ADI JS/800-10 in substitution of Nitrided EN-GJS 700-2 for ... · ADI DAYS 2016 6th –7th October...

Austempering, A Technology for Substitution

ADI DAYS 2016 6th – 7th October Minerbe

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ADI JS/800-10 in substitutionof Nitrided EN-GJS 700-2 forprecision Planetary Gearbox

Dr.-Ing.Franco Concli

[email protected]

ADI JS/800-10 in substitution of Nitrided EN-GJS 700-2 for precision Planetary Gearbox



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Ring gear

Centering (Output)Output flange

Bearing seat




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EN 1563:2011 𝑹𝑴 [MPa] 𝑹𝑺 [MPa] A% [-] HV

EN-GJS-700-2 700 420 2 284-237

EN-GJS-700-2 Nit-Ox 700* 420* 2 450-520

Casting Rough machining Broaching Heat treatment Finishing

HV>450




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EN 1564:1997 𝑹𝑴 [MPa] 𝑹𝑺 [MPa] A% [-] HV

EN-GJS-800-8 800 500 8 260-320

EN-GJS-1000-5 1000 700 5 300-380

EN-GJS-1200-2 1200 850 2 340-440

EN-GJS-1400-1 1400 1100 1 380-480

Casting Rough machining Broaching Finishing




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Hub

Tooth

Root

Tip

Rounding(trochoid)

Tip circle

Root circle

Flank(circle evolvent)




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Failure Type Effect

Bending Fatigue Catastrophic

Pitting Chafing fatigue Acceptable ?

Micropitting Chafing fatigue Acceptable ?

Scuffing Local welding (failure of the lubricant) Progressive damaging




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Failure

Bending

Pitting

Micropitting

Scuffing




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Failure

Bending

Pitting

Micropitting

Scuffing




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Failure

Bending

Pitting

Micropitting

Scuffing




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Failure

Bending

Pitting

Micropitting

Scuffing




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Calculation of tooth bending strength

FN

2

cos6

1

cos

Fn

anFabnf

MAX

Sb

hF

W

M




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FPF

XlTRlT

F

NTSTFFP YYY

s

YY

ReRe

min

lim

Tooth root stress Permissibile bending stress

FFVA

n

tSaFaF KKKK

mb

FYYY




FPF

FFVA

n

tSaFaF KKKK

mb

FYYY

XlTRlT

F

NTSTFFP YYY

s

YY

ReRe

min

lim

Tooth form factor(outer point of single contact)

Stress correction factor(notches)

Helix angle factor Application factor

Dynamic factor (tollerances)

Load factors(uneven load distribution)


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FPF

XlTRlT

F

NTSTFFP YYY

s

YY

ReRe

min

lim

Life factorStress correction factor = 2

Sensitivity factors

Size factor


FFVA

n

tSaFaF KKKK

mb

FYYY




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Nominal stress EXPERIMENTAL

FPF

XlTRlT

F

NTSTFFP YYY

s

YY

ReRe

min

lim


FFVA

n

tSaFaF KKKK

mb

FYYY




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Calculation of surface durability

u

u

db

F

EE

p tH

1

cossin

2

11

1

1

2

2

2

1

2

1




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HPH

HHVAt

EHH KKKKu

u

db

FZZZZ

1

1

XWVRL

H

NHHP ZZZZZ

s

Z

min

lim

Contact stress Permissibile contact stress




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HPH

HHVAt

EHH KKKKu

u

db

FZZZZ

1

1

XWVRL

H

NHHP ZZZZZ

s

Z

min

lim

Contact ratio factor

Helix angle factor Application factor

Dynamic factor (tollerances)

Load factors(uneven load distribution)

Elasticity factor

Zona factor(Herzian pressure)





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HPH

HHVAt

EHH KKKKu

u

db

FZZZZ

1

1

XWVRL

H

NHHP ZZZZZ

s

Z

min

lim

Roughness factorLife factor

Velocity factor

Size factor

Work hardening factor

Lubricant factor





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HPH

HHVAt

EHH KKKKu

u

db

FZZZZ

1

1

XWVRL

H

NHHP ZZZZZ

s

Z

min

lim

Allowable stress number EXPERIMENTAL





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Toot bending strength characterization

F ⊥ flank: property of the circle evolvent

t

F R=0.1

W3




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Fixed part

Moving part

Movingpunch

Fixedpunch

Pin: centering

W3




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42

44

46

48

50

1 2 3 4 5 6

F [

kN

]

Test No [\]

Results of the Bending Test - ADI grade JS 800-10

Failure RunOut

Dixxon




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Surface durability characterization

Motor

Actuator

Slave gearbox Gears on test




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Surface durability characterization

1,0E+04 1,0E+05 1,0E+06 1,0E+07 1,0E+08 1,0E+09

N1 (-)

Results of Pitting Test - ADI grade JS 800-10

FailureRunout50% failure probability10% failure probability90% failure probabilityAGMA 939-A07 for HBW 310AGMA 939-A07 for HBW 250

Running in Test

T1 (Nm) 100 200-280

w (rpm) 1500 3000

q (°C) 60 60




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Conclusions

Experimental test were preformed on ADI JS/800-10 gear samples.

ADI JS/800-10 results comparable in terms of tooth root bending strength as well as surface durability withthe EN-GJS 700-2 nitrided cast iron and suitable for gear applications.

The low distortion induced by the austempering treatment, allows to reduce or avoid a further machining.

Eventual finishing operations are made on a low-hardness material: this implys faster and cheaperoperations

ADI JS/800-10 in substitution of Nitrided EN-GJS 700-2 for ... · ADI DAYS 2016 6th –7th October...

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Transcript of ADI JS/800-10 in substitution of Nitrided EN-GJS 700-2 for ... · ADI DAYS 2016 6th –7th October...