Steel is an alloy of iron and carbon that is widely used in construction and manufacturing due to its high strength and low cost. There are several grades of steel depending on carbon content and other alloying elements. Low carbon steel has a very low carbon content below 0.3% and is the most commonly produced grade due to its low cost. Medium carbon steel has 0.3-0.6% carbon and can be heat treated to increase strength. High carbon steel contains 0.6-1.4% carbon and is very hard but brittle. Stainless steels contain at least 11% chromium which gives them high corrosion resistance.

1. STEEL
• INTRODUCTION
• PHYSICAL PROPERTIES OF STRUCTURAL STEEL
• GARDES OF STEEL
Prof. Suyash Awasthi
Deptt of Civil Engineering
GGITS, JBP

2. Introduction

3. Physical properties of Structural Steel
• Steel is an alloy of iron and carbon and other
elements. Because of its high tensile strength
and low cost, it is a major component used in
buildings, infrastructure, tools, ships,
automobiles, machines, appliances and
weapons
• Chemical Composition: C=0.45%, Mn=0.75%,
P=0.04% max, S=0.05% max
• Density : 7.872* 10³ kg/m³
• Modulus of elasticity : 201 GPa (kN/mm2)
• Thermal expansion (20 ºC) : 11.7*10-6 ºCˉ¹

4. Physical properties of Structural Steel cont…
• Specific heat capacity : 486 J/(kg*K)
• Thermal conductivity : 50.9 W/(m*K)
• Electric resistivity: 1.62*10-7 Ohm*m
• Tensile strength (hot rolled) : 565 MPa (N/mm2)
• Yield strength (hot rolled) : 310 MPa
• Elongation (hot rolled) : 16%
• Hardness (hot rolled) : 84 RB (Brinell / Rockwell
Hardness)

5. GRADES OF STEEL

8. GRADES OF CONCRETE

9. Low Carbon Steel
• Plain carbon steels - very low content of alloying
elements and small amounts of Mn
• Most abundant grade of steel is low carbon steel
- greatest quantity produced; least expensive.
• Not responsive to heat treatment; cold working
needed to improve the strength.
• Good Weldability and machinability
• High Strength, Low Alloy (HSLA) steels - alloying
elements (like Cu, V, Ni and Mo) up to 10 wt %;
have higher strengths and may be heat treated.

12. Medium Carbon Steel
• Carbon content in the range of 0.3 – 0.6%.
• Can be heat treated - austenitizing, quenching
and then tempering.
• Most often used in tempered condition –
tempered at site
• Medium carbon steels have low hardenability
• Addition of Cr, Ni, Mo improves the heat treating
capacity
• Heat treated alloys are stronger but have lower
ductility
• Typical applications – Railway wheels and tracks,
gears, crankshafts.

13. High Carbon Steel
• High carbon steels – Carbon content 0.6 –
1.4%
• High C content provides high hardness and
strength. Hardest and least ductile.
• Used in hardened and tempered condition
• Strong carbide formers like Cr, V, W are added
as alloying elements to from carbides of these
metals.
• Used as tool and die steels owing to the high
hardness and wear resistance property

14. TOOL STEEL

15. STAINLESS STEEL
• Stainless steels - A group of steels that contain at
least 11% Cr. Exhibits extraordinary corrosion
resistance due to formation of a very thin layer of
Cr2O3 on the surface.
• Categories of stainless steels:
– Ferritic Stainless Steels – Composed of α ferrite (BCC)
– Martensitic Stainless Steels – Can be heat treated.
– Austenitic Stainless Steels – Austenite (ϒ) phase field is
extended to room temperature. Most corrosion
resistant.
– Precipitation-Hardening (PH) Stainless Steels – Ultra
high strength due to precipitation hardening.
– Duplex Stainless Steels – Ferrite + Austenite

16. Properties and Uses of Various Stainless steels

18. Thank You…