ALTA 1.2344 Tool Steel Properties (X40CrMoV5-1, H13)

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Hot work tool steel

ALTA 1.2344 Tool Steel Specification

Steel properties

ALTA 1.2344 steel is a kind of ~ 5% chromium hot work tool steel, be widely used in global markets. This steel have high hot toughness, high hot hardness (red hardness) and high resistance agianst heat-cracking.

High firmness during the heat and high resistance to the tempering and the wear (higher than 1.2343 steel), very good toughness and plastic properties during normal or high temperatures.
(** its tensile strength at 600-650°C, high temperature hardness, impact toughness, thermal stability, and thermal fatigue resistance at 750°C are all good)

On the other hand, its high-temperature impact toughness, thermal wear resistance, oxidation resistance at 600°C and 1000°C, fatigue resistance at 750°C, and cutting and forge ability are all better than 1.2581/AISI H21 tool steel.

Applications

² Die-casting mold (mold core, insert, mold core, diverter cone, nitrided ejector pin)

² Extrusion die (mold core, die pad, flow block)

² Hot pressing molds for aluminum, copper, magnesium

² Cold stamping, hot shearing, compression rings and wear-resistant parts

² Hammer forging die, press forging die

Chemical composition

Chemical Composition per %

	C	Si	Mn	P	S	Cr	Mo	V	Ni	Cu
Min.	0.35	0.80	0.25			4.80	1.20	0.85
Max.	0.42	1.20	0.50	0.025	0.010	5.50	1.50	1.15	0.25	0.30

Basic melting process :

IM/EAF + LF + VD + (ESR)

Hardness :	Max 229 HB (annealed)
Reduction ratio :	5 : 1 minimum or required
Grain size :	≥ 6.0 per ASTM E112
Non-metallic inclusion :	≤ 1.0 (thick), ≤ 1.5 (thin) per ASTM E45 method A (more pure by ESR route)
Microstructure	SEP1614 or NADCA # 207
Ultrasonic Test	SEP1921, EN 10308, ASTM A388 or agreed methods
Macro-structure	As per ASTM E381
Straightness / flatness	≤ 1.5 mm / m (machined), ≤ 2.5 mm / m (black)
Tolerance	Per discussed
Size range (round bars)	Ø 12 - 800 mm
Size range (flats, plates)	8 - 600 mm in thickness max. 1100 mm in width

Heat treatment

Annealing	Temperature(°C)	Hardness
Annealing	750 - 780	max. 229 HB

Hot-forming	Temperature(°C)
	900 - 1100

Hardening and tempering	Quenching temperature(°C)	Quenching medium	Frequently-used tempering temperature(°C)
Hardening and tempering	1010 - 1030	Oil or air-cooled	540 - 560

Ac1	Ac3	Ar1	Ar3	Ms
860	915	775	815	340

Elastic modulus : E ( N/mm2 )

Temperature °C	Room 20	300	500	700
E	21000	19500	17000	10000

Coefficient of thermal conductivity : λ W/(m·K)

Temperature °C	Room 20	650
λ	32.23	28.90

Coefficient of linear expansion : α(mm/(mm·°C))

Temperature °C	20~100	20~200	20~300	20~400	20~500	20~600	20~1000
Αx 10-6	9.10	10.30	11.50	12.20	12.80	13.20	13.50

Oxidation resistance : (test sample hardness 47.0~48.0 HRC), + g/m2

h	2	7	15	25	35	45	60	80	125	150
600 °C	0.3	0.3	0.8	0.8	0.8	0.9	1.0	1.0	1.9	2.1

** The oxidation resistance of ALTA 1.2344 steel is better than ALTA 1.2581/AISI H21 steel at 600°C x 150h, and its oxidation weight gain is Reduced by 32.5g/m2 . But a little worse than ALTA 1.2343 steel (0.g/m2 higher).

h	750 °C	h	750 °C
2	6.5	25	76.0
5	15.2	30	87.0
8	26	35	96.8
11	37.6	40	106.2
15	49.5	45	116.2
20	63.5	50	127.3

** The oxidation resistance of ALTA 1.2344 steel is worse than ALTA 1.2581/AISI H21 and ALTA 1.2343/AISI H11 steel at 750°C x 50h, and its oxidation weight gain is higher by 6.2g/m2 and 81.4g/m2 respectively.

H	1	2	3	4
1000 °C	96.7	218	339	429

** The oxidation resistance of ALTA 1.2344 steel is better than ALTA 1.2581/AISI H21 and ALTA 1.2343/AISI H11 steel at 1000°C x 4h, and its oxidation weight gain is reduced by 134.5g/m2 and 31.0g/m2 respectively.

Thermal stability (-HRC) (A=47.0~48.0 HRC, B=43.7~44.2 HRC)

(1) 620°C

Soaking time (h)	A	B	Soaking time (h)	A	B
0	47.5	43.5	11.5	38.0	36.7
2	43.1	41.5	14.5	37.4	35.4
4	42.8	40.2	17.5	35.5	33.9
6	41.4	38.0	21	33.3	33.0
8	39.7	36.80

** Under the same a, b hardness conditions, the thermal stability of ALTA 1.2344 tool steel at 620°C for 2-21 hours is lower than ALTA 1.2581/H21 tool steel, and its hardness difference is Lower 6.2 and 4.6 HRC respectively. But, under A hardness, the thermal stability of ALTA 1.2344 steel of 2-21h hours is higher than ALTA 1.2343 steel 1 - 4.6HRC. Along with the soaking time increased, the difference range decreased, and it is only 1HRC at up to 21h.

(2) 660°C

Soaking time (h)	A	B	Soaking time (h)	A	B
0	47.6	43.7	5	31.2	30.8
1	39.4	37.8	7	29.8	30.2
2	35.7	34.4	9	29.4	28.4
3	33.6	32.3	12	27.4	27.6

** Under the same a, b hardness conditions, the thermal stability of ALTA 1.2344 tool steel at 660°C for 1-12 hours is lower than ALTA 1.2581/H21 tool steel, and its hardness difference is Lower 4.6 and 3.1 HRC respectively. But, under A hardness, the thermal stability of ALTA 1.2344 steel of 1-12h hours is higher than ALTA 1.2343 steel 0.7 – 4.9 HRC. Along with the soaking time increased, the difference range decreased, and it is only 0.7HRC at up to 21h.

(3) 700°C

Soaking time (h)	0	0.5	1	1.5	2	3
A	47.5	33.8	31	28.3	27.7	-
B	43.0	33.4	31.5	30.1	28.1	28.2

** Under the same A hardness conditions, the thermal stability of ALTA 1.2344 tool steel at 700°C for 0.5-3 hours and B hardness conditions (for 3 hours) is lower than ALTA 1.2581/H21 tool steel, and its hardness difference is 5.0 and 2.1 HRC. But under A hardness condition (2 hours), its thermal stability is slightly higher than ALTA 1.2343 steel (0.7 HRC).