Additive manufacturing by selective laser melting of stainless steel 316L with boron additions: evaluation of corrosion and wear properties

• Grant number: 19/01829-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2019
• End date: May 07, 2023
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Piter Gargarella
• Grantee: Gustavo Figueira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 16/11309-0 - The study, development and application of a hybrid process: Additive Manufacturing (AM) plus High Speed Machining/Grinding (HSM/G), AP.TEM

Abstract

Manufacturing processes where a part is built layer by layer are referred to as Additive Manufacturing (AM) processes. Among such processes used in the manufacturing of metallic parts, we can highlight the Laser Powder Bed Fusion (L-PBF) processes, in which a laser beam locally melts regions of a previously deposited powder layer. There are several process parameters for L-PBF, such as characteristics of the raw material used, power, speed, and scanning strategy of the laser beam, track overlap, and building direction of the part. Changes in these different parameters can induce microstructural changes and modify the properties of the part, mainly mechanical properties that are significantly affected by how the part is built. Among the most studied and accepted materials for additive manufacturing processes is stainless steel 316L. This steel usually forms an austenitic dendritic microstructure in conventional manufacturing processes, but a biphasic cellular microstructure (austenite and ferrite) has been observed during manufacturing by some AM processes. Stainless steel 316L is widely used in furnace parts, heat exchangers, jet engine parts, evaporators, in equipment for the chemical, pharmaceutical, and naval industries. Although this steel is known for its remarkable corrosion resistance, some industrial applications require a higher electrochemical response associated with high wear resistance. Studies indicate that it is possible to modify the chemical composition of stainless steel 316L to favor the formation of wear-resistant phases, but in return, it may reduce the concentration of alloying elements responsible for providing the alloy matrix with its high corrosion resistance. Given this, the objective of this project is to perform a systematic evaluation of the modification of the chemical composition of 316L steel manufactured by L-PBF and its effects on the tribological and electrochemical properties of the alloy. Parts will be manufactured using different process parameters (power, speed, and formed track overlap) using commercial powder to evaluate the process parameters that allow obtaining high density. The 316L alloy will then be modified to favor higher wear properties. From the modified alloy, metallic powder will be produced for the additive manufacturing process. Samples for wear and corrosion will be manufactured under parameters that allow high densification, and the obtained results will be correlated with their respective microstructures. The obtained samples will have their microstructure thoroughly characterized by X-ray Diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM), and chemical analysis by Energy Dispersive X-ray Spectroscopy (EDS). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RODRIGUES, L. C. M.; KOGA, G. Y.; FREITAS, B. J. M.; FIGUEIRA, G.; GARGARELLA, P.; BOLFARINI, C.; KIMINAMI, C. S.; BOTTA, W. J.. Wear-resistant Fe68Cr8Mo4Nb4B16 glass former coatings-From powder production by gas atomization to coating build-up by Laser Powder Bed Fusion. SURFACE & COATINGS TECHNOLOGY, v. 441, p. 12-pg., 2022-07-15. (13/05987-8, 19/05885-7, 19/01829-5, 17/27031-4, 21/08514-0)

RICCARDO AUGUSTO MOREIRA MONTUORI; GUSTAVO FIGUEIRA; THIAGO PACAGNAN CATALDI; NELSON GUEDES DE ALCÂNTARA; CLAUDEMIRO BOLFARINI; REGINALDO TEIXEIRA COELHO; PITER GARGARELLA. Manufatura Aditiva de Aço Inoxidável 316L por Fusão Seletiva a Laser. Soldagem & Inspeção, v. 25, 2020-09-28. (19/01829-5, 18/16898-0, 17/27031-4, 18/06691-9, 16/11309-0)