Module 1: Steelmaking Fundamentals
  Lecture 1: Types of steels, History of modern steelmaking and Indian scenario
 

 

Types of steels: Below are given some applications. Details can be looked into references given at the end of the lecture.

Broadly we have either plain carbon (carbon is the principle alloying element) or alloy (in addition to carbon there are other alloying elements like Nb, V, W, Cr, Ni etc) steel. Plain carbon steels are the following types:

Properties

Low carbon

Medium carbon

High carbon

Carbon

Lower than 0.25 weight
Percent

In between 0.25 and 0.6 weight percent

In between 0.6 and 1.4 weight percent

Some
properties

Excellent ductility and
toughness.
Weldableand machinable
Not amenable to
Martensite transformation

Low hardenabilty.

These steel grades can be heat treated

Hardest,strongest and Least ductile

Some
applications

Common products like
Nuts, bolts, sheets etc.

 

For higher strength suchas in machinery,

Automobilesand agric-
cultural parts (gears,
axels,connecting rods)
etc.

Used where strength,hardness
and wear resistance
is required.
Cutting tools, cable,
Musical wires etc.

The alloy steels are classified as low (less than 5 weight% alloying elements), medium (in between 5 to 10 weight percent alloying elements) and high alloy steels (more than 10 weight percent alloying elements).