DIEVAR - Home | ASSAB

1 UDDEHOLMDIEVARDIEVAR223 DievASSAB is a trademark of ASSAB Pacific Pte 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 D1141010 REFERENCE STANDARD DF-2 ARNEO1( )(SKS 3) ASSAB DF-3O1( )(SKS 3) ASSAB XW-5 SVERKER 3D6 (D3)( )(SKD 2) ASSAB 12 ASSAB XW-41 SVERKER 11 ASSAB 88 SLEIPNERASSAB PM 23 SUPERCLEANVANADIS 23 SUPERCLEAN(M3:2) 53 ASSAB PM 30 SUPERCLEANVANADIS 30 SUPERCLEAN(M3.)

2 2 + Co) 40 ASSAB PM 60 SUPERCLEANVANADIS 60 SUPERCLEAN( )VANADIS 4 EXTRA SUPERCLEANVANADIS 4 EXTRA SUPERCLEANVANADIS 6 SUPERCLEANVANADIS 6 SUPERCLEANVANADIS 10 SUPERCLEANVANADIS 10 SUPERCLEANVANCRON 40 SUPERCLEANVANCRON 40 SUPERCLEANELMAX SUPERCLEANELMAX SUPERCLEANASSAB 618P20 618 HHP20 618 TP20 718 SUPREMEIMPAX SUPREMEP20 718 HHIMPAX HHP20 40 MIRRAX 40420 1 ESRVIDAR 1 6 UNIMAXUNIMAXCORRAXCORRAXASSAB 420J2 STAVAX ESRSTAVAX ESR420 ESRSUS 420J2 MIRRAX ESRMIRRAX ESR420 HHRAMAX HH420 F PT18 ASSAB MMXLASSAB MM40 ALVAR 14 ALVAR 4 ASSAB 4 ASSAB 8407 2 MORVAR 61 ASSAB 8407 SUPREMEORVAR SUPREMEH13 ESRSKD 61 DIEVARDIEVARHOTVARHOTVARQRO 90 SUPREMEQRO 90 SUPREMEFORMVARFORMVARASSAB is a hot work die steel specially developed

3 By Uddeholm Tooling, our steel mill in Sweden, to provide the best possible chemical composition and the very latest in production technique make the property profile outstanding. DIEVAR possesses a combination of excellent toughness and very good hot strength, resulting in a superior hot work die steel that have excellent resistance to heat checking and gross is suitable for high demand hot work applications like die casting, extrusion and forging. The property profile also makes it a suitable choice in other applications such as plastic moulding ( , to solve chipping/cracking) and High Performance offers the potential for significant improvements in die life, thereby improving the tooling alloyed hot work tool steelStandard specificationNoneDelivery conditionSoft annealed to approx.

4 160 HBColour codeYellow / GreyDIE CASTINGEXTRUSIONPartAluminium / Magnesium alloysDies44-50 HRCPartCopperalloysAluminium / Magnesium alloysDies-46-52 HRCL iners, dummy blocks, stems46-52 HRC44-52 HRCG eneral DIEVAR is a high performance chromium-molybdenum-vanadium alloyed hot work tool steel which offers a very good resistance to heat checking, gross cracking, hot wear and plastic deformation. DIEVAR is characterised by: Excellent toughness and ductility in all directions Good temper resistance Good high-temperature strength Excellent hardenability Good dimensional stability throughout heat treatment and coating operationsDievar is a premium hot work tool steel developed by Uddeholm. It is manufactured utilising the very latest in production and refining techniques.

5 The DIEVAR development has yielded a die steel with the ultimate resistance to heat checking, gross cracking, hot wear and plastic deformation. The unique properties profile of DIEVAR makes it the best choice for die casting, forging and checking is one of the most common failure mechanisms, , in die casting and nowadays also in forging applications. DIEVAR s superior ductility yields the highest possible level of heat checking resistance. With DIEVAR s outstanding toughness and hardenability, its resistance to heat checking will be further improved. If gross cracking is not a factor, then a higher workinghardness can be utilised (+2 HRC).Regardless of the dominant failure mechanism ( , heat checking, gross cracking, hot wear or plastic deformation)

6 , DIEVAR offers the potential for significant improvements in die life as well as tooling is the material of choice for the high demand die casting, forging and extrusion FORGINGPartSteel / AluminiumInserts44-52 HRC523 DievPropertiesTemperature20 C400 C600 CDensity kg/m3780077007600 Modulus of elasticity MPa210 000180 000145 000 Coefficient of thermal expansion per C from 20 x x 10-6 Thermal conductivity W/m C-3132 MECHANICAL PROPERTIESA pproximate tensile properties at room temperature, tested in the short transverse HRC48 HRC52 HRCT ensile strength, Rm1480 MPa1640 MPa1900 MPaYield strength, MPa1380 MPa1560 MPaElongation, A513 %13 % %Reduction ofarea, Z55 %55 %52 %The reported properties are representative of samples which have been taken from the centre of a 610 x 203 mm bar.

7 Unless otherwise indicated, all specimens were hardened at 1025 C, quenched in oil and tempered 2 + 2 hours at 615 C to 45 1 PROPERTIESH ardened and tempered to 44 - 46 tensile properties at elevated temperaturesShort transverse direction, 45 1 V-notch impact toughness at elevated temperaturesShort transverse a hardness of approximately 45 HRC, the minimum average unnotched impact ductility is 300 J in the short transverse resistanceThe specimens have been hardened and tempered to 45 HRC, and then held at different temperatures from 1 to 100 hours. 100200300400500700 C600 Testing temperature20040060080010001200140016001 8002000Rm, , Z% temperature100150200250300350400450 C20406080100120140 Impact energy, J50 HRC47 HRC45 , h253035404550 Hardness, HRC500 C550 C600 C650 C623 DievHardness, grain size and retained austenite as functions of austenitising temperatureSOFT ANNEALINGP rotect the steel and heat through to 850 C.

8 Then cool in the furnace at 10 C per hour to 650 C, then freely in graphSoaking time = time at hardening temperature after the tool is fully heated the tool against decarburisation and oxidation during CSoaking time minutesHardness before tempering10003052 2 HRC10253055 2 HRCHeat treatmentSTRESS RELIEVINGA fter rough machining, the tool should be heated through to 650 C, holding time 2 hours. Cool slowly to 500 C, then freely in temperature: 600 900 C. Normally a minimum of two preheats, the first in the 600 650 C range, and the second in the 820 850 C range. When three preheats are used, the second is carried outat 820 C, and the third at 900 temperature: 1000 1030 CTEMPERINGC hoose the tempering temperature according to the hardness required by reference to the tempering graph below.

9 Temper at least three times for die casting dies, and two times for forging and extrusion tools. The tool should be cooled to room temperature between the tempers. The minimum holding time at tempering temperature is 2 in the range of 500 550 C is normally not recommended, and it will result in a lower a general rule, quench rates should be as rapid as possible. Accelerated quench rates are required to optimise tool properties specifically with regards to toughness and resistance to gross cracking. However, risk of excessive distortion and cracking must be quenching media should be capable of creating a fully hardened microstructure. Different quench rates for DIEVAR are defined by the CCT graph as shown in page 7.

10 High speed gas/circulating atmosphere Vacuum (high speed gas with sufficient positive pressure). An interrupted quench at 320 450 C is recommended for distortion control, or when quench cracking is a concern. Martempering bath, salt bath or fluidised bed at 450 550 C Martempering bath, salt bath or fluidised bed at approx. 180 200 C Warm oil, approx. 80 CNote: Temper the tool as soon as its temperature reaches 50 70 temperture 990100010101020103010401050 C5052545658601086024 GrainsizeASTM Hardness, HRCR etained austenite %Grain sizeHardnessRetained austenite Tempering temperature (2 + 2h)100200300400500600700 C2530354045505560 Hardness, HRCR etained austenite, %Retained austeniteTemper1000 CAustenitising temperature1025 C246723 DievCCT graphAustenitising temperature 1025 C.