Conducted by the Die Materials Specification Subcommittee October 16th & 17th, 2007 Die Materials Specification Task Group Die Steel Quality & Heat Treatment

Conducted by the

Die Materials SpecificationSubcommittee

October 16th & 17th, 2007

Die Materials Specification Task GroupDie Materials Specification Task Group

Die Steel Quality & Heat Treatment Acceptance Criteria


#207-2006


NADCA Material CategoryGrade C Mn P S Si Cr Mo V

"Grade A" Type H13 - Premium0.37 - 0.42

0.20 - 0.50

0.025 max

0.005 max

0.80 - 1.20

5.00 - 5.50

1.20 - 1.75

0.80 - 1.20

"Grade B" Type H13 - Superior0.37 - 0.42

0.20 - 0.50

0.015 max

0.003 max

0.80 - 1.20

5.00 - 5.50

1.20 - 1.75

0.80 - 1.00

"Grade C" Type 2367 & Modified0.32 - 0.40

0.10 - 0.60

0.020 max

0.003 max

0.10 - 0.50

4.70 - 5.30

2.00 - 3.30

0.40 - 0.70

"Grade D" Type H11 / 23430.35 - 0.42

0.20 - 0.60

0.025 max

0.003 max

0.80 - 1.20

5.00 - 5.50

1.10 - 1.60

0.30 - 0.60

"Grade E" Type H11 Modified0.32 - 0.43

0.10 - 0.70

0.020 max

0.003 max

0.10 - 0.55

4.70 - 5.70

1.10 - 2.10

0.30 - 0.80

TABLE 1 - Chemical Composition of Special Quality Die Steels



D. Preheating Practice • Load work into cold furnace and heat at a rate not to exceed 400°F/hour (220°C/hour) as measured by Tc.

• Heat to 1000°F to 1250°F (540°C to 675°C) furnace temperature and hold until Ts-Tc<200°F (110°C).

• Heat to 1550°F ± 50°F (845°C ± 28°C) and hold until Ts - Tc < 100°F (55°C).

• Additional preheating steps may be used at the discretion of the heat treater or toolmaker.

D. Preheating Practice • Load work into cold furnace and heat at a rate not to exceed 400°F/hour (220°C/hour) as measured by Tc.

• Heat to the 1st designated Preheat temperature in Table 2 and hold until Ts – Tc <200°F (110°C).

• Heat to the 2nd designated Preheat temperature in Table 2 and hold until Ts - Tc < 25°F (14°C).

• Additional preheating steps may be used at the discretion of the heat treater or toolmaker.


TABLE 2 - Heat Treatment Parameters and Impact Toughness

NADCAPreheating

TemperatureGrade & Type °F (°C) °F °C Avg Min Avg Min

A1885 1885 1030 8 (10.8) 6 (8.1) na na

B1885 1885 1030 10 (13.6) 8 (10.8) 8 (10.8) 6 (8.1)

C1885 1885 1030 10 (13.6) 8 (10.8) 8 (10.8) 6 (8.1)C1850 1850 1010 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)

D1830 1830 1000 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)

E1885 1885 1030 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1850 1850 1010 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1825 1825 995 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1810 1810 990 22 (29.8) 18 (24.4) 18 (24.4) 15 (20.3)

*

** Toughness of test coupon removed from detail after commercial vacuum hardening; minimum double tempered (triple tempered preferred) to 44/46 HRC.

Capability toughness after oil quench and minimum double temper (triple tempered preferred) to 44/46 HRC

Hardening Temperature

"Annealed" Steel Capability CVN*,

ft-lbs (J)

"Class 1" Hardened Steel CVN**, ft-lbs (J)


TABLE 2 - Heat Treatment Parameters and Impact Toughness

NADCAPreheating

TemperatureGrade & Type °F (°C) °F °C Avg Min Avg Min

A1885 1885 1030 8 (10.8) 6 (8.1) na na

B1885 1885 1030 10 (13.6) 8 (10.8) 8 (10.8) 6 (8.1)

C1885 1885 1030 10 (13.6) 8 (10.8) 8 (10.8) 6 (8.1)C1850 1850 1010 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)

D1830 1830 1000 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)

E1885 1885 1030 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1850 1850 1010 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1825 1825 995 14 (19) 11 (14.9) 11 (14.9) 9 (12.2)E1810 1810 990 20 (27) 17 (23) 16 (21.7) 14 (19)

*

** Toughness of test coupon removed from detail after commercial vacuum hardening; minimum double tempered (triple tempered preferred) to 44/46 HRC.

Capability toughness after oil quench and minimum double temper (triple tempered preferred) to 44/46 HRC

Hardening Temperature

"Annealed" Steel Capability CVN*,

ft-lbs (J)

"Class 1" Hardened Steel CVN**, ft-lbs (J)



Die Materials Specification Task GroupDie Materials Specification Task GroupStep Heating

• Load work into cold furnace, and heat at a rate not to exceed 400°F/hr. (220°C/hr.)

• Heat to 1000° F to 1250° F (540°C-675°C)

• Hold until Ts-Tc < 200°F (110°C)

• Heat to 1550° F ± 50°F (845°C ± 28°C )

• Hold until Ts-Tc < 100°F (55°C) heat in “steps” holding

• Alternative preheating steps may be used at the discretion of heat treater or toolmaker.

• Rapidly heat to the designated austenitizing temperature (see Table 2)

• The outside of the tool heats up faster than the inside. This creates stress due to thermal expansion and phase changes.

• Aim to reach austenitizing temperature with the outside and inside temperatures as close as possible.

• This can be achieved by heating slowly but it is more efficient to heat in “steps” holding temperature constant so that equalization can occur.

• Use the heating cycle which gives the least risk and is compatible the equipment available.

• The most sensitive temperatures are when the temperature reaches the “critical” temperature of 1560°F (850°C) and close to austenitizing temperature where grain growth can occur.

Soaking Times • With inserted thermocouples soak time shall be 30 minutes after Ts-Tc < 25°F (14°C), or 90 minutes maximum after Ts=designated

hardening temperature, whichever occurs first.

Good heating practice means that soaking is more effective. Soaking is performed partly to equalize tool temperature but principally to dissolve carbides and increase effective alloy content of the matrix. This does not start until close to austenitizing temperatures. Too long a soak time increases the risk of sagging and can cause grain growth. A more common fault is too little soaking.



NADCA Grade

Tradename Type Hardening Temp, °F (°C)

A Type H13 - Premium A1885 1885 (1030)

B Type H13 - Superior B1885 1885 (1030)

C Type 2367 & ModifiedUddeholm Dievar C1850 1850 (1010)Böhler W403 VMR C1885 1885 (1030)Ellwood ExELL Hot Die C1885 1885 (1030)Kind RPU C1885 1885 (1030)Thyrotherm 2367 C1885 1885 (1030)

D Type H11 / 2343Bohler W300 Isobloc D1830 1830 (1000)Thyrotherm 2343 Supra D1830 1830 (1000)Uddeholm Vidar Supreme D1830 1830 (1000)

E Type H11 ModifiedBohler W400 VMR E1810 1810 (990)Uddeholm Vidar Superior E1825 1825 (995)Kind TQ-1 E1850 1850 (1010)Thyrotherm E38K E1850 1850 (1010)Aubert & Duval ADC3 E1885 1885 (1030)Dunn DSS#3 E1885 1885 (1030)Ellwood ExELL Tuf-Die E1885 1885 (1030)Nippon Koshuha KDA-1 E1885 1885 (1030)

Cross Reference Guide to Special Quality Die Steels


NADCA Grade

Tradename Type Preheating Temp, °F (°C)Hardening Temp,

°F (°C)

A Type H13 - Premium A18851100-1250 (595-675) 1500-1560 (815-850)

1885 (1030)

B Type H13 - Superior B18851100-1250 (595-675) 1500-1560 (815-850)

1885 (1030)

C Type 2367 & Modified

Uddeholm Dievar C18501100-1200 (595-650) 1500-1560 (815-850)

1850 (1010)

Böhler W403 VMR C1885930-1020 (500-550) 1375-1475 (745-800)

1885 (1030)

Ellwood ExELL Hot Die C18851100-1200 (595-650) 1475-1525 (800-830)

1885 (1030)

Kind RPU C18851100-1200 (595-650) 1500-1560 (815-850)

1885 (1030)

Thyrotherm 2367 C18851100-1200 (595-650) 1500-1560 (815-850)

1885 (1030)

D Type H11 / 2343

Bohler W300 Isobloc D18301100-1200 (595-650) 1500-1560 (815-850)

1830 (1000)

Thyrotherm 2343 Supra D18301100-1200 (595-650) 1500-1560 (815-850)

1830 (1000)

Uddeholm Vidar Supreme

D18301100-1200 (595-650) 1500-1560 (815-850)

1830 (1000)



NADCA Grade

Tradename Type Preheating Temp, °F (°C)Hardening Temp,

°F (°C)

E Type H11 Modified

Bohler W400 VMR E1810930-1020 (500-550) 1375-1475 (745-800)

1810 (990)

Uddeholm Vidar Superior E18251100-1200 (595-650) 1500-1560 (815-850)

1825 (995)

Kind TQ-1 E18501100-1200 (595-650) 1500-1560 (815-850)

1850 (1010)

Thyrotherm E38K E18501100-1200 (595-650) 1500-1560 (815-850)

1850 (1010)

Aubert & Duval ADC3 E1885 1375-1425 (745-775) 1885 (1030)

Dunn DSS#3 E1885 1275-1325 (690-720) 1885 (1030)

Ellwood ExELL Tuf-Die E18851100-1200 (595-650) 1450-1500 (790-815)

1885 (1030)

Nippon Koshuha KDA-1 E18851100-1200 (595-650) 1475-1525 (800-830)

1885 (1030)



Possible NADCA Sponsored Projects:

• Impact toughness & thermal fatigue resistance of the new grades listed in #207-2006

Project 161: Thermal Fatigue Resistance of High Performance Die Steels

Project Description: The objective is to provide the Die Materials Specifications and Heat Treating Task Force with detailed thermal fatigue and Charpy V-notch behavior of the advanced die steels that are included in NADCA 207-2006. Whereas data was provided by the suppliers of the steels, more testing of these steels is needed to strengthen the Specification and promote implementation by the die casting industry.

• 8 thermal fatigue samples and 80 CVN samples will be machined from select steels (two TF and ten Charpy samples per steel type) and quenched according to the specification. The as-quenched and the tempered microstructures will be determined. The thermal fatigue resistance of the eight specimens and the Charpy V-notch impact strength will be evaluated.

$25K



•Comparative study of heat checking resistance between Premium Grade H13 with lower bainitic and martensitic structures Project 160: A COMPARATIVE STUDY OF HEAT CHECKING RESISTANCE BETWEEN P.G. H13 STEEL WITH LOWER BAINITIC AND MARTENSITIC STRUCTURES

• Project Description: Eight H13 immersion thermal fatigue specimens quenched then dunk tested:

• Oil quenched to 150F

• Cooled rapidly in a 5 bar vacuum furnace to 150F

• Cooled rapidly in a 5 bar vacuum furnace to 650F, held for five hours and cooled to 150F

• Vacuum quenched in a 5 bar furnace to 590F, held for five hours and cooled to 150F.

• As-quenched and double tempered microstructures will be determined.

• The differences in the thermal fatigue resulting from the isothermal hold temperatures during quenching will provide a range of microstructures to determine the effect on thermal fatigue behavior to show the relationship between the different types of heat treatments, microstructures and their effect on thermal fatigue behavior.

$25K



• Capability impact toughness of advanced die steels at oil quenched at tempered hardness “other than” 44/46HRC

• ~$50K - $100K

• Commercially hardened impact toughness of advanced die steels at hardness “other than” 44/46HRC

•~$25K

• Optimization of the tempering time/temperature process

• $ ?

Documents

Conducted by the Die Materials Specification Subcommittee October 16th & 17th, 2007 Die Materials Specification Task Group Die Steel Quality & Heat Treatment