Process for the manufacture of a workpiece from a creep-resistant alloy

US4588552A · kind A · utility

Assignee

• BBC Brown, Boveri & Company Ltd. · CH

Inventors

• Gunther Schroder · Mannheim, DE
• Robert Singer · Erlangen, DE

Key dates

• Filing date: Nov 1, 1984
• Grant date: May 13, 1986
• Expiry date: Nov 1, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S29/031
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Manufacture of a workpiece from a creep-resistant nickel superalloy which is hardened by means of an oxide dispersion, by a powder-metallurgical process in which the mechanically alloyed powder is subjected to an isothermal or quasi-isothermal hot-rolling operation, in the course of which the powder particles are converted into a flake-shaped form with a pronounced longitudinal axes, and the rolled powder is introduced into a steel container and is compressed by isostatic hot-pressing. The workpiece is afterwards subjected to an annealing treatment which is designed to develop a coarse grain size. A preferred embodiment comprises the introduction of the powder into the mold or container in an oriented manner, in order to obtain a stratified packing of the powder, and an annealing treatment which is designed to develop a coarse grain size and is performed as a zone-annealing treatment.