typical temperatures for workshop operations Temperature for Soldering brazing braze welding welding Hardening Tempering and forging ID: 229005
Download Presentation The PPT/PDF document "Identify" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Identify typical temperatures for workshop operations, Temperature for Soldering, brazing, braze welding, welding, Hardening, Tempering and forging.
4.3
Science
Prepared By:
Altaf
Hussain
Sajjad
AliSlide2
Process used to connect two materials
The connecting process is broadly known as welding. The welding can be performed only on metals and polymer materials.Slide3
Three processes used to connect two materials
SolderingBrazingWeldingSlide4
Soldering
Soldering is the process of joining two agents (Materials) using another jointing agentlead based jointing agent is used to join two agents. This process is take place in the temperature of about (?) 3000C to 4270CThe soldering agents have to be selected taking care not to damage the items to be joinedSlide5
Brazing
This is the process that is taking place at temperatures above (?) 4270CThen there is a requirement of the bonding agent having its melting point above this temperatureIn this process the widely used bonding agent is an alloy of copper in most cases brass alloys rather than bronzeThis process is useful to connect different kind of metals such as tool steel to mild steel, copper to steel etcSlide6
WeldingProcess of connecting two pieces of materials. Two pieces are heated to their melting points and allow to run together.
The required temperature is obtained in three forms namely induction heating, flame and arc.Induction heating is used to weld non-metallic materials as their melting points are comparatively low.Metallic materials as their melting points are very high flames and arcs are used as sources of heat.Slide7
Common type of flame used in welding is oxy-acetylene flame.The flame is having temperatures such as high as 32000C.In arc heating process the temperature is high as 35000C to 40000C and at this temperature the metals get white-hot and it gives a very bright light
WeldingSlide8
Heat treatmentAfter performing certain operations upon the metal it develop certain qualities that will make the piece of metal not very suitable for the operations that it intended to be used for. Such bad qualities are relieved from the work piece by
alloying it to undergo certain processes which use heat as the main treatment agent. These processes are called heat treatments. Slide9
Four major heat treatmentsAnnealingHardeningTempering
NormalizingSlide10
AnnealingThis is the process used to softening the metal. This process improves the machinability
of the metal piece.It releases the internal stresses in the metal.In this process three stages are presentHeating the metal piece to the required temperatureHolding the metal piece at that temperature for period long enough to relieve from the stresses.Cooling slowly to the room temperatureThe temperature used in this process is depend upon the composition of the metal. It ranges from 7600C for Tool Steel to 9250C for mild SteelSlide11
HardeningThis process is employed to hard the steel piece.Heating the piece to a temperature prescribed by the heat treatment graph depending to the carbon percentage of the steel plate.
then suddenly cooling it down to a low temperature well below the critical temperature.critical temperature is at about 7000C.Steel piece is cooled down to a temperature about 3000C.Slide12
TemperingThe process by which some hardness is removed but keeping the toughness is the tempering.
If the steel piece is hardened then it will improve the ductility of the material and it will become unsuitable to be used as a cutting tool which is the most frequently used application of steel in industry.Slide13
NormalizingThe term is often used for ferrous alloys that have been heated above the upper critical temperature and then cooled in open airSlide14
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging.
ForgingSlide15
Observing the colour
of the heated pieceColourTemperature
PurposeBlack Red4260C to 5380CTempering high speed steelVery Dark Red
593
0
C
Do -
Dark red
760
0
C
Hardening and annealing tool steel
Cherry red
815
0
C
Do -
Orange red
981
0
C
Hardening alloy tool steel
Yellow white
1259
0
C
Hardening high-speed steelSlide16