&T)

Rolla, MO 65409-0330Tel: 573-341-4776

Email: zhanglife@mst.edu

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 2

What We Can Do for OtherResearches ?

- Fluid flow, heat transfer and inclusion during ingotteeming process

- Solidification modeling – including segregation

- Design of runner, ingate….

- Inclusion investigation

- Filtration

- Ladle refining (argon stirring, AOD, VOD, RH…)

- Reaction between refractory and slag, moltensteel and inclusion absorption

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 3

Suggestions

- IMF are welcomed to visit my university (MissouriS&T) to make a presentation to all students inmetallurgical engineering, setting up scholarships,internships;

- Students from Missouri S&T attend IMF futuremeetings and plant tour;

- Support master research project;

- … …

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 4

Examples 1: Solidificationof Ingot Teeming

Process

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 5

Transient, Multiphase Flow— Volume Fraction of Steel

7s 10s 13s 17.5s

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 6

Temperature Distribution AfterTeeming

328s 728s 953s

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 7

Example 2: Filtration during SteelCasting Process (Spout Control

and Inclusion Removal)

- One or two master students

- 2 year duration

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 8

Problems during Bottom IngotTeeming Process That We Found?

- Lots of big inclusions from air absorption (purealumina inclusion clusters);

- Big mold slag inclusions.

Very possible reasons:

- Big spout generation at the start of teeming (burningpowder bag, entraining powders, absorbing air)

- Argon shrouding issue??

Possible Solutions:

- Plate mold board?

- Filters at the ingate.

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 9

Big Spout with High Teeming Rate

0.01s 0.1s 0.2s 0.5s 0.75s 0.9s 1.0s 1.1s 1.2s 1.3s 1.5s

Teeming rate: 61.4 tonne/min at ladle, 503.2 inch/min in ingot

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 10

Filters for Steel

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 11

Filtration for Ingot TeemingProcess

Raiber et al, 1995

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 12

Filtration Ingot TeemingProcess

Raiber et al, 1995

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 13

Examples 3: Fluid Flow andMass Transfer in Gas-

Stirred ladles

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 14

Flow Field and Bubble Distribution

Flow field (m/s) Gas volume fraction(%)Gas Flow rate = 0.113 Nm3/min

→ 0.254 (bottom) ~ 0.775 (top) m3/min Csk=0.10, Csε=0.08

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 15

Flow Field in 3D

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 16

Examples 4: InclusionInvestigation during

Ingot Teeming Process

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 17

Alumina Inclusions: Acid Extraction

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 18

Inclusions (Acid Extraction)

180s 300s 540s

1140s 2040s

Al22.59％ Si20.95% Ca 19.33 Cr9.18％ Fe27.95％ s

2940s

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 19

NSF Project: GOALI - InclusionNucleation, Growth, Transport andEntrapment during Steel Casting

Three Years, Two Ph.D. students

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 20

Complexity of Steel Refining Technology

1. Phenomena (microscopic scale)– Multiphase thermodynamics & heat transfer

(alloy melting, slag-metal interface reactions, steel solidification)

– Nucleation, collision, and growth of particles

– Gas bubble motion and particle attachment

– Mass transfer (mixing, segregation, particle motion, etc.)

– Particle entrapment (at top surface or in steel shell)

2. Turbulent multiphase fluid flow in vessel (macro-scale)– RH Degasser or Gas-stirred Ladle Refining

– Tundish

– Transfer between vessels (eg. nozzle flow)

– Casting

3. Scales– Time (10-9 – 10+3 seconds)– Length (1 nm – 10m)

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 21

Objectives of NSF Project

Develop fundamental modeling system to predictinclusion quantity and size distribution evolutionduring steel processing, including effects of

– nucleation,

– growth,

– collisions,

– bubble interactions,

– turbulent flow transport,

– entrapment by the solidifying steel

Missouri University of Science & Technology zhanglife@mst.edu L. Zhang 22

Current Status of NSF Project

Firstly submission to NSF: February 15, 2008.Failed: informed on August 15, 2008

Second submission to NSF: October 1, 2008Will be informed on March 31, 2008

It is very competitive to get funding from NSF.