Title of Invention	STEEL ALLOY
Abstract	IN/PCT/2002/2030/CHE STEEL ALLOY The present invention relates to steel alloy, characterized in that it has a chemical composition, which contains in weight-%, 0.3-0.4 (C +N), wherein 0.16-0.27 C and 0.06-0.13 N 0.1 —1.5 Si 0.1—1.2 Mn 12.5 —14.5 Cr 0.5—1.7Ni 0.2—0.8 Mo 0.1—0.5 V Balance iron and unavoidable impurities from the manufacturing of the steel.

Full Text

TECHNICAL FIELD Then invention relates to a steel alloy and particularly to a steel alloy for the manufacturing of plastic moulding tools/The invention also concerns plastic moulding tools made of the steel and tough hardened blanks of the steel alloy for the manufacturing of plastic moulding tools. BACKGROUND OF Taffy INVENTION Plastic moulding tools are made of a great variety of steel alloys, such as carbon steels, low and medium alloyed steels, martensitic stdnless steels, precipitation hardening steels and macramé steels. A summary of existing steel alloys which are employed for the manicuring of plastic moulding tools can be found in the printed issue of Tool Sleds in the next Century, Proceedings of the international Conference on Tooling, September 29 to October 1,1999, University flabbier([SBN:3-9501105-0-X) page 635-642. Within the group of martensitic stainless steels there exist a number of commercial plastic moulding steels, including a steel that is manufactured and marketed by the applicant idler the legists-ed trade name STAVAX ESR® having the following nominal chemical composition in weight-%: 0.38 C, 0.8 Si, 0.5 Mn, 13.6 Cr, 0.3 V, balance iron and unavoidable impurities from the manicuring of the steel. That steed is standardized according to SIS2314 and AISI420. Steel of this rape has an adequate hardness in the hardened and tempered condition of the steel. The ductility (toques) and the harden ability, however, do not satisfy the increasingly higher demands which are raised on the materials of today for qualified plastic moulding steels, at least not for tools in large dimensions. DISCLOSURE OF THE It is a purpose of the invention to provide a martensitic stainless steel for plastic moulding tools having the same good features as STAVAX ESR® but an improved harden ability, i.e. capacity to be hardened also in large dimensions, and improved ductility (toughness). This can be achieved if the steel has the chemical composition which is stated in the appending patent claims. WE CLAIM: 1. Steel alloy, characterized in that it has a chemical composition, which contains in weight-%, 0.3-0.4 (C +N), wherein 0.16-0.27 C and 0.06-0.13 N 0.1 —1.5 Si 0.1—1.2 Mn 12.5 — 14.5 Cr 0.5—1.7Ni 0.2—0.8 Mo 0.1—0.5V balance iron and unavoidable impurities from the manufacturing of the steel. 2. The steel alloy as claimed in claim 1,wherein it optionally contains one or more of the elements S, Ca and O for the improvement of the mach inability of the steel, in amounts up to max. 0.15% S, max. 0.01% (100 ppm) Ca, and max. 0.01% (100 ppm)0. 3. The steel alloy as claimed in claim 1, wherein it contains 0.18-0.25%) C, preferably at least 0.20% C. 4. The steel alloy as claimed in claim 1, wherein it contains 0.10 %N. 5. The steel alloy as claimed in claim 1, wherein it contains max. 1.0 % Si, preferably max. 0.5 % Si. 6. The steel alloy as claimed in claim 1, wherein it contains max. 1.0 % Mn preferably max. 0.8 % Mn, suitably 0.3 —0.8 % Mn. 7. The steel alloy as claimed in claim 1, wherein it contains 13-14% Cr. 8. The steel alloy as claimed in claim 1, wherein it contains 1.0—1.5 %Ni, 9. The steel alloy as claimed in claim 1, wherein it contains max. 0.6 % Mo, preferably 0.3 — 0.4 % Mo. 10. The steel alloy as claimed in claim 1, wherein it contains 0.25 — 0.40 % V. 11. The steel alloy as claimed in any one of claims 1 to 10, wherein it contains 0.22% C 0.10% N 0.3 % Si 0.5% Mn 13.5% Cr 1.2% Ni 0.35 % Mo 0.35%V 12. The steel alloy as claimed in any one of claims 1 to 11, wherein it contains 0.07—0.15 % S but no intentionally added amount of calcium. 13. The steel alloy as claimed in any one of claims 1 to 11, wherein it optionally contains 0.025-0.15% S, 3-75 ppm Ca, preferably 5-40 ppm Ca, and 10-40 ppm. 14. The steel alloy as claimed in any one of claims 1 to 9, wherein it contains high contents of Cr, Mo and N that the amount of the elements Cr, Mo and N which are in solid solution in the matrix of the steel after hardening the steel from 1020°C followed by tempering at 250°C, 2 x 2h, i.e. are not bound in the form of carbides, nitrides, and/or cabinetries, is so great that the matrix of the steel has a PRE value which is at least 14.8, preferably at least 15.0, the PRE value being expressed through the formula: PRE = % Cr(s)+ 3.3 X % Mo (s)+ 20x % N(s), were Cr(s), Mo (s) and N (s) means Cr, Mo and N in solid solution in the matrix of the steel. 15. Tough hardened blank in the form of a bar, rod, plate or block for plastic molding tools and a plastic moldings tool characterized in that it is made of a steel alloy as claimed in any one of claims 1 to 14 having a microstructure, the matrix of which consists of tempered marten site and, in the matrix of the steel, totally 0.3-1.0 vol% primary precipitated cabinetries, which essentially completely consist of M(C,N) cabinetries.

Documents:

in-pct-2002-2030-che claims-duplicate.pdf

in-pct-2002-2030-che description (complete)-duplicate.pdf

in-pct-2002-2030-che-abstract.pdf

in-pct-2002-2030-che-claims filed.pdf

in-pct-2002-2030-che-claims grand.pdf

in-pct-2002-2030-che-correspondnece-others.pdf

in-pct-2002-2030-che-correspondnece-po.pdf

in-pct-2002-2030-che-description(complete) filed.pdf

in-pct-2002-2030-che-description(complete) grand.pdf

in-pct-2002-2030-che-drawings.pdf

in-pct-2002-2030-che-form 1.pdf

in-pct-2002-2030-che-form 18.pdf

in-pct-2002-2030-che-form 26.pdf

in-pct-2002-2030-che-form 3.pdf

in-pct-2002-2030-che-form 5.pdf

in-pct-2002-2030-che-other documents.pdf

in-pct-2002-2030-che-pct.pdf