Patent ID: 6051203
Filing Date: 2000-04-18
Classification: C23C,Y10T

Abstract:
A method for making a magnetite structure comprising providing a structure consisting essentially of plain steel having a plurality of surfaces, transforming the plain steel structure to a hematite structure, having a predetermined size, shape and wall thickness, by heating the plain steel structure in an oxidative atmosphere having an oxygen source consisting essentially of free oxygen at a temperature between about 750.degree. C. and about 1200.degree. C. to uniformly and substantially completely oxidize the plain steel structure, the hematite structure being monolithic and retaining substantially the same physical shape as the plain steel structure, and then de-oxidizing the hematite structure to a magnetite structure by heating the hematite structure in a vacuum between about 1000.degree. C. to about 1300.degree. C., wherein the magnetite structure retains substantially the same shape, size and wall thickness as the hematite structure and a monolithic magnetite structure is produced.