Selective Laser Melting of Duplex Stainless Steel 2205: Effect of Post-Processing Heat Treatment on Microstructure, Mechanical Properties, and Corrosion Resistance.

Papula Papula,Easton Easton,Chen Chen,Virkkunen Virkkunen,Hänninen Hänninen,Pateras Pateras,Song Song,Yagodzinskyy Yagodzinskyy,Brandt Brandt

doi:10.3390/ma12152468

Papula Papula, Easton Easton + Show 7 more

Open Access

https://doi.org/10.3390/ma12152468

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Journal: Materials	Publication Date: Aug 2, 2019
Citations: 80	License type: CC BY 4.0

Affiliation: RMIT University, Aalto University

Abstract

Additive manufacturing (AM) is a rapidly growing field of technology. In order to increase the variety of metal alloys applicable for AM, selective laser melting (SLM) of duplex stainless steel 2205 powder and the resulting microstructure, density, mechanical properties, and corrosion resistance were investigated. An optimal set of processing parameters for producing high density (>99.9%) material was established. Various post-processing heat treatments were applied on the as-built predominantly ferritic material to achieve the desired dual-phase microstructure. Effects of annealing at temperatures of 950 °C, 1000 °C, 1050 °C, and 1100 °C on microstructure, crystallographic texture, and phase balance were examined. As a result of annealing, 40–46 vol.% of austenite phase was formed. Annealing decreased the high yield and tensile strength values of the as-built material, but significantly increased the ductility. Annealing also decreased the residual stresses in the material. Mechanical properties of the SLM-processed and heat-treated materials outperformed those of conventionally produced alloy counterparts. Using a scanning strategy with 66° rotation between layers decreased the strength of the crystallographic texture. Electrochemical cyclic potentiodynamic polarization testing in 0.6 M NaCl solution at room temperature showed that the heat treatment improved the pitting corrosion resistance of the as-built SLM-processed material.

Highlights

IntroductionMaterials performance is often a factor that limits available technological designs and solutions
Materials performance is often a factor that limits available technological designs and solutions.Advances related to manufacturing methods and processes enable the development of high-performance metallic materials
Preliminary tests for establishing suitable Selective laser melting (SLM) processing parameters for 2205 duplex stainless steel suggest that a sufficiently high laser power, 250 W, should be used to minimize porosity

Summary

Introduction

Materials performance is often a factor that limits available technological designs and solutions. Advances related to manufacturing methods and processes enable the development of high-performance metallic materials. Additive manufacturing (AM) technology offers many possibilities for localized microstructural control and material design [1,2,3,4]. Metal AM has grown significantly over the past decades and evolved into an industrial-scale manufacturing technique to enable the production of functional and structural components, of virtually any geometry, with high efficiency and accuracy. Selective laser melting (SLM), a powder bed fusion technique, is widely used for AM processing of metallic alloys.

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