Patent ID: 6531007
Filing Date: 2003-03-11
Classification: C21D

Abstract:
A method for the manufacture of a steel product comprising the steps of:(a) subjecting the steel to precipitation hardening in a martensitic structure subsequent to soft annealing; (b) shaping said steel, followed by solution annealing between a temperature of 1050Â° C. and 1200Â° C. and for a time period of from 5 to 30 minutes; (c) quenching the steel from the solution annealing temperature to a temperature below 500Â° C. with a quenching rate of at least 5Â° C. per second, said quenched steel being subjected to an isothermal martensitic transformation; and (d) hardening at a temperature between 450Â° C. and 550Â° C. for at least 3 minutes to cause particles to precipitate out from solution into the martensitic structure.