Metallurgy
INDUSTRIAL SHAPING OF METALS
Explain hot working processes. “It is process in which the metal is subjected to forces above recrystallisation temperature to give it a desired shape” OR “Hot working refers to processes where metals are plastically deformed above their recrystallization temperature”
It includes:
a. Rolling.
b. Forging.
c. Drop forging.
d. Heading. e. Hot pressing.
f. Extrusion
ADVANTAGES OF HOT WORKING PROCESSES
Advantages of hot working process (i)Due to refinements of grains, mechanical properties such as toughness, ductility, elongation and reduction in area are improved.
(ii) Great latitude in shape and size of farm is possible to reduction of elastic limit.
(iii) The power required to finish the part from ingot is less.
(iv) Directional property resulting from a fiber structure is obtained.
(v) The strength and hardness decreases at elevated temperature
DISADVANTAGES OF HOT WORKING PROCESSES
Disadvantages of hot working process
(i) The life of the tools used is less.
(ii) Tooling and handling costs are high.
(iii) Close tolerances cannot be maintained, oxide films are surface characteristics.
a: Rolling.
HOT ROLLING
Rolling is a fabricating process in which the metal, plastic, paper, glass, etc. is passed through a pair (or pairs) of rolls.
In metalworking, rolling is a metal forming process in which metal stock is passed through a pair of rolls If the temperature of the metal is above its recrystallization temperature, then the process is termed as hot rolling b. Forging.
Forging is a manufacturing process involving the shaping of metal using localized compressive force.
There are many different kinds of forging processes available, however they can be grouped into three main classes:[1] * Drawn out: length increases, cross-section decreases * Upset: length decreases, cross-section increases * Squeezed in closed compression dies: produces
Explain hot working processes. “It is process in which the metal is subjected to forces above recrystallisation temperature to give it a desired shape” OR “Hot working refers to processes where metals are plastically deformed above their recrystallization temperature”
It includes:
a. Rolling.
b. Forging.
c. Drop forging.
d. Heading. e. Hot pressing.
f. Extrusion
ADVANTAGES OF HOT WORKING PROCESSES
Advantages of hot working process (i)Due to refinements of grains, mechanical properties such as toughness, ductility, elongation and reduction in area are improved.
(ii) Great latitude in shape and size of farm is possible to reduction of elastic limit.
(iii) The power required to finish the part from ingot is less.
(iv) Directional property resulting from a fiber structure is obtained.
(v) The strength and hardness decreases at elevated temperature
DISADVANTAGES OF HOT WORKING PROCESSES
Disadvantages of hot working process
(i) The life of the tools used is less.
(ii) Tooling and handling costs are high.
(iii) Close tolerances cannot be maintained, oxide films are surface characteristics.
a: Rolling.
HOT ROLLING
Rolling is a fabricating process in which the metal, plastic, paper, glass, etc. is passed through a pair (or pairs) of rolls.
In metalworking, rolling is a metal forming process in which metal stock is passed through a pair of rolls If the temperature of the metal is above its recrystallization temperature, then the process is termed as hot rolling b. Forging.
Forging is a manufacturing process involving the shaping of metal using localized compressive force.
There are many different kinds of forging processes available, however they can be grouped into three main classes:[1] * Drawn out: length increases, cross-section decreases * Upset: length decreases, cross-section increases * Squeezed in closed compression dies: produces