Martempering and Austempering Final Slide

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MARTEMPERING AND  AUSTEMPERING

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STEELS

•can be heat treated to highhardness and strength levels for

getting the required strength forvarious applications.

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• Structural componentssubjected to high operating

stress need the highstrength of a hardenedstructure.

STEELS

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• tools such as dies, knives,cutting devices, and

forming devices need ahardened structure toresist wear and

STEELS

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• Quenched hardened steelsare so brittle that even slight

impacts may cause fracture

STEELS

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• “TEMPERING” to removethe stresses and

brittleness caused byquenching and to develop

the required mechanical

STEELS

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TEMPERING

• a heat treatment thatreduces the brittleness

of steel withoutsignicantly lowering itshardness and strength.

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• !ll hardened steels must

undergone this treatmentbefore use.

TEMPERING

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•  Processes:

". #artempering

$. !ustempering%. &onventional 'eat,

Quench and (emper

TEMPERING

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• )#arquenching* is a form of heattreatment applied as aninterrupted quench of steels

typically in a molten salt bath at atemperature right above themartensite start temperature.

MARTEMPERING

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• to delay the cooling for alength of time to equali+e the

temperature throughout thepiece which will minimi+edistortion, cracking and

residual stress.

MARTEMPERING

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--/0(S1• 2educed cracking due to thermal

stress.

• 2educed residual stress in thequenched part section for parts

with varying geometry, si+e, or

MARTEMPERING

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• Since marquenching lowersthe residual thermal stress, it

is used for parts with comple3geometries, diverse weights,and section changes.

MARTEMPERING

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MARTEMPERING

• Quenchingfrom theaustenitising

temperatureto atemperatureabove themartensitic

425&-SS

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MARTEMPERING

• 'olding in the

quenchingmedium untilthe

temperaturethroughoutthe steel issubstantiallyuniform

425&-SS

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MARTEMPERING

•

&ooling at amoderaterate toprevent large

di6erencesbetween theoutside and

the centre of

425&-SS

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MARTEMPERING

•  (emperinginconventional

fashion

425&-SS

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 AUSTEMPERING

•  is a heat treating process formedium8to8high carbon ferrousmetals which produces !00(-structure.

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0t yields desirable mechanicalproperties including1

• 'igher ductility, toughness, and

strength for a given hardness.• 2esistance to shock

• 2educed distortion, specically

with thin parts.

 AUSTEMPERING

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•

 (his process is widely used inthe automotive industry forclips and other parts where

ma3imum 9e3ibility andtoughness are required.

 AUSTEMPERING

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 AUSTEMPERING425&-SS

• 'eating to

atemperature within

theaustenitising range,

usually

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• Quenched in a

bath )moltensalt, oroccasionally oil*maintained at a

constanttemperature,usually in the

range of $@<=8

%:<=& )><<8=

 AUSTEMPERING425&-SS

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•'eld for atime to allowtransformationto a bainitemicrostructure

 AUSTEMPERING425&-SS

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•

&ooled toroomtemperature.

 AUSTEMPERING425&-SS

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MANA