Build-up Welding Method for Gas Turbine Components

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Solution Overview

Problem

Existing welding processes for gas turbine components face challenges in preventing strain age cracking and thermal degradation due to high temperatures, leading to reduced operational range and lifespan.

Innovation Solution

A method involving the deposition of a first molten material to form a boundary region on crack-sensitive fusion boundaries, followed by a second molten material application to create a filler region, providing resistance to strain age cracking and reducing heat input and base metal dilution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional welding processes are used to fabricate gas turbine components, then the components can be manufactured, but the weld joints suffer from strain age cracking and thermal degradation, reducing operational range and lifespan

Engineering Contradiction:

Improveresistance to strain age crackingVSAvoidoperational lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The welding process is divided into multiple passes with different material compositions. The first pass uses filler material matched to the base metal to create a sound weld, while subsequent passes use filler material designed to minimize strain age cracking susceptibility in the heat-affected zone. This segmentation of the welding process into functional zones addresses the contradiction by treating different regions with appropriate materials.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different filler materials are applied to different regions of the weld. The region adjacent to the base metal uses filler material optimized for metallurgical compatibility, while the cap region uses filler material optimized for crack resistance. This local differentiation of material properties resolves the contradiction between achieving sound weld metal and preventing strain age cracking.

Inventive Principle:

Principle #3Local quality

2Power

If high combustion temperatures are used to improve turbine efficiency, then energy efficiency increases, but thermal degradation of flow path materials occurs

Engineering Contradiction:

Improveturbine efficiencyVSAvoidthermal degradation

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The weld assembly functions as a composite structure with the base metal, weld metal, and heat-affected zone each having optimized properties. The heat-affected zone is treated with filler material that creates a composite microstructure with reduced susceptibility to thermal degradation and strain age cracking, allowing the component to withstand higher combustion temperatures without material failure.

Inventive Principle:

Principle #40Composite materials

3Reliability

If weld joints are made with increased resistance to strain age cracking, then operational range extends, but manufacturing complexity increases

Engineering Contradiction:

Improveresistance to strain age crackingVSAvoidwelding process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The welding process is planned and executed with preliminary preparation of the joint geometry and material selection. The first pass is designed to establish sound metallurgical bonding, and subsequent passes are pre-planned to build up crack-resistant cap material. This preliminary structuring of the welding sequence simplifies the overall process while achieving the dual goals of sound weld metal and crack resistance.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The approach results in a welded component with decreased stress levels, increased resistance to crack formation, and lower base metal dilution, extending the operational range and lifespan of gas turbine components.

Implementation Method 1

depositing a first molten material application onto a surface to form an at least partially solidified layer

Methodology Applied

Scientific EffectPhase change (melting and solidification): Phase Change

Implementation Method 2

depositing a first layer of weld metal on a worn surface of the component, whereby a heat-affected zone is created

Methodology Applied

Scientific EffectThermal heating: Heating

Data Source

PatentEP2537619B1Build-up welding method of fabricating a component and a manufactured component

Publication Date: 2020.02.12 GENERAL ELECTRIC CO

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AI summary

A method of fabricating a component (100) and a fabricated component are disclosed. The method includes depositing a material (202) to a component (100) and manipulating the material to form a boundary region (205) and a filler region (106) for desired properties. The component includes the boundary region (205) and the filler region (106), thereby having the desired properties.