2013-04-18

Susanna WeinbergerTechnical Manager Oerlikon Balzers Sandvik Coating AB

Press hardening

Austenitizing

Forming andQuenching Blanking

22MnB5

Ferrite-PerliteRm 600 MPa

MartensiteRm > 1500 MPa

Temperature difference Relative movement Al/Si-coating or oxide scales

Excessive wear

Press hardeningProcess challenges

Source: LFT Friedrich-Alexander University Nrnberg-Erlangen

OC Oerlikon Balzers AG

Press hardeningDirect process of uncoated sheet material

Page 3

Ploughing of tool surface by iron oxide particles

SEM picture of tempereduncoated steel sheet (22MnB5)

SEM picture of wornuncoated tool surface

Extreme abrasive wear at elevated temperature due

to ploughing of iron oxide

particles

Uncoated sheet after tempering

Big iron oxide wear particles (up to 2 m size)

Source: Rovalma

OC Oerlikon Balzers AG

Press hardeningDirect process of coated sheet material

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Less Ploughing of tool surface by Al-Si oxides

Cross section of AlSi coated steelsheet (USIBOR)

SEM picture of wornuncoated tool surface

Severe sticking of AlSi-coating on tool surface

little abrasive wear at elevated temperature

Coated sheet after heating at 950 C

Source: Rovalma

2m 2m

Material built up

Type of metal sheet

USIBOR (AlSi coated)

22MnB5 (uncoated)

Phs-ultraform (zinc coated) (1)

GammaProtect (zinc coated) (1)

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Abrasive/adhesive wear

Abrasive/adhesive wear

Extreme abrasive wear (3)

Adhesive wear (2)

Application problem

Sheet types in presshardening process

Press hardeningCoating selection

(2) Sticking of AlSi-coating on tool surface(3) Formation of scale on the sheet surface acts like a grinding powder

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BALINIT ALCRONA

BALINIT LUMENA

Solution

(4) For casted steel tools or big tool dimension

(1) Phs-ultraform indirect process, GammaProtect direct process

Important coating properties

Friction coefficient

Oxidation resistance

Residual stress

Hardness/Ductility

Hot hardnessChemical

stability against the workpiece

material

Thermophysical properties

Abrasive wear resistance

OC Oerlikon Balzers AG

Coating propertiesAbrasive wear resistance at elevated temperatures

Clear benefit of AlCrN (ALCRONA) compared to TiAlN (LUMENA)

20C

500C

700C

20C

500C

700C

(AlCrN) ALCRONA (TiAlN) LUMENA

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200

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500

600

700

800

900

550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200

Comparison with titanium-based coatings

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Oxidation temperature [C]

Completely oxidised

BALINIT B BALINIT LUMENA

BALINIT X.CEED

Holding time hour in ambient atmoshpere

BALINIT ALCRONAOxidation resistance

BALINIT ALCRONA

Nakajima test with BALINIT ALCRONA coated punch

Friction behaviourNakajima test

Source: LFT Friedrich-Alexander University Nrnberg-Erlangen

Test condition

Sheet metal Arcelor USIBOR

Sheet temperature 900C

Heating duration 10 min

Tool temperature 620C

Punch radius 50 mm

Test device

0

10

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60

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0 10 20 30 40 50 60distance [mm]

p

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ALCRONA coated 1st testALCRONA coated 2nd testuncoated 1st testuncoated 2nd test

mm

Improved friction conditions yield in a more homogeneous forming process

BALINIT treatment benefits

BALINIT treatment benefits

Tool lifetime extended for around 100% in some cases (especially bumper tools) up to 200%

Added benefits:

No repair welding necessary Less maintenance Less press downtime due to reduced

cleaning cycles (for USIBOR material)

coated tools:- bumper - door beam- B-pillar- roof rail- sill

Application examples BALINIT ALCRONAUncoated steel sheet

Coating thickness : > 8

Application examples BALINIT LUMENACoated steel sheet

Bumper tool Roof rail

Application examples BALINIT LUMENACoated steel sheet

B-pillar

Werkzeug Sule B Limo/AvantApplication examples PPDCoated steel sheet

B-pillar PPD process picture

Detailed App Description Automotive Hot Stamping

Type of produced part B Pillar

Application Problem Scale formation it should be

Type of metal sheet Uncoated sheet

Tool steel H13

Coating type BALINIT ALCRONA DUPLEX

Pre-Post treatments Pre and Post Polish

FEEDBACK

Application result Over 500k hits to date.

Additional Feedback Tool Failure with no coating at 200k

Application examples BALINIT ALCRONAuncoated steel sheet

Thank you

Oerlikon Balzersclose to youanywhere in the world