Microstructural evolution during laser cladding of M2 high-speed steel

Niu, Hong‐Ying; Chang, I.T.H.

doi:10.1007/s11661-000-0206-z

Cited by 40 publications

(18 citation statements)

References 20 publications

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“…This mainly martensitic structure is also in general agreement with the results obtained by Niu and Chang [29] for another tool steel, M2, and layer thicknesses in the range 0.3-1.0 mm. The amount of austenite found in walls made from both types of powder indicates that it does not readily completely decompose at the temperatures that the deposited layers are reheated to.…”

Section: Discussionsupporting

confidence: 91%

Direct additive laser manufacturing using gas- and water-atomised H13 tool steel powders

Pinkerton¹,

Li²

2004

Int J Adv Manuf Technol

102

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To date only gas-atomised tool steel powders have been used for direct laser additive manufacturing and the potential benefits of using water-atomised powders have not been explored. As the use of the process in the rapid tooling field is growing, there is a need to explore if the less expensive wateratomised materials can be realistically utilised. A comparative investigation is described, using gas-and water-atomised H13 powder deposited with a CO 2 laser and coaxial powder feed nozzle. Multiple layer wall dimensions, composition, microstructure, surface finish and hardness are related to process conditions and the causes of the observed phenomena are discussed. An energy-balance method is used to model the temperature of the powders and the results used to explain some of the effects. Results indicate that using the lower cost water-atomised powder still allows a metallurgically sound component to be built and does not significantly affect surface finish. The build rate is, however, lower and the water-atomised powder tends to produce slightly softer walls, attributable to a higher temperature during tempering of deposited material by subsequent laser passes.

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Section: Discussionsupporting

confidence: 91%

Direct additive laser manufacturing using gas- and water-atomised H13 tool steel powders

Pinkerton¹,

Li²

2004

Int J Adv Manuf Technol

102

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“…Además, se puede apreciar una transición entre la microestructura de tipo eutéctico muy fino en la parte inferior (detalle 2_2) hasta una precipitación más rica en carburos en la parte superior (detalle 2_1). Este efecto es debido a la mayor temperatura alcanzada conforme se asciende hacia el recubrimiento y un mayor tiempo de enfriamiento [9][10][11][12] .…”

Section: A R a C T E R I Z A C I ó N D E L O S Recubrimientosunclassified

“…El análisis de la influencia de los parámetros muestra que la cantidad de austenita está fuertemente condicionada por la energía específica aportada (P/VD) que condiciona la velocidad de enfriamiento. A menor energía aportada, mayor cantidad de austenita retenida [9][10][11][12] . El análisis del cordón depositado con una energía de 20 J/mm 2 muestra un mayor contenido en austenita hasta el 57 % (Tabla VI).…”

Section: A R a C T E R I Z A C I ó N D E L O S Recubrimientosunclassified

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Problemas en la reparación por <i>laser cladding</i> de superficies de acero AISI D2 tratado térmicamente

Candel¹,

Amigó²,

Ramos³

et al. 2010

REVMETAL

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ResumenSe ha depositado polvo de acero de herramienta (H13) sobre diferentes sustratos de acero que se encuentran en estado metalúrgico diferente (recocido o de temple y revenido) para comparar los resultados y se ha analizado la microestructura del recubrimiento y de la zona afectada por el calor (ZAC) mediante microscopia óptica, microscopía electrónica de barrido (MEB) y difracción de electrones retrodispersados (EBSD). El objetivo del trabajo es relacionar los parámetros del proceso de recubrimiento por láser (potencia, velocidad, caudal de polvo) con las transformaciones metalúrgicas producidas en el acero de herramienta AISI D2, con el fin de optimizar las condiciones de operación durante la reparación. Los resultados muestran que los parámetros influyen en gran medida en la geometría del cordón y en la formación de la microestructura. Aunque es sencillo obtener deposiciones geométricamente aceptables (forma y tamaño adecuado, ausencia de porosidad), en muchos casos aparecen fenómenos perjudiciales como la dilución de carburos y la aparición de fases metaestables que modifican las propiedades mecánicas del recubrimiento. En concreto, la presencia de austenita retenida en el recubrimiento, relacionada con la temperatura má-xima alcanzada y la velocidad de enfriamiento, produce una fuerte disminución en la dureza, que debe evitarse. Además, para una misma composición y acabado superficial, el estado metalúrgico inicial del sustrato tiene una gran influencia sobre el resultado. Sustratos en estado de temple implican una mayor absorción del láser y la acumulación de calor que produce mayores zonas afectadas por el calor (ZAC). Por ese motivo, deben optimizarse los paráme-tros del proceso para cada operación de manera que se mejore el comportamiento en servicio del componente. Palabras claveRecubrimiento láser; Acero de herramienta; EBSD; Austenita; Microestructura. Problems in laser repair-cladding a surface AISI D2 heat treated tool steel AbstractThe aim of the present work is to establish the relationship between laser cladding process parameters (Power, Process Speed and Powder feed rate) and AISI D2 tool steel metallurgical transformations, with the objective of optimizing the processing conditions during real reparation. It has been deposited H13 tool steel powder on some steel substrates with different initial metallurgical status (annealed or tempered) using a coaxial laser cladding system. The microstructure of the laser clad layer and substrate heat affected zone (HAZ) was characterized by Optical microscopy, Scanning Electron Microscopy (SEM) and Electron Backscattered Diffraction (EBSD). Results show that the process parameters (power, process speed, feed rate …) determine the dimensions of the clad layer and are related to the microstructure formation. Although it is simple to obtain geometrically acceptable clads (with the right shape and dimensions) in many cases occur some harmful effects as carbide dilution and non-equilibrium phases formation which modify the mechanical properties of the coati...

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“…In the last decades, the research focus has been the optimization of mechanical properties and microstructures of components fabricated by LENS [7][8][9][10][11][12][13][14], and thermal modeling and control over the entire powder deposition process [15][16][17][18][19]. These investigations have provided a clear understanding of the characteristics of LENS and have promoted this technology as a major step towards actual industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Energy Consumption and Saving Analysis for Laser Engineered Net Shaping of Metal Powders

et al. 2016

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Abstract:With the increasing awareness of environmental protection and sustainable manufacturing, the environmental impact of laser additive manufacturing (LAM) technology has been attracting more and more attention. Aiming to quantitatively analyze the energy consumption and extract possible ways to save energy during the LAM process, this investigation studies the effects of input variables including laser power, scanning speed, and powder feed rate on the overall energy consumption during the laser deposition processes. Considering microhardness as a standard quality, the energy consumption of unit deposition volume (ECUDV, in J/mm 3 ) is proposed as a measure for the average applied energy of the fabricated metal part. The potential energy-saving benefits of the ultrasonic vibration-assisted laser engineering net shaping (LENS) process are also examined in this paper. The experimental results suggest that the theoretical and actual values of the energy consumption present different trends along with the same input variables. It is possible to reduce the energy consumption and, at the same time, maintain a good part quality and the optimal combination of the parameters referring to Inconel 718 as a material is laser power of 300 W, scanning speed of 8.47 mm/s and powder feed rate of 4 rpm. When the geometry shaping and microhardness are selected as evaluating criterions, American Iron and Steel Institute (AISI) 4140 powder will cause the largest energy consumption per unit volume. The ultrasonic vibration-assisted LENS process cannot only improve the clad quality, but can also decrease the energy consumption to a considerable extent.

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Microstructural evolution during laser cladding of M2 high-speed steel

Cited by 40 publications

References 20 publications

Direct additive laser manufacturing using gas- and water-atomised H13 tool steel powders

Direct additive laser manufacturing using gas- and water-atomised H13 tool steel powders

Problemas en la reparación por <i>laser cladding</i> de superficies de acero AISI D2 tratado térmicamente

Energy Consumption and Saving Analysis for Laser Engineered Net Shaping of Metal Powders

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