Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels

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EP 2 090 383 A8

(12)	CORRECTED EUROPEAN PATENT APPLICATION
	Note: Bibliography reflects the latest situation

(15)	Correction information:
	Corrected version no 1 (W1 A1)

(48)	Corrigendum issued on:
	14.10.2009 Bulletin 2009/42

(43)	Date of publication:
	19.08.2009 Bulletin 2009/34

(21)	Application number: 09002103.1

(22)	Date of filing: 16.02.2009

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International Patent Classification (IPC):

B21D 37/00^(2006.01)
C21D 1/02^(2006.01)
C21D 8/00^(2006.01)

B21D 37/16^(2006.01)
C21D 7/13^(2006.01)
C21D 9/22^(2006.01)

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR
	Designated Extension States:
	AL BA RS

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Priority:

15.02.2008 US 29236 P

(71)	Applicant: Dayton Progress Corporation
	Dayton, OH 45449 (US)

(72)	Inventors:
	Shepard, Christon, L. Middletown OH 45042 (US) Turpin, David, L. Springboro OH 45066 (US) LaParre, Ronald, R. Centerville OH 45458 (US) Shaffer, Alan, L. Cincinnati OH 45248 (US) Chandrasekharan, Shrinidhi Dayton OH 45459 (US)

(74)	Representative: Beyer, Andreas
	Wuesthoff & Wuesthoff Patent- und Rechtsanwälte Schweigerstrasse 2 81541 München 81541 München (DE)

(54)	Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels

(57) A method of thermo-mechanically processing a preform (64) composed of tool steel and a tool (18) to modify a workpiece (28). The preform (64) has a region containing austenite. The method comprises establishing the region at a process temperature between a martensitic start temperature and a stable austenitic temperature. While at the process temperature, the region is deformed to change an outer dimension and to modify the microstructure to a depth of 1 millimeter or more. The tool (18) comprises a member (20) composed of tool steel. The member (20) includes a first region (30) that extends from the outer surface (22) to a depth of greater than 1 millimeter and a second region (32). The first region (30) includes a plurality of grains having an average misorientation angle greater than about 34°, an average grain size that is at least 10% smaller than the second region (30), and has a different grain orientation than the second region (30).