Patent ID: 7416621
Filing Date: 2008-08-26
Classification: C21D

Abstract:
1. A method for rounding an annular part having an axis and an inside surface and an outside surface wherein the part is out of round due to non-uniform internal stresses, the method comprising: (a) measuring distances along reference lines from the axis to surface sections of of a reference surface of the annular part, the surface sections being associated with each reference line; (b) identifying a first surface section of the reference surface having an associated first distance along a first reference line from the axis to the first surface section greater than a second distance along a second reference line from the axis to a surface second section of the reference surface; and (c) introducing compressive stresses into a surface section of the inside surface, the surface section of the inside surface having a perimeter surrounding or adjacent an intersection of the first reference line and the inside surface, whereby the introduced compressive stresses cause deformation of the annular part thereby rounding the annular part, wherein the annular part comprises carbon steel, and wherein step (c) comprises heating to an austenitizing temperature the surface section of the inside surface, and allowing the heated surface section to quench to martensite thereby introducing compressive stresses into the surface section of the inside surface.