Digitalization: Laser Metal Deposition — The Future of Spare Parts and Repairs for Industrial Steam Turbines

2018 ◽  
Author(s):  
Norman Wittig
Keyword(s):  
Laser Welding ◽  
Turbine Blades ◽  
Welding Process ◽  
Spare Parts ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Steam Turbines ◽  
Detonation Spraying ◽  
Delivery Times ◽  
Laser Deposition Welding

Laser metal deposition (LMD) — also referred to as laser deposition welding — has been a well-established process for years. One example of its use is for tip repair for gas turbine blades from Siemens. The decision to also implement laser welding technology for the service of industrial steam turbines was based primarily on the fact that repairs — especially conventional welds and coatings including heat treatment and testing — are very time consuming and are very difficult to reconcile with the overhaul periods planned by customers. The robot supported automation of the LMD process and the fact of its lower heat input, reduced layer thicknesses and the resulting lowered deformation of the part due to reduced coating areas makes it possible to optimize lead times. The high level of process automation and reliability of a laser welding process represents another important benefit. Similarly, process parameters are constantly monitored and tracked, to ensure that the required quality standards are maintained and even increased. Furthermore, laser metal deposition completely replaced the conventional processes such as tungsten inert gas method (TIG), plasma transferred arc (PTA) and detonation spraying. In addition the technology unleashes now the possibility to repair and refurbish parts instead of new manufacturing, and therefore delivery times can be tremendously reduced. Based on the decision to six-axis robots it becomes possible enhancing the LMD process for complex 3D surfaces. After modeling a digital twin in Siemens NX CAM it is possible to generate, optimize and simulate the whole motion-sequences offline before starting the LMD process in the robot cell. So already designed parts in 3D-CAD can be used to develop the final robot program. In addition already existing technologies like 3D surface scanning will be implemented in the chain to support the LMD process. Digitalization turns from a buzzword to an established technology for industrial steam turbine manufacturing and repair.

Tribological comparison of Inconel 625 coatings deposited via laser metal deposition and tungsten inert gas welding process

2020 ◽  
Vol 32 (2) ◽  
pp. 022034 ◽  
Author(s):  
Rafael Gomes Nunes Silva ◽  
Adriano de Souza Pinto Pereira ◽  
Jurandir Marcos Sá de Sousa ◽  
Milton Pereira ◽  
Régis Henrique Gonçalves e Silva
Keyword(s):  
Welding Process ◽  
Metal Deposition ◽  
Inert Gas ◽  
Inconel 625 ◽  
Laser Metal Deposition ◽  
Tungsten Inert Gas Welding ◽  
And Tungsten

scholarly journals Influences of Cooling Conditions on the Liquation Cracking in Laser Metal Deposition of a Directionally Solidified Superalloy

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 466 ◽  
Author(s):  
Baohua Chang ◽  
Shuo Yang ◽  
Guan Liu ◽  
Wangnan Li ◽  
Dong Du ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Turbine Blades ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Directionally Solidified ◽  
Liquation Cracking ◽  
Material Loss ◽  
Cooling Conditions ◽  
Conventional Cooling ◽  
Forced Cooling

Directionally solidified (DS) nickel-based superalloys are widely used in manufacturing turbine blades, which may fail due to wear and/or material loss during service. Laser metal deposition (LMD) has been considered to be a promising technology in repairing the damaged components thanks to the high temperature gradient formed, which is conducive to the growth of directional microstructure. Intergranular liquation cracking in the heat-affected zone (HAZ) has been one of the major problems in LMD of the DS superalloys. In this paper, the influences of two cooling conditions (conventional cooling and forced cooling) on the microstructure development and liquation cracks were studied for the laser deposition of a DS superalloy IC10. The experimental results showed that, as compared to the conventional cooling, both number and length of the liquation cracks in HAZ were notably reduced under the forced cooling condition. The effects of cooling conditions on temperature and stress fields were analyzed through a thermo-elastoplastic finite element analysis. It was revealed that the maximum tensile stress and high tensile stress region in the substrate were effectively minimized while using the forced cooling measure. The forced cooling on the substrates is a promising method for mitigating the liquation cracking in LMD of DS superalloys.

Blades and Vanes Platform Laser Rebuilding

2020 ◽  
Author(s):  
A. Gabrielli ◽  
M. Moretto
Keyword(s):  
Single Crystal ◽  
Gas Turbines ◽  
Structural Integrity ◽  
Turbine Blades ◽  
Metal Deposition ◽  
Inert Gas ◽  
Automatic Process ◽  
Laser Metal Deposition ◽  
Tungsten Inert Gas Welding ◽  
Crystal Material

Abstract The evolution of industrial gas turbines towards increased efficiency and performance requires ever higher operating temperatures for the engines. In order to remain competitive in the market, OEM companies continuously need to develop maintenance programs and reconditioning technologies able to extend the life of these components as much as possible. During the operation, turbine blades and vanes are prone to deterioration due to the high temperature of the gas passing along the platform surface, causing hot corrosion and thermomechanical fatigue. In particular, this results in deterioration and crack formation at platform edges. If oxidized, cracked or otherwise deteriorated locations are found during service inspections, the component platform has to be rebuilt. The standard method for rebuilding the platform is to remove the deteriorated material volume and rebuild it by welding. In particular, the most common welding method for rotor blades and stator vanes restoration today is the tungsten inert gas welding (GTAW). However, tungsten inert gas welding has a large heat affected zone, which can later lead to major distortion, due the elevated thermal input, and loss of structural integrity of the reconditioned part. In particular, for single crystal material high thermal input can promote recrystallization issues and this phenomenon compromises the mechanical properties and considerably reduces the life of the component. The most recent reconditioning techniques developed by Ansaldo Energia involves the use of laser metal deposition technology to rebuild the damaged areas and restore the platform to the original shape. Prior to the automated process the area, on which the clad will be laid, requires precise preparation. This paper describes a customized, automatic process to restore the deteriorated blade or vane area by the laser metal deposition technique for equiaxial or single crystal material, minimizing the thermal input and resulting in high resistance rebuilding.

Microstructural Characterization of the Laser Welding in a Nickel Based Superalloy

MRS Advances ◽  
2019 ◽  
Vol 4 (63) ◽  
pp. 3463-3473
Author(s):  
Mayra Jurado ◽  
Gerardo Altamirano ◽  
Jorge Leobardo Acevedo ◽  
Alvaro Aguirre
Keyword(s):  
Heat Treatment ◽  
Laser Welding ◽  
Turbine Blades ◽  
Base Material ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Heat Treatment Condition ◽  
Nickel Base Superalloy ◽  
Micro Laser Welding ◽  
Laser Welding Process

ABSTRACTIn this research it was experimentally analyzed the effect of the parameters of the Pulsed Micro Laser Welding Process Nd:YAG on the microstructural behavior of a nickel base superalloy (IN-738). For this purpose, different laser welding tests were performed on samples subjected to different heat treatment conditions obtained from the gas turbine blades. The influence of the power and the speed welding of the applied process and heat treatment condition on the weld geometry, microstructure and mechanical properties was determined. The microstructures of the obtained welds were characterized by scanning electron microscopy and Vickers hardness tests. In general, alternatives to homogenize and rejuvenate the microstructure of the base material are proposed in order to avoid the formation and propagation of cracks. The results are discussed mainly in terms of the present phases and decomposition of carbides, which considerably affect the weldability of the IN-738 superalloy. This study provides useful information for the subsequent restoration of the 2nd step turbine blades by using of the Laser Welding Process Nd:YAG.

Integration of pure copper to optimize heat dissipation in injection mould inserts using laser metal deposition

2021 ◽  
Vol 33 (1) ◽  
pp. 012029
Author(s):  
Stefan Polenz ◽  
Christian Kolbe ◽  
Florian Bittner ◽  
Elena López ◽  
Frank Brückner ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Pure Copper ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Injection Mould
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