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UDDEHOLM STEEL FOR FORGING 1

UDDEHOLM TOOL STEELFOR FORGING APPLICATIONS

TOOLING APPLICATION HOT WORK

UDDEHOLM STEEL FOR FORGING2

This information is based on our present state of knowledge and is intended to provide generalnotes on our products and their uses. It should not therefore be construed as a warranty ofspecific properties of the products described or a warranty for fitness for a particular purpose.

Classified according to EU Directive 1999/45/ECFor further information see our “Material Safety Data Sheets”.

Edition: 1, 08.2010The latest revised edition of this brochure is the English version,which is always published on our web site www.uddeholm.com


CONTENTS

Hot forging of metals 4

Warm forging 7

Progressive forging 8

Effect of forging parameters on die life 10

Die design and die life 11

Requirements for die material 14

Manufacture and maintenance of forging die 16

Surface treatment 17

Tool steel product programme – general description 19 – chemical composition 20 – quality comparison 20

Tool steel selection chart 21

Cover photo: Part to an universal joint, Arvika Smide AB.

Most of the photos coming from Arvika Smide AB, Sweden andFiskars Brands Finland Oy Ab

Selecting a tool steel supplier is a key decision for all parties, including the tool maker, the tool

user and the end user. Thanks to superior material properties, Uddeholm’s customers get

reliable tools and components. Our products are always state-of-the-art. Consequently, we have

built a reputation as the most innovative tool steel producer in the world.

Uddeholm produce and deliver high quality Swedish tool steel to more than 100,000 customers

in over 100 countries. Some markets are served by ASSAB, our wholly-owned and exclusive

sales channel in Asia, Africa and South America. Together we secure our position as a world

leading supplier of tool steel.

Wherever you are in the manufacturing chain, trust Uddeholm to be your number one partner

and tool steel provider for optimal tooling and production economy.

Quite simply, it pays to go for a better steel.


Hot forging of metalsIn hot forging a heated up billet is pressedbetween a die set to a nearly finished product.Large numbers of solid metal parts are producedin aluminium alloys, copper alloys, steel or super-alloys where irregular shapes need to be com-bined with good mechanical properties. The mainmethods of drop forging are hammer forging andpress forging.

Hammer forgingHammer forging is characterized by a very shortcontact time and very rapid rate of increase offorce with time (impact loading). The cumulativecontact time for the bottom die can be fairly longif one includes the time between blows. However,since a lubricant with “blow-out” effect is nor-mally used with hammers, effective contact be-tween the part and the die only occurs during theactual forging blow.

These features imply that impact toughness andductility are important properties for die steel tobe used in hammer dies. This does not mean tosay that wear resistance is not important, particu-

larly in smaller dies, which in fact normally fail asa result of wear. In hammer forging, there is a lotto be said for using inserts of a more wear-resistant die steel which are shrink fitted into atough holder material.

For larger, high-production hammer dies, whichmay be resunk a number of times, it is importantthat the die steel used has sufficient hardenabilitythat the later cavities are not sunk in softermaterial with inferior wear resistance.

Press forgingIn press forging, the contact time under pressureis much longer, and the impact load is muchlower than in hammer forging. In general terms,this means that the heat resistance and elevatedtemperature wear resistance of the die steel arerelatively more important than the ability towithstand impact loading. However, one mustoptimize impact toughness and ductility in rela-tion to wear resistance; this applies particularlyfor large press dies which are not supportedfrom the sides. Since the surface temperature ofpress dies will during service generally be higherthan for hammer dies, it is important that the die


GROSS CRACKING

Forging dies might fail as a result of some formof gross cracking. This may occur during a singlecycle or, as is most common, over a number ofcycles; in the latter instance, the crack growthproceeds via a high-stress fatigue mechanism.Gross cracking is more frequent in hammerblocks than in press tooling, because of thegreater degree of impact.

surface is not excessively chilled by lubrication.Otherwise, premature heat checking or eventhermal shock cracking may result.

WEAR

If all other damage mechanisms are suppressed, aforging die will ultimately wear out (parts out oftolerance). Wear occurs when the work materialplus oxide scale glide at high velocity relative tothe cavity surface under the action of highpressure. It is most pronounced at convex radiiand in the flash land. Wear is increased drasticallyif the forging temperature is reduced (higher flowstress for the work material). The explosion

Typical die failuresThe deterioration of forging dies is usuallyassociated with several processes which mayoperate simultaneously. However, one of thesenormally dominates and is the ultimate cause offailure. In general, four distinct damage mecha-nisms can be distinguished:• wear

• mechanical fatigue and gross cracking

• plastic deformation

• thermal fatigue cracking (heat checking)

Different damage mechanisms can dominate indifferent parts of the cavity.

Thermal fatigue Wear Wear

which occurs via combustion of oil-basedlubricant in the confined space between forgingand die can also give rise to a type of erosivewear.

Wear.

Thermal Cracking Wear Plastic fatigue deformation


Gross cracking is a failure condition which canalmost always be rectified. Normally, cracking liesin one or more of the following:

• overloading, e.g. work material temperaturetoo low

• die design, e.g. too sharp radii or too thin wallthickness

• inadequate preheating of the die

• inadequate toughness of die steel (wrongselection)

• too high hardness of die material

• poor quality heat treatment/surface treatment

• inadequate die support/alignment

PLASTIC DEFORMATION

This occurs when the die is locally subjected tostresses in excess of the yield strength of the diesteel. Plastic deformation is quite common atsmall convex radii, or when long thin toolingcomponents e.g. punches, are subjected to highbending stresses.

The following can be the cause of plasticdeformation in forging dies:

• too low billet temperature (high flow stress ofwork material)

• inadequate hot strength of die steel

• die temperature too high

• die material too soft

THERMAL FATIGUE CRACKING

This results if the surface of the cavities issubjected to excessive temperature changesduring the forging cycle. Such temperaturechanges create thermal stresses and strains atthe die surface which eventually lead to crackingvia a low-cycle fatigue mechanism (heat checking).

Totally cracked die.

Heat checked die surface.

Thermal fatigue cracking is increased by thefollowing factors:• cavity surface at too high temperature

(excessive billet temperature and/or longcontact time)

• excessive cooling of die surface betweenforgings

• inadequate preheating of die• wrong selection of die steel and/or poor heat

treatment

All these factors will increase the differencebetween maximum and minimum temperature inthe die surface.


Warm forgingWarm forging is a precision forging operationcarried out at a temperature range between550–950°C (1020–1740°F). It is useful for forgingof details with intricate shapes, with desirablegrain flow, good surface finish and tighter dimen-sional tolerances than if hot forged.

The weight of the forged piece is between0.1–50 kg (0.22–110 lbs) and the production rateabout 10–40 pieces per minute. The contact timeis about 200 ms and the mechanical loads at600°C (1110°F) are 3 to 5 times higher than inhot forging. Automatic multi-station presses withintegrated cooling/lubricating systems are oftenused.

UPSETTING

Tube Rod

FORWARD EXTRUSION

Punch

Die

IRONING

LATERAL EXTRUSION

HEADING

OPEN DIE EXTRUSION

Reducing

BACKWARD EXTRUSION

Can

Typical processes in warm forging.

Die material propertiesThe properties profile required for tool steel inforging dies depends to some extent on the typeof forging operation, on the work material andon the size of the part, depth of cavity etc.However, a number of general characteristics willalways be required in all forging operations. Theparticular die damage mechanisms are given inparentheses.

• Sufficient hardness and ability to retain this atelevated temperatures—temper resistance(wear, plastic deformation, thermal fatiguecracking).

• Enhanced level of hot tensile strength and hothardness (wear, plastic deformation, thermalfatigue cracking).

• Good toughness and ductility at low andelevated temperatures (gross cracking, thermalshock cracking, thermal fatigue cracking). It isimportant that the die steel exhibits adequatetoughness/ductility in all directions.

• Adequate level of fatigue resistance (grosscracking).

• Sufficient hardenability (retention of wearresistance etc. if the die is resunk).

• Amenability to weld repair.

• Good machinability, especially prehardeneddie blocks.

Workmaterial


Progressive forgingIn progressive forging a large number of sym-metrical, precision-forged parts with forgedweights of up to about 5 kg (11 lbs) are pro-duced. The fully automatic process involvessupplying hot rolled bars at one end of the line,heating them inductively, cutting them to the

required size, shaping them in 3–4 stages anddischarging finished forgings at the other end ofthe line.

Depending on the weight of the forgings,production capacity is between 50 and 180 perminute.

Typical failuresTool parts used in the progressive forging, such asdie, stem, stem holder, punch and counter punch-ejector are subjected to very high stresses.

As the production speed is very high, the dieparts need to be water-cooled to protect themagainst overheating. Nevertheless, despite inten-sive cooling, the tool surfaces can be stronglyheated, even by the brief contact, with the hotmetal being forged.As a result of this alternate heating and coolingthe die parts are subjected to extremely highthermal fatigue. The degree of the thermal fatiguecracking constitutes a measure of the materiallife.

An additional factor is the degree of hot wearof the material, which depends on the surfacetemperatures and the mechanical stresses on thedie.

Tool material propertiesThe required properties profile of the hotforming die and die parts are:

• high temperature strength and good temperresistance to withstand hot wear and thermalfatigue cracking

• good thermal conductivity to withstand thermalfatigue cracking

• good hot ductility and toughness to resistinitiation and rapid spread of thermal fatiguecracking

Typical failuresDuring the warm forging operation the tool partsare exposed to rather high temperature, highmechanical loads and intensive cooling.

As a result of this alternate heating and coolingthe tool parts are subjected to high thermalfatigue.

An additional factor is the degree of hot wearof the material, which depends on the surfacetemperatures and the mechanical stresses on thetool.

Tool material propertiesThe tool parts are subjected to both highmechanical stresses and high thermal stresses.For these reasons a tool steel has to be chosenwhich has a good temper resistance, good wearresistance, high hot yield strength, good thermalconductivity and good thermal fatigue resistance.A warm forging steel must exhibit a propertiesprofile which is in between the typical propertiesprofiles for hot work and cold work steel.


1

1

2

5

7

3

4

68

59 6

6a

6

6a

8

7a

5

8 911

10

1 2 3 4 5 6 6a 7 7a 8 91011

Two-part cutting bushWork metalStopperCutterBlankStem/PunchHollow punchBolsterCounter punch-ejectorDieWaste metalPiercerProduct

FORGING IN A FULLY AUTOMATIC PROCESSS


Effect of forgingparameters on die lifeApart from the influence of the actual die mate-rial and its heat treatment/surface treatment, anumber of parameters related to the forgingoperation affect die life:

• billet temperature

• billet shape and surface condition

• work material

• cavity stress level and contact time

• type of forging operation

• type of lubricant

Billet temperatureReduced billet temperature in forging is favour-able from the viewpoint of mechanical propertiesin the forged part itself. This is particularly impor-tant if the components are not heat treated afterforging. However, the higher flow stress of thework material, which is associated with a re-duced forging temperature, results in both in-creased wear and a higher risk for plastic defor-mation. Further, since the forging loads increase,the probability for gross cracking is enhanced.

TYPICAL HOT FORGING TEMPERATURES

STEEL 1050–1250°C (1920–2100°F)

CU-ALLOYS 650–800°C (1200–1470°F)

AL-ALLOYS 350–500°C (660–930°F)

TI-ALLOYS 800–1000°C (1470–2010°F)

Billet shape and surface conditionThe greater the difference between the shape ofthe billet and that of the final forging, the greateris the degree of wear because the relativemovement between work material and die mustincrease. Likewise, hard, adherent scale on thebillet surface will increase wear, especially if thegliding distance is large.

Work materialThe higher the flow stress of the work material,the faster is die deterioration due to wear and/orplastic deformation, at the same time as the riskfor gross cracking is increased. Hence, stainlesssteel is more difficult to forge than carbon steelat the same temperature.

Forgeability of different types of material.

Low Moderate High

High

Moderate

Low

Constructural

Al–Mg-alloys

Stainless

Ti-alloys

Ni- andCo- alloys

FORGEABLILITY

IMPACT ENERGY OR PRESS POWER


Die design and die lifeAssuming that the forging equipment is in goodcondition (properly adjusted and without exces-sive play in the ram guide system), then adher-ence to the following “die design” principles willreduce the risk for catastrophic die failure:

• proper die support

• dovetails, if used, should be properly dimen-sioned, have sufficiently large radii and beproperly finished (grinding marks should betangential and not axial), see figure below.

• sufficient wall thickness, and sufficient materialbelow the cavity and between individualcavities

• adequate radii and fillets in the cavity

• proper dimensioning of flash land and gutter

• proper design of parting plane and, if used, dielocks

• correct use and design of setting plugs,punches and knockout pins

• sufficiently large cushion-face area in hammerforging in relation both to die block thicknessand to the capacity of the hammer used

Improper die support, insufficient material thick-ness in the die and too small radii are all verycommon reasons for a die failing catastrophicallyby cracking, and will be further enlarged upon.

Cavity stress leveland contact timeAn increased stress level in the cavity, can befound, for example, in high precision forging, andhas the following consequences:

• increased stress in the tool with higher risk fordeformation or gross cracking

• increased heat transfer from billet to die(heat checking)

• more pronounced wear

Prolonged contact, between billet and die duringforging, results in accelerated wear and a greaterrisk for heat checking. For very long contacttimes, the surface layer of the tool may becomeso hot that it transforms to austenite. Crackingproblems can then be experienced if this layerrehardens during the cooling part of the cycle.

Type of forging operationBecause of the much higher impact load, hammerdies tend to fail by cracking to an extent which isgreater than in press forging where the loadingrate is lower. Thermal fatigue (heat checking) ismore common in powder forging and othernear-net-shape forging processes involving longcontact times.

Type of lubricantOil-based lubricants can give rise to excessivewear/erosion due to the explosion-like combus-tion of the oil between billet and cavity. On theother hand, water base lubricants cool the diesurface to a greater extent which increases therisk of thermal fatigue cracking.

Grinding of dovetail radii.


Die supportIt is very important that the die is properlysupported underneath by a perfectly flat backingsurface with sufficient hardness. Concave depres-sions in the support surface immediately underthe die cavity are particularly deleterious becausethey exaggerate the tensile stresses at radii.

Proper backing is especially important inhammer forging because there is usually no sidesupport in this case. When dies of greatlydifferent dimensions are used on the same pressor hammer, it is essential to remove any cavitiesin the backing block or plate when switchingfrom a small to a large die.

For press forging, side support of the die isdesirable but this is not always possible. Shrinkfitting of inserts into a massive holder providesthe best security against cracking in press dies.

Fillet radiiThe greatest tensile stresses in a forging dieoccur at the radii between the sides and bottomof the cavity. The smaller the radius, the higherthe stresses. In general, the forging should bedesigned so that die fillet radii less than 2 mm(0.08 inch) can be avoided. For deeper cavities,>50 mm (>2 inch), this radius limit needs to beincreased to 5 mm (0.2 inch).

It is especially important during die making thatradii are ground and polished with grindingmarks, if any, in the tangential direction. In par-ticular, EDM residues, which may contain cracks,must be removed completely at radii (and prefer-ably from the rest of the die as well). If this is notpossible, then the die should at least be retem-pered at 25°C (50°F) below the previous tem-pering temperature.

Die material and wall thicknessA number of more or less empirical methods ordimensioning of forging dies are available, whichrange in complexity from simple “rule of thumb”to fairly advanced nomograms with a theoreticalbase. However, there is no doubt that thestresses imparted to the die by a given forgingmachine increase profoundly as the die dimen-sions are decreased.

Minimum height (Hmin) of hammer dies with amaximum depth of cavity (hmax).

hmax

Hmin

Hmin,inch mm

16 400

14 350

12 300

10 250

8 200

6 150

4 10010 25 50 75 100 125 150 mm 0.4 1 2 3 4 5 6 inch

hmax

As a rule of thumb for solid die blocks in pressforging the thickness below the cavity should beat least 1.5 x cavity depth.

As a minimum wall thickness in hammerforging the recommendations are according tothe table below.

t

h

Depth of cavity (h) mm inch

Distancecavity to outeredge of a die (t) mm inch

6 0.2 12 0.510 0.4 20 0.816 0.6 32 1.325 1.0 40 1.640 1.6 56 2.263 2.5 80 3.2

100 3.9 110 4.3125 4.9 130 5.1160 6.3 160 6.3

Minimum wall thickness (t) recommended in hammerdies between cavity and outer edge.


Requirementsfor die material

HardenabilityIn large press or hammer dies made from pre-hardened die steel, it is important that the hard-ness is uniform throughout the block. If the diesteel has too low hardenability, the block willbecome softer away from its outer surface anddie life for deep cavities or after progressiveresinking will be impaired.

Toughness and ductilityThe surface of the cavity can during use easilydevelop small cracks or other blemishes whichmay propagate in an unstable manner under theaction of the high forging stresses, especially atradii etc. Notch toughness indicates the ability ofthe die material to resist crack developmentfrom such defects.

All products, in the Uddeholm tool steel pro-gramme for the forging industry, are character-ized by the highest levels of toughness and duc-tility in all directions in the bar or block. Hence,the forger can rest assured that the resistance togross cracking is the highest possible in diesmade from Uddeholm die steel.

Proper die preheating will considerably reducethe risk for catastrophic failure via cracking.

Temper resistanceThe better the steel retains its hardness as thetemperature or the time increases, the better itstemper resistance.

Temper resistance can be assessed from thetempering curve for a hardened tool steel. In this,the hardness at room temperature is plottedagainst tempering temperature for given temper-ing time. Another method of presenting temperresistance data is to plot room temperaturehardness against time at a given tempering tem-perature.

Hot strength and hot hardnessIn contrast to temper resistance, which is definedin terms of hardness at room temperature, hotstrength and hot hardness refer to properties athigh temperature. In general, improved temperresistance is associated with increased hotstrength and hot hardness. It can be pointedout that good hot hardness and hot strength areimportant prerequisites for enhanced wearresistance at elevated temperatures.

A high level of hot hardness and hot strength isalso important in order to achieve adequate re-sistance to thermal fatigue cracking.

Fatigue resistanceUddeholm tool steel for forging dies are pro-duced to the highest possible quality standards,especially with regard to freedom from non-metallic inclusions. This imparts a degree offatigue resistance which is adequate for even themost demanding applications where forging diesare subjected to cyclic loading with high maxi-mum loads.


QRO 90 SUPREME

DIEVAR

ORVAR SUPREME

VIDAR SUPERIOR

ORVAR SUPERIOR

HOT STRENGTH

100 200 300 400 500 600°C

200 400 600 800 1000 1200°F

TESTING TEMPERATURE

DIEVAR

ORVAR SUPREMEand ORVAR SUPERIORVIDAR SUPERIOR

NOTCH TOUGHNESS

100 200 300 400 500°C

200 400 600 800 1000°F

TESTING TEMPERATURE

QRO 90 SUPREME


Manufacture andmaintenance of forging dieMachinability, weldability and, when applicable,response to heat treatment and surface treat-ment are important parameters influencing therelative ease of manufacture and maintenance offorging dies.

MachinabilityMachinability is a vital consideration when forgingdies are machined from prehardened die blocks.

The tool steel for forging applications fromUddeholm are characterized by freedom fromoxidic inclusions and a uniform microstructure.These features, in combination with the lowhardness in the annealed condition usually 170–200 HB, are to ensure excellent machinability.

“Grinding of tool steel” and “Electrical DischargeMachining (EDM) of tool steel”.

Heat treatmentIf forging dies are manufactured from die steel inthe annealed condition, then the tool must subse-quently be heat treated in order that the steeldevelops its optimum combination of hardness,toughness, heat resistance and wear resistance.

These properties are controlled throughproper choice of austenitizing temperature, cool-ing conditions during hardening and temperingtemperature and time. The Uddeholm brochure“Heat treatment of tool steel” will be worthconsulting.

For forging dies, where toughness is of theutmost importance, it is essential that the coolingrate during hardening is sufficiently rapid thatundesirable microconstituents such as

Even if these grades are supplied prehardened,the extreme cleanliness and microstructuralhomogeneity ensure that machining can normallybe carried out without difficulty.

For all products, advanced process controlguarantees that the variations in machiningcharacteristics are minimal from batch to batch.

Uddeholm’s product brochures give detailedinformation regarding machining of the products.Other Uddeholm publications worth consultingin the context of forging die manufacture are

pronounced grain-boundary carbide precipitation,pearlite and coarse upper bainite can be avoided.Furthermore, the austenitizing conditions shouldbe such that excessive grain growth can notoccur, since this is detrimental as regards totoughness. Because forging dies are sometimesEDM’d extensively after heat treatment, there isgenerally no problem to cope with the greaterdimensional change and distortion which resultswhen the rate of cooling during hardening israpid. Remember, however, that EDM’d dies

10 15 25 35 65 600°C/min.50 60 75 95 150 1110°F/min.

NOTCH TOUGHNESS

Notch toughness of Uddeholm Orvar Supreme, 44–46 HRC, as a function of quench rate.


Bending strength of Uddeholm Orvar Supreme as a function of nitriding depth.

should always be given an additional temper atabout 25°C (50°F) below the previous temperingtemperature. Detailed heat treatment recom-mendations for the various grades, in Uddeholm’stool steel programme for forging dies, are givenin the product brochure for each individualproduct.

Weld repair of forging diesCracked or worn forging dies are often refur-bished via welding. This is especially true in thecase of large dies where the tool steel itself rep-resents a considerable portion of the total diecost.

Further information can be obtained from theUddeholm publication “Welding of tool steel”.

Surface treatmentThe cavity in forging dies is quite often surfacetreated in order to enhance wear resistance.

NitridingNitriding is a thermochemical treatment giving ahard surface layer which is very resistant to wear.In favourable cases, the process also renders acompressive residual stress in the surface of thedie which helps counteract heat checking.

However, the nitrided layer is very brittle andmay crack or spall when subjected to mechanicalloading, especially impact loading. Nitriding isusually carried out by one of four methods, nitro-carburizing in salt-bath or gas, gas nitriding orplasma (ion) nitriding.

Before nitriding, the tool should be hardenedand double tempered, the latter at a temperatureat least 25–50°C (50–90°F) above the nitridingtemperature.

The surface hardness attained, and the thick-ness of the nitrided layer, depend on the nitridingmethod, nitriding time and the character of thesteel being treated. Typical data can be found inthe Uddeholm product brochures for the differ-ent tool steel.

Nitriding to layer thicknesses >0.3 mm(>0.012 inch) is not to be recommended forforging dies. The reason is that the nitrided layeris brittle and easily cracks during service. Theunderlying steel can not resist the propagation ofsuch surface cracks if the layer thickness is toogreat and the entire die may fail catastrophically.0.3 mm (0.012 inch) maximum nitride layer thick-ness is a general recommendation; this maximumvalue should be decreased if the impression hasvery sharp radii or if the die steel is used at highhardness.

The formation of the so-called “white layer”should also be avoided because of brittleness.

BENDING STRENGTH

0.05 0.15 0.30 0.45 mm 0.0016 0.006 0.012 0.018 inch NITRIDING DEPTH

200°C (390°F)

20°C (70°F)


UDDEHOLMTOOL STEEL

DIEVAR

UNIMAX

ORVAR 2 MICRODIZED

ORVAR SUPREME/ORVAR SUPERIOR

VIDAR SUPERIOR

QRO 90 SUPREME

HOTVAR

ALVAR 14

VANADIS 23VANADIS 30

A premium Cr-Mo-V-alloyed hot work die steel with good high temperaturestrength and excellent hardenability, toughness and ductility. It meets therequirements of NADCA #207-2008.

A premium Cr-Mo-V alloyed steel with a good toughness and ductility up toa hardness of 58 HRC.

Cr-Mo-V-alloyed hot work die steel (H13) with good high temperaturestrength and hot wear resistance.

Premium Cr-Mo-V-alloyed hot work die steel (H13) with good resistance tothermal fatigue. The steel are produced by a special melting and refiningtechnique. They meet the requirements of NADCA #207–2008.

A premium Cr-Mo-V alloyed hot work die steel (H11 modified) with goodresistance to cracking. It meets the requirements of NADCA #207–2008.

A premium hot work die steel with high hot yield strength and good temperresistance. It also has good thermal conductivity.

A premium hot work die steel with very good high temperature properties.Can be hardened and tempered to 58 HRC, giving an outstanding hot wearresistance. Recommended for applications where hot wear and/or plasticdeformation are the dominating failure mechanisms.

Cr-Ni-Mo-alloyed hot work steel. Normally delivered in prehardenedcondition for solid die blocks.

PM-produced high speed steel. Recommended for forging applications wherevery good wear resistance is needed.

Tool steel product programme for forging applicationsGENERAL DESCRIPTION


SUPPLIED AISI ANALYSIS % HARDNESS

(W.-Nr.) C Si Mn Cr Mo V Others Brinell

DIEVAR – 0.35 0.2 0.5 5.0 2.3 0.6 – ~160

UNIMAX – 0.50 0.2 0.5 5.0 2.3 0.5 – ~185

ORVAR 2 MICRODIZED H13 0.39 1.0 0.4 5.3 1.3 0.9 – ~180

(1.2344)

ORVAR SUPREME H13 0.39 1.0 0.4 5.2 1.4 0.9 – ~180(1.2344)

ORVAR SUPERIOR H13 0.39 1.0 0.4 5.2 1.4 0.9 – ~180

(1.2344)

VIDAR SUPERIOR H11 modified 0.36 0.3 0.3 5.0 1.3 0.5 – ~180(1.2340)

QRO 90 SUPREME – 0.38 0.3 0.8 2.6 2.3 0.9 Micro-alloyed ~180

HOTVAR – 0.55 1.0 0.8 2.6 2.3 0.9 – ~210

ALVAR 14 (1.2714) 0.55 0.3 0.7 1.1 0.5 0.1 Ni 1.7 ≤250 orprehardened

CHEMICAL COMPOSITION

UDDEHOLMTOOL STEEL

QUALITATIVE COMPARISON OF RESISTANCE OF BASIC PROPERTIES

The longer the bar, the better.

UDDEHOLMTOOL STEEL

DIEVAR

UNIMAX

ORVAR 2 M

ORVAR SUPREME

ORVAR SUPERIOR

VIDAR SUPERIOR

QRO 90 SUPREME

HOTVAR

ALVAR 14

PLASTIC PREMATURE HEATHOT WEAR DEFORMATION CRACKING CHECKING


Tool steel selection chartGENERAL RECOMMENDATIONS

FORGING UDDEHOLM HARDNESS CAVITY APPLICATION STEEL GRADE RANGE DEPTH

HAMMERFORGING Solid die blocks ALVAR 14 – Prehardened 400–440 HB max 20 mm

(0.8 inch)360–400 HB max 50 mm

(2 inch)320–360 HB max 150 mm

(6 inch)≤320 very deep

Inserts VIDAR SUPERIORDIEVARORVAR SUPREMEORVAR SUPERIOR 38–50 HRC

PRESS FORGING Dies DIEVARVIDAR SUPERIORORVAR SUPREMEORVAR SUPERIORQRO 90 SUPREMEHOTVARUNIMAX 38–57 HRC

WARM FORGING Tools HOTVARUNIMAXDIEVAR 50–58 HRC*

PROGRESSIVEFORGING Tools QRO 90 SUPREME

HOTVARUNIMAXDIEVAR 48–54 HRC*

HOT STAMPING Dies/Inserts QRO 90 SUPREMEHOTVARDIEVARUNIMAX 46–56 HRC

UPSET FORGING Tools UNIMAXHOTVARDIEVAR 46–56 HRC

* Uddeholm PM grades can be used in some tool parts. Higher hardnesses can be used.

www.assab.com www.uddeholm.com www.uddeholm.com

Network of excellenceUDDEHOLM is present on every continent. This ensures you

high-quality Swedish tool steel and local support wherever you

are. ASSAB is our wholly-owned subsidiary and exclusive sales

channel, representing Uddeholm in various parts of the world.

Together we secure our position as the world’s leading supplier

of tooling materials.


UD

DEH

OLM

100801.1000 / TRYC

KERI KNA

PPEN, KA

RLSTAD

201004296

UDDEHOLM is the world’s leading supplier of tooling materials. This

is a position we have reached by improving our customers’ everyday

business. Long tradition combined with research and product develop-

ment equips Uddeholm to solve any tooling problem that may arise.

It is a challenging process, but the goal is clear – to be your number one

partner and tool steel provider.

Our presence on every continent guarantees you the same high quality

wherever you are. ASSAB is our wholly-owned subsidiary and exclusive

sales channel, representing Uddeholm in various parts of the world.

Together we secure our position as the world’s leading supplier of

tooling materials. We act worldwide, so there is always an Uddeholm

or ASSAB representative close at hand to give local advice and support.

For us it is all a matter of trust – in long-term partnerships as well as in

developing new products. Trust is something you earn, every day.

For more information, please visit www.uddeholm.com, www.assab.com

or your local website.

ASSAB

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