Patent ID: 8968495
Filing Date: 2015-03-03
Classification: B21D,B21J,B21K,B22F,B26F,B32B,C21D,Y10T

Abstract:
1. A method of thermo-mechanically processing a preform composed of tool steel having a martensitic start temperature and a stable austenitic temperature, the preform having a first region and a second region proximate the first region, each of the first and second regions containing austenite, and the first region including an outer surface, a plurality of outer dimensions for the outer surface, and a microstructure, the method comprising: establishing at least the first region of the preform at a process temperature between the martensitic start temperature and the stable austenitic temperature; while the first region of the preform is at the process temperature, deforming the first region without deforming the second region to change at least one of the outer dimensions of the first region and to modify the microstructure of the first region over a depth extending from the outer surface to a depth of after the first region is deformed, cooling the first region to room temperature, wherein the microstructure in the first region includes martensitic grains having a distribution of misorientation angles characterized by an average misorientation angle that is greater than an average misorientation angle from heat treating without deforming and differs in at least one microstructural characteristic from the second region.