steel classification low alloy steel categorize in brief.

1. MATERIAL SCIENCE AND ENGINEERING
CLASSIFICATION
OF
STEELS

2. Ferrous Materials
Ferrous
Steels Cast iron
Low Alloy High Alloy
Tool steel Stainless steel

3. CLASSIFICATION OF STEELS

4. Low Carbon Steel
 Also known as Mild Steel
 Tensile strength of 555 N/mm
 Low carbon steel contain 0.30% C
 This steel can be used in flat rolled products
(sheet /strips) by using cold rolled and annealed
condition.
 The carbon contain for high formability steel is
used very less than 0.10%C ,with up to 0.4%Mn.
 It is used in automobile body panel, stamping,
forging, seamless tubes etc.

5. Low Carbon Steel
Applications
 automobile panel:
 Seamless tubes:

6. Low Carbon Steel
Applications
 Wire and rod nails:
 Concrete reinforcement bar:

7. Low Carbon Steel
Applications
 Stamping:
 Forging:

8. MEDIUM CARBON STEEL
Carbon content in the range of 0.3 – 0.6%.
Can be heat treated - austenitizing, quenching and then
tempering.
Increasing carbon %,and Mn %,it allows medium carbon
steel to be used quenched and tempered conditions.
Medium carbon steels have low hardenability
Addition of Cr, Ni, Mo improves the heat treating capacity.
Typical applications – Railway wheels and tracks, gears,
crankshafts.

9. MEDIUM CARBON STEEL
1. Gears:
2. Crankshaft:

10. MEDIUM CARBON STEEL
3. Couplings:
4. Axles:

11. MEDIUM CARBON STEEL
5. Railroad wheels:

12. MEDIUM CARBON STEEL
6. Suspension & steering parts:

13. MEDIUM CARBON STEEL
7.Inlet valves:

14. HIGH CARBON STEEL

15. HIGH CARBON STEEL
APPLICATIONS
1.Forging dies:
2.Railroad rails:

16. HIGH CARBON STEEL
APPLICATIONS
3.Springs:
4.Hammers:

17. HIGH CARBON STEEL
APPLICATIONS
5.Saws:
6.Cylinder lining:

18. HIGH CARBON STEEL
APPLICATIONS
7.Cold chisels:

19. EFFECTS OF ALLOYING ELEMENTS ON STEEL
Manganese contributes to strength and hardness; dependent upon the carbon
content. Increasing the manganese content decreases ductility and
weldability. Manganese has a significant effect on the hardenability of steel.
Phosphorus increases strength and hardness and decreases ductility and
notch impact toughness of steel. The adverse effects on ductility and
toughness are greater in quenched and tempered higher-carbon steels.
Sulfur decreases ductility and notch impact toughness especially in the
transverse direction. Weldability decreases with increasing sulfur
content. Sulfur is found primarily in the form of sulfide inclusions.
Silicon is one of the principal deoxidizers used in steelmaking. Silicon is less
effective than manganese in increasing as-rolled strength and hardness. In
low-carbon steels, silicon is generally detrimental to surface quality.
Copper in significant amounts is detrimental to hot-working steels. Copper can
be detrimental to surface quality. Copper is beneficial to atmospheric
corrosion resistance when present in amounts exceeding 0.20%.
Nickel is a ferrite strengthener. Nickel does not form carbides in steel. It
remains in solution in ferrite, strengthening and toughening the ferrite
phase. Nickel increases the hardenability and impact strength of steels.
Molybdenum increases the hardenability of steel. It enhances the creep
strength of low-alloy steels at elevated temperatures.