Advanced Plastic Mold Steel

Notes about safety

Printed in June 2016Catalog No.: HL-Y70 (PDF)

• The charactersitics and properties listed on this catalogue are representative and not guaranteed values.

• This catalog and its contents are subject to change without notice.

• Do not duplicate or reprint all or any part of this catalogue without prior permission from Hitachi Metals, Ltd.

• Please contact representatives of our Specialty Steel Division at the locations listed below for any inquiries.

Our address and contact indicated in this catalogare those as of June 2016.If you cannot put a call through, please contactbelow.

Hitachi Metals, Ltd.Toll-free 0800-500-5055 (in Japan)Tel: +81-3-6774-3001

Steel is heavy. Please execute the safety measures to prevent falling or collapse of cargo or sandwiched during transportation or warehousing. Please ensure the safety of workers use the jigs and various protective equipment and follow the applicable laws and ministerial ordinance, ordinances, guidelines, etc. when sawing, cutting, heat treatment, polishing or when using as mould, machine parts, or tooling.

CENA, CENA1, HI-PM and YSS are trademarks of Hitachi Metals, Ltd.

Shinagawa Season Terrace, 1-2-70, Konan, Minato-ku,Tokyo 108-8224, Japan High-Grade Metals Company, Tool Steel Business Unit

Head Office

Cha Shan Town, Dong Guan City, 522380, China

Head Office

Head Office

Tel. +86-769-8640-6726

3#-2, Koushin Mould Industrial Park Ⅲ B-1-1-1F.T. Z. Dalian, 116600, China

Dalian Branch Tel. +86-411-8718-1011/1022

No.69 Shuang Ying Road, Qingpu Industrial Zone, Qingpu District, Shanghai, 201712, China

Shanghai Branch Tel. +86-21-3929-2202

No.11, Jianshe 4th Branch Road, Balitai Town, Jinnan District,Tianjin, 300350, China

Tianjin Jinnan Branch

Tel. +86-22-8699-3101/3102

12 Gul Avenue, Singapore 629656 Tel. +65-6861-7711

Immermannstrasse 14-16, 40210 Duesseldorf, Germany

Head Office

Head Office

Chicago, Detroit, Pittsburgh, San JoseOther Office

London, Milano, ParisOther Office

333, Gongdan 3-daero, Siheung-si, Gyeonggi-do, 15115, KoreaRm.1606. City Air Tower Bldg., 36.Teheran-ro 87-gil, Gangnam-gu, Soeul, 06164, Korea20, Hwajeonsandan 6-ro 102beon-gilGangseo-gu, Busan 46738, Korea

Soeul Branch

Busan Branch

2 Manhattanville Road, Suite 301,Purchase, NY 10577, U.S.A.

Tel. +49-211-16009-0

Tel. +1-914-694-9200

Tel. +81-3-6774-3320

Tel. +82-31-319-3933

Tel. +82-2-551-4422

Tel. +82-51-941-3933

http://www.hitachi-metals.co.jp/e

40 HRC Prehardened Grade Steel

This steel contributes to total cost reduction with good rust resistivity and

excellent mirror polishability.

Catalog

2 3

CENA1(37-42 HRC)

P21 conventional steel

(40 HRC)

HI-PM 7(29-33 HRC)

CENA-V(35-41HRC)

Mirror Polishability Good

Rus

t R

esis

tivity

Goo

d

CENA1(37-42 HRC)

P21 conventional steel

(40 HRC)

HI-PM 7(29-33 HRC)

CENA-V(35-41 HRC)

Thermal Conductivity Good

Toug

hnes

sG

ood

Item CENA-V CENA1 P21 conventional steel HI-PM 7

DurabilityHardness (HRC) 35-41 37-42 37-43 29-33

Toughness A C D A

Rust Resistivity A A D D

Mirror Polishability A A A D

Weldability A B D A

Thermal Conductivity B C B A

MachinabilityProfiling B B B A

Hole processing C C B A

Use Conventional Properties of Evaluation Appearance

Automotive lamp parts

P21 conventional steel

(40 HRC)

• Polishability

• Rust resistivity

• Applicable for large size mold

Bathroom fixtures

P21 conventional steel

(40 HRC)

• Polishability

• Rust resistivity

• Applicable for large size mold

Home appliances

CENA1(40 HRC)

• Polishability

• Rust resistivity

• Applicable for High-speed heat cycle molding

Home appliances

P21 conventional steel

(40 HRC)

• Polishability

• Toughness

This steel contributes to total cost reduction with good rust resistivity and excellent mirror polishability.

The plastic mold steel, CENA-V, was created to satisfy mold

makers and resin product manufacturers. Its properties will

reduce maintenance man-hours and prevent issues during

mold manufacturing.

excellent “A”←→ poor “D”

■ Characteristics Comparison

■ Rust Resistivity and Mirror Polishability ■ Toughness and Thermal Conductivity

■ Examples for ApplicationThis mold steel can be utilized in a variety of applications, including home appliances, automotive parts, and bathroom fixtures.

Contributive to productivity and total cost reduction*Comparison with P21 conventional steel (Hitachi Metals product name: HI-PM-PRO)

Nitriding PropertyGood Texturing Processability

Excellent Mirror PolishabilityRust Resistivity

Good WeldabilityGood Thermal Conductivity

Features of CENA-V

Advanced Plastic Mold Steel

4 5<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

These comments are customers impression and does not guarantee the performance of product.

Test piece

3.5% salt water

1 10 100 1000

HI-PM 38* 49 HRC(350°C Tempering)

no crack occur

*JIS-SUS420J2 improvement steel.

CENA1

CENA-V

Test time until craking (Hr)

Str

ess

(MP

a)

200

0

400

600

800

1000

1200

1400

Resistance to Stress Corrosion Cracking

Rust Resistivity of Polished Surface (step 1)[Condition ] Finished by #8,000 emery paper, Temperature: 24-26 degrees Celsius. Humidity: 39-41 percent. 3 hours hold.

Rust Resistivity of Polished Surface (step 2)[Polishing method ] Removed by diamond abradant (1st, 6 micrometer single-crystal, 2nd, 3 micrometer polycrystal.)

Evaluation result

(after 8 min. polishing)

CENA-V

Removable by diamond polishing.

(after 8 min. polishing)

CENA 1

Removable by diamond polishing.

(after 8 min. polishing)

P21 conventional

steel

Not removable by diamond polishing; re-polish with emery paper required.

(after 13 min. polishing)

CENA-V has high toughness and good cracking resistance which give it good weldability.

CENA-V is a good choice for food container molds because of its resistance to rusting.

CENA-V is easy to polish and has a glossy finish after polishing.

CENA-V is less prone to clogging of water cooling holes.

CENA-V is suitable for exported molds thanks to its rust resistance.

Cavity sections in CENA-V blocks are easier to maintain because of its rust resistivity.

The process of surface texturing can be done more efficiently on CENA-V due to its resistance to rust.

CENA-V’s resistance to rust allows for smaller quantities of anti-rust oil to be needed.

CENA-V has good resistance to rusting and may be wire cut.

CENA-V’s high toughness results in less breakage of thin ribs during machining.

CENA-V can be used for slide cores because surface hardness after nitriding is over 1000HV.

CENA-V molds can be produced in locations near the sea-side without concerns of corrosion.

Toughness… ……………………………… p. 9

Rust Resistivity… ………………………… p. 5

Texturing Processability… ……………… p. 6

Rust Resistivity… ………………………… p. 5

Rust Resistivity… ………………………… p. 5

Rust Resistivity… ………………………… p. 5

Rust Resistivity… ………………………… p. 5

Rust Resistivity… ………………………… p. 5

Rust Resistivity… ………………………… p. 5

Toughness… ……………………………… p. 9

Texturing Processability… ……………… p. 6

CENA-V exhibits an even surface texture with good rust resistance.

Toughness… ……………………………… p. 9

Rust Resistivity… ………………………… p. 5

CENA-V has given us more freedom in designing integrated molds, because thick sections are available.

Examples for Application………………… p. 3

CENA-V has improved rust resistivity compared to conventional pre-hardened P21.

CENA-V has improved stress corrosion cracking resistance compared to SUS420J2 improvement steel.

Punctated rust has occurred. Punctated rust became pinhole.

2 mm

2 mm

2 mm

2 mm

2 mm

2 mm

Die makers and surface treaters had the following comments:

Mold Manufacturers had the following comments:

Customer Feedback on the Performance of CENA-V

Interference figure comparison of mirror polished surface

[ Testing Condition ]

Constant Load Type Test Apparatus for Stress Corrosion Cracking

Rust Resistivity

6 7<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

CENA-V CENA1 P21 conventional steel

3μmdiamond polishing(#8000)

B. Polishing loads should be kept as low as possible.C. Foregoing polish should be done prudently.D. Rust proof measures must be taken in any interruption of jobs.

Remarks:A. Use a diamond compound over alumina and chromium oxide.

Scratch remains due to overload.

Seam and pinhole texture at crossing by less foregoing polish

Pinhole texture by poor rust-proo�ng.

Diamond Compound Finish Aluminium Oxide Finish Not Good

Chromium Oxide Finish Not Good

A

B C D

Texturing Processability

Mirror Polishability

■ Polish by oil grinding stone (use an oil-based coolant)#400→#600→#1000→#1500→#3000

■ Polish by coated abrasive (Dry process)#1500→#2000→#2500

■ Finish polishing by diamond paste#1500 (9 μm)→#3000 (6 μm)→#8000 (3 μm)

Point 1 When changing numbers, check if any scratches remain by rotating the polishing direction (45-90 degrees).

Point 2 Check for remaining scratches by illuminating the polished surface and inspecting in multiple directions.

Point 3 When changing numbers, wash and remove all polishing grains.

Point 4 When using an oil whetstone, apply sufficient oil to prevent scratching.

Point 5 When using sandpaper, polish 10-15 times at once to prevent orange peel or clogging.

Point 6 Polishing with a diamond compound needs to be performed in short intervals. Excessive polish can produce pinholes or orange peel.

Point 7 For maximum polishing capability, use a diamond compound over alumina and chromium oxide.

Point 8 Protect the metal from rust during long interruptions in the polishing process.

Polishing Procedure

[ Texturing example ]

Pear skin Finish Grain Leather Pattern

Carbon Fiber PatternDot Pattern

2 mm 2 mm 2 mm

10 mm

10 mm

10 mm

10 mm

<Attention>Mirror polished surfaces above #5000 will strongly depend on skill level.Quality of Mirror surface may be worsened by the polishing skill level.

CENA-V’s homogenized microstructure provides good Texturing Processability.

CENA-V’s low inclusion content provides excellent Mirror Polishability.

Examples Interference figure comparison of #8000 mirror polished surface.

Key Points of Polishing Procedure (by our knowledge)

8 9<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

0

0.5

1.0

1.5

CENA-V37 HRC

P21 conventional steel40 HRC

Wei

ght

red

uctio

n ra

te (%

)

CENA-V37 HRC

P21 conventional steel40 HRC

0

20

40

60

80

Sp

eci�

c ab

rasi

on v

olum

e((m

m3 /

mm

2 ・m

m)×

10-7)

CENA-V CENA1 P21conventional steel HI-PM 7

0

50

100

150

Cha

rpy

imp

act

valu

e(In

dex

)

Elo

ngat

ion,

Red

uctio

n of

Are

a (%

)

: Elongation: Reduction of

area

CENA-V37 HRC

CENA140 HRC

P21 conventional steel40 HRC

0

10

20

30

40

50

60

Tens

ile S

tren

gth

and

0.2

%Y

ield

Str

engt

h (M

Pa)

: 0.2%Yield Strength : Tensile Strength

800

900

1000

1100

1200

1300

CENA-V37 HRC

CENA140 HRC

P21 conventional steel40 HRC

Welding condition Welding procedure diagram

●TIG WeldingRod　　　　　　　Currentφ2.4 ･･････････80–160 Aφ3.2 ･････････110–200 A

Flow Rate 10–15 ℓ/min

Pre-heat150–300°C

Post-heat150–300°CCool Slowly

Air Cooling

Welding450°C–520°C

(Stress relie�ng for correctingdeformations and precise texturing)

[ Test condition ]

Slurry: Al2O3 (mean dia 346 μm)1,000 g H2O 700 cc

Friction rotation speed: 870 rpm

Friction time: 20 h

[Test condition ]

Work material: SCM415

Friction speed: 0.79 m/s

Load: 67 N

Friction distance: 400 m

Test piece

Slurry

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Distance from surface (mm)

P21 conventional steel

CENA-V

Har

dne

ss (H

V)

200

400

600

800

1000

1200

■Hardness profile of gas soft nitriding cross section (example)

Slurry Wear Test Ohgoshi-method Wear Test

Nitrided surface microstructure (example)

200 μm

CENA-V is more resistant to corrosion from reinforced resin.

CENA-V is more resistant to abrasion caused by sliding friction.

Test piece

Work material

Nitriding

Nitriding can increase surface hardness up to 1000 HV, useful for sliding applications.

Toughness

High impact toughness in comparison to conventional P21 makes CENA-V difficult to fracture.

Strength Properties

CENA-V has high percent elongation and reduction of area in comparison to conventional P21

Weldability

High toughness improves crack resistance from welding build-up.

Wear Resistance

Hardness is lower than conventional P21, with equal or higher wear resistance.

<Attention> Recommended nitriding temperature is 520 degrees centigrade or under.

<Attention> ・Welding rod recommends materials of similar chemical composition as mold. ・Pre-heat and Post-heat are recommended to prevent mold cracking. ・Stress reliefing is recommended to prevent uneven polishing and texturing.

10 11<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

<Attention> The characteristics, photos, charts, rankings and evaluations of this catalog are representative value by our test data, it does not guarantee the quality of the product. This catalog and its contents are subject to change without notice.

CENA-V P21 conventional steel

MaterialThermal expansion coefficient (x10-6/˚C) Thermal conductivity W/(m･K) Young’s

modules(GPa)100˚C 200˚C 20˚C (RT) 100˚C 200˚C

CENA-V 10.6 11.5 31.2 33.6 34.7 208

CENA 1 10.8 11.5 20.5 22.9 25.9 205

P21 conventional steel 12.5 12.8 28.5 32.6 36.4 200

0.1

0.2

0.3

0.4

0 20 40 60

P21 conventional steel

(Outbreak of chipping)

Flan

k w

ear (m

m)

Cutting length (m)

CENA-V

P21 conventional steel

50 100 150 200 250 300

Flan

k w

ear (m

m)

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

Cutting length (m)

CENA-V

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 500 1000

Flan

k w

ear (m

m)

Number of drilling holes

CENA-V

P21 conventional steel

Diam.

Recommendation

spindle speed(min-1)

feed (mm/min) cutting speed(m/min)

feed(mm/rev)

Intersect straight

φ 6.0 1,060 7 10.6 20 0.01

φ 8.0 1,000 7 10.0 25 0.01

φ10.0 950 10 14.0 30 0.015

φ14.0 680 7 10.2 30 0.015

φ18.0 530 7 10.6 30 0.020

φ 20.0 560 10 14.0 35 0.025

φ 22.0 500 8 12.5 35 0.025

Diam.spindle speed(min-1)

feed(mm/min)

cutting speed (m/min)

feed(mm/rev)

φ 4.0 800 40 12 0.050

φ 6.0 530 30 10 0.056

φ 8.0 400 32 10 0.080

φ10.0 320 26 10 0.080

φ12.0 270 22 10 0.080

φ15.0 210 21 10 0.100

φ 20.0 160 19 10 0.119

φ 30.0 110 16 10 0.145

[Tool ] ASRT5063R-4 (Mitsubishi Hitachi Tool Eng.)

[ Insert ] WDNT140520 JP4120

[ Size ] Φ63 mm, 4-flute

[Cutting conditions ]

・Spindle speed: n = 600 m/min-1

・Cuttin speed: Vc = 118 m/min

・Feed speed: Vf = 4800 mm/min

・Feed per tooth: fz = 2.0 mm/t

・Cutting depth: ap = 0.85 mm

・Overhang length: 100 mm

・Cutting fluid: Air blow

[Tool ] Coated carbide ball end mill (R5×2-flute)

[Cutting conditions ]

・Spindle speed: n = 10,000 min-1

・Feed speed: Vf = 2,000 mm/min

・Cutting depth: ap = 1.0 mm

・Cutting width: ae = 1.0 mm

・Cutting fluid: Air blow

CENA-V P21 conventional steel

[ Tool ] 05WHNSB0450-TH (Cemented carbide drill) (Mitsubishi Hitachi Tool Eng.) (Φ4.5 mm, Flute length 47 mm)

[Hold depth] H = 22 mm

[Size ] Φ63 mm, 4-flute

[Cutting conditions ]

・Spindle speed: n = 4250 m/min-1

・Cuttin speed: Vc = 60 m/min

・Feed speed: Vf = 510 mm/min

・Feed per tooth: fz = 0.12 mm/rev

・Non step

・Water-soluble cutting fluid internal lubricating oil-hole

Material: JIS-SKH51Material: Generai-purpose cemented carbide gun drill

At hole intersection, please reduce feed speed to half of straight to pre-vent damage by chipping.

In case hole-depth exceed 5D, please step drilling.Plenty of cutting fluid lubricate is recommended.

Recommended cutting conditions

Machinability

Processing Machinability of high-feed cutting radius mill is better than conventional P21.

Finish processing Finish processing by coated carbide end mill is comparable to conventional P21. Ball end mill edge wear is equal or worse than conventional P21.

Drilling processing The tool wear is worse than conventional P21.

Physical Properties

CENA-V’s high thermal conductivity is comparable to conventional P21.

<Attention>Transformation may occur after rough processing depending on size and the shape of the die.Camber relief processing is recommended before finishing.

Chip separation may be difficult due to high toughness. Hole drilling is advisable to about 70-85 percent compared to conven-tional P21.

■Wear comparisons: After drilling 1000 times

■ Gun drill processing conditions ■ HSS drill processing conditions