Patent · US Expired

Expansion process for reducing the stresses in a seamless metal tube

US4174233A · kind A · utility

0Cited by
5References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 22, 1977
Grant dateNov 13, 1979
Priority date
Expiry dateSep 22, 1997

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/49805
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A process for reducing the residual stresses in a seamless metal tube which has undergone a straightening operation comprising subjecting the tube to an internal pressure of between 0.8 Pc and 1.0 Pc for a period of at least 3 minutes, while maintaining the temperature of the tube at or close to ambient temperature, Pc being the critical pressure beyond which the tube will undergo plastic deformation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.