Mat.No. 1.2581, DIN X30WCrV93, AISI H21

Designation by Standards

Chemical Composition (in weight %)

Description 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.  Applications Used for hot working dies and tooling such as die casting, extrusion and hot forming of parts. Pressure die casting tools, moulds for Cu and Cu-alloys. This grade is not used for water cooled tools.  Physical properties (avarage 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

Continuous Cooling Transformation (CCT) Diagram Click the image to enlarge the diagram. 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 Tempering temperature: See the table bellow. Tempering Temperature (^oC) vs. Hardness (HRC)

Tempering Diagram Click the image to enlarge the diagram. Forging Hot forming temperature: 1150-926^oC.  Machinability The tungsten content makes H21 somewhat difficult to machine. As compared to the W group of water hardening low alloy steels rated at 100% for machinability the H21 would rate 55%. Corrosion Resistance  This is a steel alloy and does not have corrosion resistance. It will rust unless given protective treatment. Welding  This alloy may be welded. Consult the supplier for details. Forms manufactured: Please see the  Dimensional Sales Program. Disclaimer The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values. Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his own evaluation and are not intended as warranties, either express or implied, of fitness for these or other puposes. There is no representation that the recipient of this literature will receive updated editions as the become available.