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1.2581 Hot Work Tool Steel

This alloy is one of the hot work, tungsten containing tool steels. The tungsten content is beneficial for hot strength at red heat, although toughness is somewhat reduced.

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Properties：

● High temperature resistance, wear resistance, excellent machining performance, strong stability in heat treatment, temperature up to 650℃ still works well.

Applications：

● Widely used in hot forging die, punching die and making nuts, bolts and other parts of the stamping die. It is also the first choice for forming die, scissors, hot extrusion die, top rod and lower die seat.

Parameters

Grade		Chemical Composition (%)
Grade		C	Si	Mn	Cr	V	P	S	W
GB	3Cr2W8V	0.30~0.40	≦0.40	≦0.40	2.20~2.70	0.20~0.50	≦0.03	≦0.03	7.50~9.00
ASTM	H21	0.26~0.36	0.15~0.50	0.15~0.40	3.00~3.75	0.30~0.60	≦0.03	≦0.03	8.50~10.00
DIN	1.2581	0.25~0.35	0.15~0.40	0.15~0.45	2.50~2.80	0.30~0.50	≦0.03	≦0.02	8.50~9.50
JIS	SKD5	0.25~0.35	0.10~0.40	0.15~0.45	2.50~3.20	0.30~0.50	≦0.03	≦0.02	8.50~9.50
Specification		Round BarØ (mm)						Flat Bar (mm)
		Hot Rolled		Hot Forged					EAF	ESR
		Ø12~Ø50		EAF		ESR		Thickness	20~200	20~450
		Ø12~Ø50		Ø50~Ø250		Ø50~Ø650		width	80~610	610max

Physical properties (average values) at ambient temperature

Modulus of elasticity [10³ x N/mm²]: 190-210

Density [g/cm³]: 7.80 Thermal conductivity [W/m.K]: 27.0

Electric resistivity [Ohm mm²/m]: 0.52

Specific heat capacity[J/g.K]: 0.46

Coefficient of Linear Thermal Expansion 10^-6 ^oC^-1

20-100^oC	20-200^oC	20-300^oC	20-400^oC	20-500^oC	20-600^oC	20-700^oC
11.5	12.0	12.2	12.5	12.9	13.0	13.5

Soft Annealing

Heat to 780-810^oC, cool slowly. This will produce a maximum Brinell hardness of 240.

Stress Relieving

Stress relieving to remove machining stresses should be carried out by heating to 650^oC, holding for one hour at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment.

Hardening

Harden from a temperature of 1080-1160^oC followed by air, oil or warm bath quenching. Hardness after quenching is 47-53 HRC.

Tempering Temperature (^oC) vs. Hardness (HRC)