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Study of stainless steels modified by additions of boron and nitrogen in order to obtain wear resistant materials with low friction coefficient

Grant number: 14/27073-0
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): December 01, 2015
Effective date (End): February 06, 2017
Field of knowledge:Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
Principal Investigator:Claudemiro Bolfarini
Grantee:Juliano Soyama
Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
Associated research grant:13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys, AP.TEM

Abstract

The oil industry is technologically and economically very important and it has gained a continuously growing interest in Brazil. From the components and materials point of view, there are many challenges on this demanding field, especially considering the severe wear and corrosion environments found offshore. A critical case corresponds to the pipelines used for oil exploitation and drilling, also known as risers. Normally hot rolled stainless steels that show suitable corrosion resistance are used for this type of application. However, depending on the circumstances, their tribological properties might be rather poor. Recently, Prof. Bolfarini, DEMa/UFSCar in a joint effort with Petrobras coordinated a project for the development of modified wear resistant stainless steels prepared by spray forming. Boron additions were conducted in order to precipitate hard boride particles, which were responsible for the improved wear resistance. As a natural follow up for this successful project, another very important tribological property, the friction coefficient, will be investigated in this study. In this context, a metallurgical solution for the simultaneous improvement of wear resistance and to achieve a low friction coefficient was elaborated by adding or precipitating hard and lubricant particles. Among the high performance lubricant materials, hexagonal boron nitride shows outstanding properties due to its structure that is very similar to graphite. Consequently, this proposal is focused on the study of stainless steels modified with nitrogen and boron, prepared via spray forming to obtain in situ precipitation of iron/chromium borides and hexagonal boron nitride. The starting point will be a super duplex stainless steel with 0.3%N (wt.%) and progressive additions of boron according to calculations/simulations to be performed with Thermocalc software. The resistance to corrosion and wear will be evaluated and the results compared with the materials developed to date by the research group, as well as with commercially available materials. (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)
SOYAMA, JULIANO; LOPES, THIAGO PAMA; ZEPON, GUILHERME; KIMINAMI, CLAUDIO SHYINTI; BOTTA, WALTER JOSE; BOLFARINI, CLAUDEMIRO. Wear Resistant Duplex Stainless Steels Produced by Spray Forming. METALS AND MATERIALS INTERNATIONAL, v. 25, n. 2, p. 456-464, MAR 2019. Web of Science Citations: 3.
LOPES, THIAGO PAMA; SOYAMA, JULIANO; ZEPON, GUILHERME; COSTA NASCIMENTO, ALEXANDRE ROMAO; COSTA E SILVA, ANDRE; KIMINAMI, CLAUDIO SHYINTI; BOTTA, WALTER JOSE; BOLFARINI, CLAUDEMIRO. Thermodynamic Calculations for the Investigation of Phase Formation in Boron-Modified Ferritic Stainless Steel. JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION, v. 38, n. 3, p. 343-349, JUN 2017. Web of Science Citations: 3.
SOYAMA, JULIANO; ZEPON, GUILHERME; LOPES, THIAGO PAMA; BERALDO, LEAMAR; KIMINAMI, CLAUDIO SHYINTI; BOTTA, WALTER JOSE; BOLFARINI, CLAUDEMIRO. Microstructure formation and abrasive wear resistance of a boron-modified superduplex stainless steel produced by spray forming. Journal of Materials Research, v. 31, n. 19, p. 2987-2993, OCT 2016. Web of Science Citations: 5.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.