W.NR. 1.2581

Characteristics

Tungsten-chrome–vanadium steel for hardening in oil and possibly in air with very good hardenability, very high firmness during the heat and resistance to the tempering, high resistance to the hot tempering and good toughness. Further the steel has a lower resistance to tearing of thermal fatigue and higher sensitivity to quick changes of temperature. The steel is not appropriate for tools cooled by water. It is well-workable during the heat and well-workable in the soft-annealed state.

Suitability

For tools for hot mechanical working such as highly stressed small pressing dies and die inserts especially for die forging of accurate products from the difficult-workable steels and copper alloys, thorns and jaws for forging presses, forgings for swaging, tools for production of rivets, nuts and screws, small extrusion dies (matrixes), thorns, pressing discs for extrusion of alloys of non-ferrous metals. Further the firm and movable parts of molds, core and other small and highly stressed parts of molds for pressure casting of copper alloys can be made from the steel. Tools for hot cutting such as highly stressed small shear blades, punching dies, small trimming dies.

Comparable standards

DIN	W.Nr	AFNOR	AISI/ASIM	BS	JIS
X30WCrV-9-3	1.2581	~55NCD07-05	H-21	~224	SKD5

Chemical composition (typical; in weight %)

C	Si	Mn	P (max)	S (max)	Cr	W	V
0.25-0.35	0.10-0.40	0.15-0.45	0.035	0.035	2.50-3.20	8.00-9.00	0.30-0.50

Heat treatment of steel W.Nr. 1.2581

Way		Temperature [°C]	Procedure
Forging		900-1150	Cool slowly in air or better in dry ash or in other thermally-insulated material
Soft annealing		750-800	Warm few hours (according to the size of object), mostly four hours are enough and cool slowly in the furnace
Annealing to lower tension		600-650	Warm 1 to 2 hours and cool slowly in the furnace
Hardening		1100-1150	Cool in oil to the temperature of about 100 °C
		1120-1170	Cool bigger and difficult-shape tools in air or in thermal bath at the temperature of 500 – 550 °C
Tempering		550-650	Cool in air, the degree of tempering is set by hardness and toughness of instrument according to the tempering chart

Note

Chart of tempering values depending on the hardness:

°C	100	200	300	400	500	550	600	650	700
HRC	52	51	50	50	51	52	51	48	37
N/mm2	1790	1730	1690	1670	1730	1790	1730	1570	1170