1. Failure analysis of a titanium Coriolis mass flow meter: A case of hydrogen embrittlement
- Author
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Danielle Cristina Camilo Magalhães, G.S. Vacchi, I.G.R. Santos, Cristie Luis Kugelmeier, Carlos Alberto Della Rovere, R. Silva, and G.R. Campesan
- Subjects
Materials science ,Hydrogen ,Mass flow meter ,Hydride ,Metallurgy ,General Engineering ,Titanium alloy ,chemistry.chemical_element ,020101 civil engineering ,02 engineering and technology ,Flow measurement ,0201 civil engineering ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,General Materials Science ,Embrittlement ,Hydrogen embrittlement ,Titanium - Abstract
Titanium alloys are suitable for construction of the Coriolis mass flow meter due to their high strength to weight ratio, high thermal stability and excellent corrosion resistance. However, environments with high hydrogen content can be very harmful to titanium and its alloys, since this element may cause hydride formation and leads to hydrogen embrittlement. In this context, this paper reports on the analysis of a grade 9 titanium tube of a mass flow meter, which was performed using cyclohexanol (68%), water (2%) and Raney nickel catalyst (30%). After the active period, the flow meter was deactivated and left on standby for one year, and then reassembled on a production line, whereupon it failed prematurely. The failure was analyzed by OM, SEM, EDS, Vickers microhardness and XRD, whose results indicated that the cause was hydride embrittlement due to the chemical interaction between Raney nickel and the titanium tube during the deactivated period.
- Published
- 2020
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