1. STEELS
Persistence is to the character of man as Carbon is to
the Steel
by Md. Asfaque
Production Engineer
SRBWIPL
2. Content Layout
Engineering Materials and its Classification
Steel and its types
Classification of Plain Carbon Steels
Manufacturing Processes of Steels
Stainless Steel and its Composition Diagram
How Stainless Steels are made?
World Steel Production
Microstructure of Plain Carbon Steel
Iron Carbon Phase Diagram
Conclusion video
Cold rolled Steel Vs Hot Rolled
3. Classification of Engineering Materials
Engineering
Materials
Metals
Ferrous
Metals
Non Ferrous
Metals
Non Metals
Synthetic
materials
Natural
Materials
FerrousMetals
Steels
Cast Iron
Wrought Iron
4. STEELS and its types
It is an alloy of Iron, Carbon and other elements with a Carbon Content upto a
maximum of 2 wt%.
Carbon Steels
Plain Carbon Steels
Are alloys with definite ranges of
Carbon and a max of 1.65 wt% Mn,
a max of 0.6 wt% Si & Cu and
maxima of Sulphur and Phosphorus
Alloy Steels
Same constituents, in addition
also contains Al, Cr, Mo, Nb, Ni,
Ti, W, Vd, Zr , etc
5. Classification of Plain Carbon Steel
PlainCarbonSteel
Dead Mild Steel
(< 0.15%)
Low Carbon Steel
(0.15%- 0.45%)
Medium Carbon Steel
(0.45%- 0.8%)
High Carbon Steel
(0.8%- 2%)
6. Manufacturing Processes of Steels
Principal methods applied in the manufacture of Steels are:-
Bessemer Process
Cementation process
Crucible Process
Open Hearth Process (Siemens- Martin Process)
Duplex Process
L-D process
Electric Process
7. Stainless Steel – It is that steel which when correctly heat treated and finished, resists
oxidation and corrosive attack from the most corrosive media.
STAINLESS STEELS
Martensitic
(11-18% Cr,
0.1-1.2% C)
Ferritic
(10-27% Cr,
0.12% C)
Austenitic
(18-35% Cr,
<35% Ni
Duplex
(21-27% Cr,
1-8% Ni,
0.05-3% Cu,
0.05-5%
Mo)
Precipitation
Hardening
(15-17% Cr,
3-5% Ni &
Cu & traces
of Al, Nb)
Source: Encyclopaedia Britannica
9. How Stainless Steels are made?
Melting
• Melting iron scrap and additives in an EAF
• High power electrode heats the metals to create a molten mixture
Removing
Carbon Content
• AOD:- Injecting Argon gas reduces Carbon
• VOD:- molten steel is transferred to another chamber and Oxygen is injected into it. A vaccum then removes
the vented gases reducing Carbon Content
Tuning
• To ensure that the metal meets the requirements by balancing and
homogenisation of temperature.
Forming
• Foundry used to cast the desired shape viz, Blooms, Billets, Slabs, Tubes and Rods
10. Depending upon the grade or format,
Annealing
Cold
rolling
Hot
rolling
Quality Control
Finishing
cutting
Descaling
12. Cold rolled Steel Vs Hot rolled Steel
At high temperatures over 1,700˚F, which is above the
re-crystallization temperature for most steels.
Hot worked steels are less stronger than standard cold
rolled steels.
Less control over its final shape, making it less suitable
for precision applications.
Lot cheaper in relative to cold rolled steel
A scaled surface
Slight distortions
Railroad tracks and construction projects often use hot
rolled steel
Cold rolled steel is essentially hot rolled steel that has
been through further processing. Once hot rolled steel
has cooled, it is then re-rolled at room temperature.
Cold worked steels are typically harder and stronger
than standard hot rolled steels.
• Better, more finished surfaces with closer tolerances
• Smooth surfaces that are often oily to the touch
• Bars are true and square, and often have well-defined
edges and corners
• Tubes have better concentric uniformity and
straightness
• Computer-cabinet hardware; small appliance parts; and
light industrial applications such as tool boxes, shelving,
and lighting often use cold rolled steel