Methods for processing nanostructured ferritic alloys, and articles produced thereby

Abstract

A method of forming an article including a nanostructured ferritic alloy is provided. The method provides steps for substantially inhibiting grain growth of a workpiece that includes nanostructured ferritic alloy, during heating and deforming at high temperatures and at high strain rates. Advantageously, the article is formed via conventional high strain rate techniques and thus, cost savings are provided. Articles are also provided which are formed by the method, and the articles so produced exhibit good mechanical properties at high operating temperatures, and thus are utilized as turbomachinery components, and in particular, component of a heavy duty gas turbine or steam turbine. A turbomachinery component comprising an NFA is provided.

Description

BACKGROUND[0001]The present disclosure relates to nanostructured ferritic alloys (NFAs), and more particularly, methods for processing the same utilizing high temperature processing methods. The disclosure also relates to an article comprising a nanostructured ferritic alloy (NFA) that is formed by using such a method.[0002]Gas turbines operate in extreme environments, exposing the turbine components, especially those in the turbine hot section, to high operating temperatures and stresses. In order for the turbine components to endure these conditions, they are necessarily manufactured from a material capable of withstanding these severe conditions. In other words, a material used for the turbine components limits the temperature range that can be used without inducing a significant degradation in the mechanical properties of the material.[0003]Superalloys have been used in these demanding applications because they maintain their strength at up to 90% of their melting temperature an...

AI Technical Summary

Benefits of technology

The patent describes a method for making a component using a nanostructured ferritic alloy. The method involves introducing strain into the material at a low temperature to prevent grain growth during a subsequent heating and deforming process. This results in a more uniform and higher quality material. The method can be used to make turbomachinery components that have improved performance.

Problems solved by technology

Gas turbines operate in extreme environments, exposing the turbine components, especially those in the turbine hot section, to high operating temperatures and stresses.

However, use of conventional steels is often limited in high temperature and high stress applications because they fail to meet necessary mechanical property requirements and / or design requirements.

), typically leads to a change in its final microstructure and thus results in the degradation of its mechanical properties.

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