Steel alloy, a holder or a holder detail for a plastic moulding tool, a tough hardened blank for a holder or holder detail, a process for producing a steel alloy

Abstract

A steel alloy is described that, in weight-%, includes 0.08-0.19 C, where 0.16≦C+N≦0.28, 0.1-1.5 Si, 0.1-2.0 Mn, 13.0-15.4 Cr, 0.01-1.8 Ni, 0.01-1.3 Mo, max. 0.7 V, max. 0.25 S, max. 0.01 Ca, max. 0.01 O, in order to improve the machinability of the steel, and balance iron and unavoidable impurities, wherein the steel alloy has a microstructure which, in a tough hardened condition, comprises a martensitic matrix with up to 30 vol-% ferrite.

1 . A steel alloy comprising, in weight-%:
 0.08-0.19 C,   0.16≦C+N≦0.28,   0.1-1.5 Si,   0.1-2.0 Mn,   13.0-15.4 Cr,   0.01-1.8 Ni,   0.01-1.3 Mo,   max. 0.7 V,   max. 0.25 S,   max. 0.01 Ca,   max. 0.0 O, in order to improve the machinability of the steel, and   balance iron and unavoidable impurities,   wherein the steel alloy has a microstructure which, in a tough hardened condition, comprises a martensitic matrix comprising up to 30 vol-% ferrite   
     
     
         2 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.09<C≦0.15. 
     
     
         3 . (canceled) 
     
     
         4 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.05-0.20 N. 
     
     
         5 . The steel alloy according to  claim 4 , wherein the steel alloy comprises more than 0.08 N and max 0.13 N. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . The steel alloy according to any of  claim 1 , wherein the total amount of C+N satisfies the condition 0.17<C+N≦0.25. 
     
     
         9 . (canceled) 
     
     
         10 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.6<Si≦1.2. 
     
     
         11 - 12 . (canceled) 
     
     
         13 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 1.30-1.65 Mn. 
     
     
         14 - 17 . (canceled) 
     
     
         18 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 13.5-14.5 Cr. 
     
     
         19 - 22 . (canceled) 
     
     
         23 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.20-0.50 Ni. 
     
     
         24 . (canceled) 
     
     
         25 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.15-0.25 Mo. 
     
     
         26 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.05-0.7 V. 
     
     
         27 - 30 . (canceled) 
     
     
         31 . The steel alloy according to  claim 1 , wherein the steel alloy comprises 0.10-0.15 S. 
     
     
         32 . (canceled) 
     
     
         33 . The steel alloy according to  claim 1 , comprising:
 0.09<C≦0.15,   0.08<N≦0.14,   wherein 0.17≦C+N≦0.25,   0.6-1.2 Si,   0.85-1.8 Mn,   13.5-14.8 Cr,   0.10-0.40 Mo,   0.1-0.55 Ni, and   0.05<V≦0.20,   wherein the steel alloy comprises a martensitic matrix, in a tough hardened condition, which contains up to 15 vol-% ferrite.   
     
     
         34 . The steel alloy according to  claim 1 , comprising:
 0.10-0.15 C,   0.08<N≦0.13,   wherein 0.8≦C+N≦0.25,   0.75-1.20 Si,   1.30-1.65 Mn,   13.6-14.5 Cr,   0.15-0.25 Mo,   0.30-0.55 Ni, and   0.05<V<0.15,   wherein the steel alloy comprises a martensitic matrix, in a tough hardened condition, comprising up to 10 vol-% ferrite.   
     
     
         35 - 38 . (canceled) 
     
     
         39 . The steel alloy according to  claim 1 , wherein the matrix comprises 0.05-6.5 vol-% ferrite. 
     
     
         40 . A process for producing at least one selected from a group comprising a holder base, a holder detail base, a molding tool base for a holder, a holder detail for a plastic moulding tool, and a molding tool, the process comprising:
 manufacturing a steel alloy comprising, in weight-%   0.08-0.19 C,   0.16≦C+N≦0.28,   0.1-1.5 Si,   0.1-2.0 Mn,   13.0-15.4 Cr,   0.01-1.8 Ni,   0.01-1.3 Mo,   max. 0.7 V,   max. 0.25 S,   max. 0.01 Ca,   max. 0.01 O, wherein the O, S, and Ca improve the machinability of the steel, and   balance iron and unavoidable impurities,   hot working an ingot of the steel alloy at a temperature range of 1100-1300° C.,   cooling the steel alloy, thereby hardening the steel alloy,   tempering the steel alloy twice for 2 hours at a temperature of 510-650° C., thereby obtaining a tough hardened blank having a martensitic matrix containing up to 30 vol-% ferrite.   
     
     
         41 . A process for producing at least one selected from a group comprising a holder base, a holder detail base, a molding tool base for a holder, a holder detail for a plastic moulding tool, and a molding tool, the process comprising:
 manufacturing a steel alloy with a chemical composition according to comprising, in weight-%   0.08-0.19 C.   0.16≦C+N≦0.28,   0.1-1.5 Si,   0.1-2.0 Mn,   13.0-15.4 Cr,   0.01-1.8 Ni,   0.01-1.3 Mo,   max. 0.7 V,   max. 0.25 S,   max. 0.01 Ca,   max. 0.01 O, wherein the O, S, and Ca improve the machinability of the steel, and   balance iron and unavoidable impurities,   hot working an ingot of the steel alloy at a temperature range of 1100-1300° C.,   cooling the steel alloy to an isothermal annealing temperature of 550-700° C., and   subjecting the steel alloy to the isothermal annealing at the isothermal annealing temperature for 5-10 h.   
     
     
         42 . The process of  claim 40 , wherein the steel alloy is produced, using scrap as a raw material, by melting the scrap in a furnace. 
     
     
         43 - 47 . (canceled) 
     
     
         48 . The process of  claim 41 , wherein the steel alloy is produced, using scrap as a raw material, by melting the scrap in a furnace. 
     
     
         49 . The process of  claim 41 , further comprising:
 hardening the steel alloy by austenitizing at a temperature of 900-1100° C. for 30 min, and   tempering the steel alloy twice for 2 hours at a temperature of 510-650° C.,   thereby obtaining a tough hardened blank having a martensitic matrix containing up to 30 vol-% ferrite.