Cold work steel

1. Cold work steel in the hardened and tempered condition, manufactured powder metallurgically, having a wear rate of 8.3 mg/min, and having the following chemical composition in weight-%:

1.37% C

0.38% Si

0.37% Mn

4.81% Cr

3.50% Mo

0.1% W

357% V

max 0.3% S

0.064% N

balance iron and unavoidable impurities;

and a microstructure which in the hardened and tempered condition of the steel contains 6-13 vol-% of vanadium-rich MX-carbides,-nitrides and/or carbonitrides which are evenly distributed in the matrix of the steel, where X is carbon and/or nitrogen, at least 90 vol-% of said carbides, nitrides and/or carbonitrides having an equivalent diameter, D eq , which is smaller than 3.0 μm; and a total max. 1 vol-% of other existing carbides, nitrides or carbonitrides.

2. Steel according to claim 1 , wherein the matrix of the steel in the hardened condition of the steel essentially only consists of manensite, which contains 0.3-0.7% C in solid solution.

3. Steel according to claim 1 , wherein at least 98 vol-% of said MX-carbides, nitrides and/or carbonitrides have an equivalent diameter, D eq , which is smaller than 3.0 μm.

4. Steel according to claim 2 , wherein the steel, after hardening and tempering., has a hardness of 54-66 HRC.

5. Steel according to claim 4 , wherein the steel, after hardening and tempering, has a hardness of 60-63 HRC.

6. Steel according to claim 1 , wherein the steel contains 7-11 vol-% MX-carbides, nitrides and/or carbonitrides, where M consists substantially of vanadium and X is carbon and/or nitrogen.

7. Steel according to claim 6 , wherein the steel contains 9.5 vol-% MC-carbides.

8. Steel according to claim 1 , wherein the steel is manufactured powder metallurgically by manufacturing a powder of a molten metal and hot isostatic pressing the powder into a consolidated body.

9. Steel according to claim 8 , wherein the hot isostatic pressing is performed at a temperature between 950 and 1200° C. and at a pressure between 90 and 150 MPa.

10. Steel according to claim 8 , wherein the steel after hot isostatic pressing has been hot worked, starting at a starting temperature between 1050 and 1150° C.

11. Steel according to claim 9 , wherein the steel is hardened from a temperature between 940 and 1150° C. and tempered at a temperature between 200 and 250° C. or at a temperature between 500 and 560° C.

12. Steel according to claim 1 , wherein at least 90 vol-% of the MX-carbides, nitrides and/or carbonitrides have a maximal extension of 2.0 μm after hot isostatic pressing, hot working, soft annealing, hardening and tempering of the steel.

13. Cold work steel according to claim 1 wherein the steel has a ferritic matrix containing 8-15 vol-% MX-carbides, nitrides and/or carbonitrides, of which at least 90 vol-% have an equivalent diameter which is smaller then 3.0 μm, and max. 3 vol-% of other carbides, nitrides and/or carbonitrides after soft annealing and prior to hardening and tempering of the steel.

14. A tool for shearing, cuffing, blanking and/or metal forming of metallic working material in a cold condition of the material, or for pressing metal powder manufactured from a steel as claimed in claim 1 .

15. Steel according to claim 2 , wherein 0.4-0.6% C is in solid solution.

16. Steel according to claim 3 , wherein said equivalent diameter, D eq , is smaller than 2.5 μm.

17. Steel according to claim 4 , wherein after hardening and tempering the hardness is 58-63 HRC.

18. Cold work steel according to claim 13 wherein the equivalent diameter is smaller than 2.5 μm.