Secondary steel making - Basic information for making steel in engineering.

1. STEEL MAKING
GROUP:
LE THI HAI YEN
LE THI NGOC QUYNH
TRAN THI LAI

2. OBJECTIVES
Presenting general steel making introduction
Giving knowledge about steel classification
Providing information about steel making

3. OUTLINE
 INTRODUCTION
 TYPES OF STEEL
 PROCESS OF STEEL MAKING
1. Basic Oxygen Furnace (BOF)
2. Electric Arc Furnace (EAF)
3. Secondary steelmaking

4. INTRODUCTION
 Steel is recyclable and hence is a “green
material”
 Steels are alloys of irons and others
elements
 Henry Bessemer (1813-1898) was the first
one developed process steel making
inexpensively

5. TYPES OF STEEL
 Depending upon the
percentage of carbon
 There are 3 types of steel
are: carbon steel, stainless
steel (inox) and alloy steel

6. BASIC OXYGEN FURNACE (BOF)
 Be a method of primary
steelmaking
 Carbon-rich molten Pig
iron (MPI) steel
(low-carbon steel)
converter

7. BOF PROCESS
1. Filling the furnace with the
ingredient
• Charging scrap steel into the
vessel, followed by hot metal
2. Blowing oxygen:
• Blowing high purity oxygen at
high pressure
3. Charging the fluxes:
• Forming slag
• May adding alloy

8. BOF PROCESS
4. Sampling and temperature
measurement
 Sampling: checking the chemical
content of the steel
5. Tapping the steel
 Tapping the slag out the container
Modern
BOS
vessel
about 40
minutes
350
tons of
steel at
a time

9. ELECTRIC ARC FURNACE (EAF)
 Heating charged material by means of an electric arc
 Being used to produce special quality steels (steels alloyed
with other metals)
 Being charged with "cold" material, normally steel scrap
 Mills producing steel (EAF technology ) “mini-
mills”
 Making 150 tonnes in each melt (90 minutes)

11. EAF PROCESS
 Similar to BOF process
 Some basic differences:
BOF process
• Using iron ore
• Self-sufficient in energy
• High in the capital
investment costs
EAF process
• Using scrap
• Using the heat
generated by arc
• Investment costs 
lower than BOF
proccess

12. EAF PROCESS

13. SECONDARY STEEL MAKING
Objectives of secondary steel making
Secondary steel making processes

14. OBJECTIVES OF SECONDARY STEEL MAKING
 De-oxidation => Removal of Oxygen
 Desulphurization => To sulfur concentrations as low as
0.002%
 Alloying => Addition of alloying elements
 Micro cleanliness => Removal of nonmetallic inclusions
 Inclusion morphology => Changing the composition of
remaining impurities to improve the microstructure of the
steel
 Superheat control => +/- 5 degree C

15. SECONDARY STEEL MAKING PROCESSES
 AOD (Argon Oxygen Decarburization)
 CLU (Creusot-Loire-Uddeholm)
 VOD (Vacuum Oxygen Decarburization)
 LF (Ladle Furnace)

16. AOD (ARGON OXYGEN DECARBURIZATION) PROCESS
 A process primarily used
in stainless steel making
 High grades alloys with
oxidizable elements:
chromium and aluminum

17. AOD PROCESS
 The metal will be transferred to an AOD vessel after
initial melting.
 The metal will also be subjected to three steps of
refining:
- Decarburization
- Reduction
- Desulphurization

18. CLU (CREUSOT-LOIRE-UDDEHOLM) PROCESS
 Be similar to AOD process for making
stainless steels
 Use liquid from an electric arc (EAF)
 Use superheated steam as the diluting gas
instead of argon (Ar) gas
 Be a mixture of oxygen, steam, argon,
nitrogen and air is blown from the bottom

19. CLU PROCESS
 The steam presence: control the temp around 1650-
1680*C
 The steam dissociates in the steel, so H2: Ar (AOD
process) and O2: a refining medium
 This process helps: control steel bath temperature and
take heat from the steel bath.

20. CONCLUSION
 INTRODUCTION
 TYPES OF STEEL
 PROCESS OF STEEL MAKING

21. REFERENCES
 http://www.istc.illinois.edu/info/library_docs/manuals/primmetals/chapter2.htm
 http://www.eef.org.uk/uksteel/About-the-industry/How-steel-is-made/step-by-
step/The-Basic-Oxygen-Converter.htm
 http://www.eef.org.uk/uksteel/About-the-industry/How-steel-is-made/step-by-
step/The-electric-arc-furnace.htm
 http://www.eef.org.uk/uksteel/About-the-industry/How-steel-is-made/step-by-
step/The-electric-arc-furnace.htm
 http://www.bssa.org.uk/sectors.php?id=99
 http://www.metsec.com/sustainability/environmental-impacts-of-steel/
 http://www.slideshare.net/AbhayDeo/presentation-steel-making

22. Thanks for
listening!