The depletion of ZDDP additives within marine lubricants and associated cylinder liner wear in RNLI lifeboat engines

Authors: Anand, M., Hadfield, M., Thomas, B. and Cantrill, R.

Journal: Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications

Volume: 231

Issue: 1-2

Pages: 162-170

eISSN: 2041-3076

ISSN: 1464-4207

DOI: 10.1177/1464420716663235

Abstract:

Previous work of authors indicated the wear of cylinder liners in marine engines of RNLI lifeboats due to the intense lubricant degradation identified by inductively coupled plasma and Fourier Transform Infrared spectroscopy techniques. In this paper, further analysis carried out to evaluate the effects of lubricant degradation on the actual cylinder liners installed in the Trent Class Lifeboat engines is presented. Surface characterisation of actual cylinder liner's bore surface showed maximum wear near the top dead centre region compared to rest of the piston stroke. Wear in this region of the cylinder liner surface is controlled primarily by the protective film forming anti-wear additives in the lubricant which limit the direct surface contact between the piston rings and cylinder liner. The condition of zinc dialkyldithiophosphates anti-wear additives was analysed using the nuclear magnetic resonance spectroscopy. Tribology analysis was conducted to evaluate the tribological and boundary film forming performance of zinc dialkyldithiophosphates additives by simulating cylinder liner-piston ring contact near the top dead centre. To further understand the wear mechanisms of the cylinder liner, wear debris analysis (Analytical Ferrography) of lubricant samples was performed. Results revealed the depletion of phosphorus containing zinc dialkyldithiophosphates anti-wear additives as a function of the lubricant's duty cycle within the marine engines and its effect on the tribological and boundary film forming performance of lubricants. Wear debris analysis showed the generation of ferrous debris potentially from the cylinder liners as a result of reduced anti-wear protection from the depleted zinc dialkyldithiophosphates additives during the tribological contact with piston rings and piston skirt region. These findings are useful to understand the lubricant degradation mechanisms which affect the functionality of cylinder liners, therefore allowing to plan the engine maintenance strategies.

Source: Scopus

The depletion of ZDDP additives within marine lubricants and associated cylinder liner wear in RNLI lifeboat engines

Authors: Anand, M., Hadfield, M., Thomas, B. and Cantrill, R.

Journal: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS

Volume: 231

Issue: 1-2

Pages: 162-170

eISSN: 2041-3076

ISSN: 1464-4207

DOI: 10.1177/1464420716663235

Source: Web of Science (Lite)

The depletion of ZDDP additives within marine lubricants and associated cylinder liner wear in RNLI lifeboat engines

Authors: Hadfield, M., anand, M., thomas, B. and Cantril, R.

Journal: Proc IMechE Part L:Journal of Materials: Design and Applications

Volume: 0

Issue: Special Issue MDA2016

Pages: 1-9

Publisher: Sage

DOI: 10.1177/1464420716663235

Abstract:

Previous work of authors indicated the wear of cylinder liners in marine engines of RNLI lifeboats due to the intense lubricant degradation identified by inductively coupled plasma and Fourier Transform Infrared spectroscopy techniques.

In this paper, further analysis carried out to evaluate the effects of lubricant degradation on the actual cylinder liners installed in the Trent Class Lifeboat engines is presented. Surface characterisation of actual cylinder liner’s bore surface showed maximum wear near the top dead centre region compared to rest of the piston stroke. Wear in this region of the cylinder liner surface is controlled primarily by the protective film forming anti-wear additives in the lubricant which limit the direct surface contact between the piston rings and cylinder liner. The condition of zinc dialkyldithiophosphates anti-wear additives was analysed using the nuclear magnetic resonance spectroscopy. Tribology analysis was conducted to evaluate the tribological and boundary film forming performance of zinc dialkyldithiophosphates additives by simulating cylinder liner–piston ring contact near the top dead centre. To further understand the wear mechanisms of the cylinder liner, wear debris analysis (Analytical Ferrography) of lubricant samples was performed. Results revealed the depletion of phosphorus containing zinc dialkyldithiophosphates anti-wear additives as a function of the lubricant’s duty cycle within the marine engines and its effect on the tribological and boundary film forming performance of lubricants. Wear debris analysis showed the generation of ferrous debris potentially from the cylinder liners as a result of reduced anti-wear protection from the depleted zinc dialkyldithiophosphates additives during the tribological contact with piston rings and piston skirt region. These findings are useful to understand the lubricant degradation mechanisms which affect the functionality of cylinder liners, therefore allowing to plan the engine maintenance strategies.

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Source: Manual