UDDEHOLMUNIMAX

UNIMAX

2

UNIMAX

REFERENCE STANDARD

AISI WNr. JIS

ASSAB DF-2 ARNE O1 (1.2510) (SKS 3)

ASSAB DF-3 O1 (1.2510) (SKS 3)

ASSAB XW-5 SVERKER 3 D6 (D3) (1.2436) (SKD 2)

ASSAB XW-10 RIGOR A2 1.2363 SKD 12

ASSAB XW-41 SVERKER 21 D2 1.2379 SKD 11

ASSAB XW-42 D2 1.2379 SKD 11

CARMO CARMO 1.2358

CALMAX CALMAX 1.2358

CALDIE CALDIE

ASSAB 88 SLEIPNER

ASSAB PM 23 SUPERCLEAN VANADIS 23 SUPERCLEAN (M3:2) 1.3395 SKH 53

ASSAB PM 30 SUPERCLEAN VANADIS 30 SUPERCLEAN (M3:2 + Co) 1.3294 SKH 40

ASSAB PM 60 SUPERCLEAN VANADIS 60 SUPERCLEAN (1.3292)

VANADIS 4 EXTRA SUPERCLEAN VANADIS 4 EXTRA SUPERCLEAN

VANADIS 6 SUPERCLEAN VANADIS 6 SUPERCLEAN

VANADIS 10 SUPERCLEAN VANADIS 10 SUPERCLEAN

VANCRON 40 SUPERCLEAN VANCRON 40 SUPERCLEAN

ELMAX SUPERCLEAN ELMAX SUPERCLEAN

ASSAB 518 P20 1.2311

ASSAB 618 P20 Mod. 1.2738

ASSAB 618 HH P20 Mod. 1.2738

ASSAB 618 T P20 Mod. 1.2738 Mod.

ASSAB 718 SUPREME IMPAX SUPREME P20 Mod. 1.2738

ASSAB 718 HH IMPAX HH P20 Mod. 1.2738

NIMAX NIMAX

MIRRAX 40 MIRRAX 40 420 Mod.

VIDAR 1 ESR VIDAR 1 ESR H11 1.2343 SKD 6

UNIMAX UNIMAX

CORRAX CORRAX

ASSAB 2083 420 1.2083 SUS 420J2

STAVAX ESR STAVAX ESR 420 Mod. 1.2083 ESR SUS 420J2

MIRRAX ESR MIRRAX ESR 420 Mod.

POLMAX POLMAX

RAMAX HH RAMAX HH 420 F Mod.

ROYALLOY ROYALLOY

PRODAX

ASSAB MM40

ALVAR 14 ALVAR 14 1.2714 SKT 4

ASSAB 2714 1.2714 SKT 4

ASSAB 8407 2M ORVAR 2M H13 1.2344 SKD 61

ASSAB 8407 SUPREME ORVAR SUPREME H13 Premium 1.2344 ESR SKD 61

DIEVAR DIEVAR

HOTVAR HOTVAR

QRO 90 SUPREME QRO 90 SUPREME

ASSAB 705 4340 1.6582 SNCM8

ASSAB 709 4140 1.7225 SCM4

ASSAB 760 1050 1.1730 S50C

ASSAB is a trademark of ASSAB Pacific Pte Ltd.

The information contained herein is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should not therefore be construed as a warranty of specific properties of the products described or a warranty for fitness for a particular purpose. Each user of ASSAB products is responsible for making its own determination as to the suitability of ASSAB products and services.

Edition D140714

3

UNIMAX

General

Unimax is a chromium-molybdenum-vanadium alloyed tool steel which is characterised by:

Excellent toughness and ductility in all directions Good wear resistance Good dimensional stability during heat treatment Excellent through-hardening properties Good resistance to tempering back Good hot strength Good thermal fatigue resistance Excellent polishability

ApplicationsUnimax is suitable for long run production moulds, moulds for reinforced plastics and compression moulding.

Unimax is a problem solver in severe cold work tooling applications, such as heavy duty blanking, cold forging and thread rolling, where high chipping resistance is required.

Engineering and hot work applications requiring high hardness and toughness are also applications where Unimax has proven to be successful.

PropertiesThe properties below are representative of samples which have been taken from the centre of bars with dimensions 396 x 136 mm, Ø 125 mm and Ø 220 mm. Unless otherwise indicated, all specimens have been hardened at 1025°C, gas quenched in a vacuum furnace and tempered twice at 525°C for two hours to 56–58 HRC.

MECHANICAL PROPERTIES

Approximate strength and ductility at room temperature at tensile testing.

Rotor for an electric motor, moulded in Unimax.

Hardness 54 HRC 56 HRC 58 HRC

Yield strength, Rp0.2

1720 MPa 1780 MPa 1780 MPa

Tensile strength, Rm

2050 MPa 2150 MPa 2510 MPa

Elongation, A5 9 % 8 % 8 %

Reduction of area, Z

40 % 32 % 28 %

Typical analysis %C

0.5Si

0.2Mn 0.5

Cr 5.0

Mo 2.3

V 0.5

Standard specification

None

Delivery condition Soft annealed to approx. 185 HB

Colour code Brown / Grey

PHYSICAL PROPERTIES

Hardened and tempered to 56 - 58 HRC.

Temperature 20°C 200°C 400°C

Density kg/m3 7 790 - -

Modulus of elasticity MPa

213 000 192 000 180 000

Coefficient of thermal expansion per °C from 20°C

- 11.5 x 10-6 12.3 x 10-6

Thermal conductivity W/m °C

- 25 28

Specific heat J/kg °C

460 - -

Approximate strength at elevated temperatures

Longitudinal direction. The specimens were hardened from 1025°C and tempered twice at 525°C to 58 HRC.

800

1000

1200

1400

1600

1800

2000

2200

2400

Stress, MPa

0 100 200 300 400 500 600°C

Testing temperature

Rp0.2

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UNIMAX

1 100Time, h

550°C

Hardness, HRC60

55

50

45

40

35

30

25

600°C

650°C

10

Impact energy, KV, J 35

30

25

20

15

10

5

0

Longitudinal

Short transverse

-100 0 100 200 300 400

Testing temperature

500°C

1000 200 300 400 500 600°C

Testing temperature

Rm

Stress , MPa

2400

2200

2000

1800

1600

1400

1200

1000

800

Rp0.22

25

20

15

65

64

63

62

61

60

Grain size

ASTM Hardness, HRC

Hardness

Grain size

Retained austenite

990 1000 1020 10301010 1040 1050°C

25

20

15

10

5

Austenitising temperature TA, 30 minutes

520 540 560 580

Retained austenite, %

Retained austenite, %

35

30

25

20

15

10

5

Hardness, HRC60

58

56

54

52

50

48

46

TA=1025°C Hardness

500

Tempering temperature (2 x 2h)

TA=1000°C Hardness

=1025°C Retained austeniteTA

600°C

Dimensional changes, %0.16

0.12

0.08

0.04

0.00

-0.04500 520 540 560 580 600°C

1020°C Transverse

1020°C Short Transverse

1020°C Longitudinal

Tempering temperature (2 x 2h)

MS

Austenitising temp. 1025°CHolding time 30 minutes

1100ºC

1000

800

700

600

500

300

200

100

400

900

CarbidesPearlite

101 100 1000 10 000 100 000

1 10 100 1000

Seconds

Minutes

Hours

Air cooling ofbars, Ø mm

0.2 1.5 10 90 600

1 10 100

Bainite

Martensite

321 4 5 6 8 97

Mf

ACs

= 820ºC

ACf

= 880ºC

1

98765432

835819798782724712674525476

1533

140630106429006250

13850

CoolingCurve No.

HardnessHV 10

T800-500

(sec)

Effect of testing temperature on impact energy

Charpy-V specimens, longitudinal and short transverse directions. Approximate values for specimens taken from Ø 125 mm bar.

Unimax is a solution to deformed or cracked shear blade for cutting warm steel.

CCT graph

Austenitising temperature 1025°C. Holding time 30 minutes.

25

30

35

40

45

50

55

60

Hardness, HRC

550°C

600°C

650°C

1 10 100

Time, h

500°C4003002001000-1000

5

10

15

20

25

30

35

Impact energy, KV, J

Testing temperature

Effect of time at high temperatures on hardness

Initial hardness 57 HRC

5

UNIMAX

TEMPERING

Choose the tempering temperature according to the hardness required by reference to the tempering graph below. Temper at least twice with intermittent cooling to room temperature.

The lowest tempering temperature which should be used is 525°C. The minimum holding time at tempering temperature is 2 hours.

Hardness, grain size and retained austenite as functions of austenitising temperature

SOFT ANNEALING

Protect the steel and heat through to 850°C. Then cool in furnace at 10°C per hour to 600°C, then freely in air.

QUENCHING MEDIA

High speed gas/circulating atmosphere Vacuum furnace (high speed gas with sufficient overpressure) Martempering bath, salt bath or fluidised bed at 500-550°C Martempering bath at 200–350°C

Note: Temper the tool as soon as its temperature reaches 50–70°C.

Tempering graph

Soaking time = time at hardening temperature after the tool is fully heated through.

Protect the tool against decarburisation and oxidation during austenitising.

DIMENSIONAL CHANGES

The dimensional changes have been measured after austenitising at 1020°C/30 minutes, followed by gas quenching in N2 at a cooling rate of 1.1°C/second between 800–500°C in a cold chamber vacuum furnace.

Specimen size: 100 x 100 x 100 mm.

Temperature °C

Soaking time minutes

Hardness before tempering

1000 30 61 HRC

1025 30 63 HRC

Heat treatment

STRESS RELIEVING

After rough machining, the tool should be heated through to 650°C, holding time 2 hours. Cool slowly to 500°C, then freely in air.

HARDENING

Preheating temperature: 600–650°C and 850–900°C. Austenitising temperature: 1000–1025°C, normally 1025°C.Holding time: 30 minutes

60

61

62

63

64

65

15

20

25

Grain sizeASTM Hardness, HRC Retained austenite, %

5

10

15

20

25

990 1000 1010 1020 1030 1040 1050°C

Austenitising temperature TA, 30 minutes

Grain size

Hardness

Retained austenite

50

52

54

56

58

60Hardness, HRC Retained austenite, %

48

46

10

15

20

25

30

35

5

500 520 540 560 580 600°C

Tempering temperature (2 x 2h)

TA=1025°C Retained austenite

TA=1025°C Hardness

TA=1000°C Hardness

0.16

Dimensional changes, %

0.12

0.08

0.04

0.00

-0.04500 520 540 560 580 600°C

Tempering temperature (2 x 2h)

1020°C Transverse

1020°C Short transverse

1020°C Longitudinal

10

5

6

UNIMAX

TURNING

Machining recommendations

MILLING

Face and square shoulder milling

Cutting data parameters

Milling with carbide

Rough milling Fine milling

Cutting speed (v

c)

m/min120 - 170 170 - 210

Feed (fz)

mm/tooth0.2 - 0.4 0.1 - 0.2

Depth of cut (ap)

mm2 - 4 0.5 - 2

Carbidedesignation ISO

P20 - P40Coated carbide

P10 Coated carbide

or cermet

Cutting data parameters

Turning with carbideTurning

with HSS†

Rough turning

Fine turning

Fine turning

Cutting speed (v

c)

m/min150 - 200 200 - 250 15 - 20

Feed (f) mm/r

0.2 - 0.4 0.05 - 0.2 0.05 - 0.3

Depth of cut (ap)

mm2 - 4 0.5 - 2 0.5 - 2

Carbide designation ISO

P20 - P30 Coated carbide

P10 Coated

carbide or cermet

-

Drill diameter mm

Cutting speed (vc)

m/minFeed (f) mm/r

≤ 5 15 - 20* 0.05 - 0.10

5 - 10 15 - 20* 0.10 - 0.20

10 - 15 15 - 20* 0.20 - 0.30

15 - 20 15 - 20* 0.30 - 0.35

* For coated HSS drill, vc~ 35–40 m/min

1 Drill with interntal cooling channels and brazed carbide tip2 Depending on drill diameter

Cutting data parameters

Type of drill

Indexable insert

Solid carbide

Brazed carbide1

Cutting speed (v

c)

m/min180 - 200 120 - 150 60 - 90

Feed (f) mm/r

0.03 - 0.102 0.10 - 0.252 0.15 - 0.252

End milling

1 For coated HSS end mill, vc~ 35–40 m/min

Cutting data parameters

Type of milling

Solid carbide

Carbide indexable

insert

High speed steel

Cutting speed (v

c)

m/min120 - 150 110 - 150 20 - 251

Feed (f) mm/tooth

0.01 - 0.202 0.06 - 0.202 0.01 - 0.302

Carbide designation ISO

- P20 - P30 -

Type of grindingSoft

annealed condition

Hardened condition

Face grinding straight wheel A 46 HV A 46 HV

Face grinding segments A 24 GV A 36 GV

Cylindrical grinding A 46 LV A 60 KV

Internal grinding A 46 JV A 60 IV

Profile grinding A 100 LV A 120 KV

The cutting data below are to be considered as guiding values and as starting points for developing your own best practice.

Condition: Soft annealed condition ~185 HB

Carbide drill

† High speed steel

DRILLING

High speed steel twist drill

GRINDING

Wheel recommendation

7

UNIMAX

WeldingWelding of die components can be performed, with acceptable results, as long as proper precautions are taken during the preparation of the joint, the filler material selection, the preheating of the die, the controlled cooling of the die and the post weld heat treatment processes. The following guidelines summarise the most important welding process parameters.

Following the EDM process, the applicable die surfaces are covered with a resolidified layer (white layer) and a rehardened and untempered layer, both of which are very brittle and hence detrimental to die performance.

If EDM is used, the white layer must be completely removed by grinding or stoning. After finish machining, the tool should be given an additional temper at approx. 25°C below the highest previous tempering temperature.

Further informationFor further information, i.e., steel selection, heat treatment, application and availability, please contact our ASSAB office nearest to you.

Surface treatmentTool steels may be given a surface treatment in order to reduce friction and increase wear resistance. The most commonly used treatments are nitriding and surface coating with wear-resistant layers produced via PVD or CVD.

The high hardness and toughness, together with a good dimensional stability, makes Unimax suitable as a substrate steel for various surface coatings.

NITRIDING AND NITROCARBURISING

Nitriding and nitrocarburising result in a hard surface layer, which is very resistant to wear and galling.

The surface hardness after nitriding is approximately 1000-1200 HV0.2kg. The thickness of the layer should be chosen to suit the application in question.

PVD

Physical vapour deposition, PVD, is a method for applying wear-resistant surface coating at temperatures between 200-500°C.

CVD

Chemical vapour deposition, CVD, is a method for applying wear-resistant surface coating at a temperature of around 1000°C.

Welding method TIG MMA

Preheating temperature1 200 - 250ºC 200 - 250ºC

Filler materialUTP ADUR600

UTP A73G2UTP 67S

UTP 73G2

Maximum interpass temperature2 350ºC 350ºC

Post weld cooling20 - 40ºC/h for the first two hours and then freely in air

Hardness after welding

54 - 60 HRC 55 - 58 HRC

Heat treatment after welding

Hardened condition

Temper at 510ºC for 2 h

Soft annealed condition

Soft anneal according to the “Heat treatment” recommendation.

Electrical discharge machining

1 Preheating temperature must be established throughout the die and must be maintained for the entire welding process, to prevent weld cracking2 The temperature of the tool in the weld area immediately before the second and subsequent pass of a multiple pass weld. When exceeded, there is a risk of distortion of the tool or soft zones around the weld.

8

UNIMAX

RESISTANCE TO FAILURE MECHANISMS AND CRITICAL MOULD STEEL PROPERTIES

Relative comparison of ASSAB plastic mould steels

ASSAB gradePlastic

deformationCracking Wear Corrosion Polishability

Thermal conductivity

Machinability

ASSAB 618

ROYALLOY

ASSAB 718 HH

NIMAX

CORRAX

POLMAX

MIRRAX ESR

STAVAX ESR

ASSAB 8407 SUPREME

UNIMAX

ELMAX

ASSAB XW-10

9

UNIMAX

10

UNIMAX

11

UNIMAX

MALAYSIA

Kuala Lumpur - Head OfficeASSAB Steels (Malaysia) Sdn. Bhd.Tel : +60 3 6189 0022Fax: +60 3 6189 0044/55info.kualalumpur@assab.com

NingboASSAB Tooling Technology(Ningbo) Co., Ltd.Tel : +86 574 8680 7188Fax: +86 574 8680 7166info.ningbo@assab.com

Cikarang*PT. ASSAB Steels IndonesiaTel : +62 21 461 1314Fax: +62 21 461 1306/ +62 21 461 1309info.cikarang@assab.com

Jiangxi*ASSAB Tooling (Dong Guan) Co, Ltd., Jiangxi BranchTel : +86 769 2289 7888Fax : +86 769 2289 9312info.jiangxi@assab.com

Tel : +62 21 5316 0720-1

Choosing the right steel is of vital importance. ASSAB engineers and metallurgists are always ready to assist you in your choice of the optimum steel grade and the best treatment for each application. ASSAB not only supplies steel products with superior quality, we offer state-of-the-art machining, heat treatment and surface treatment services to enhance steel properties to meet your requirement in the shortest lead time. Using holistic approach as a one-stop solution provider, we are more than just another tool steel supplier.

ASSAB and Uddeholm are present on every continent. This ensures you that high-quality tool steels and local support are available wherever you are. Together we secure our position as the world's leading supplier of tooling materials.

For more information, please visit www.assab.com