TY - GEN
T1 - The erosion-corrosion of intake valve sealing surfaces due to the formation of lubricating oil deposits
AU - Truhan, John J.
AU - More, Karren L.
AU - Rangarajan, Roger S.
PY - 2005
Y1 - 2005
N2 - Intake valves from natural gas-fired reciprocating engines displaying "torching" were examined to determine their failure mechanism. The principal features of the "torched" valves include a relatively thick black deposit on the tulip area of the valve extending to the sealing surface, partial loss of those deposits in various locations, and localized metal loss, oxidation and/or surface cracking in the spalled regions. Electron microprobe, scanning electron microscopy, and optical microscopy were employed to characterize the deposit formation and metal loss mechanisms. The initial cause of the torching appears to be due to the localized spallation of a loosely adherent (Ca,Zn) phosphate oil deposit adjacent to the valve/seat seal which creates a channel of hot, high velocity combustion gases. Within the torched area, significant metal oxidation and metal recession due to erosion/corrosion was observed on the valve sealing face, creating a relatively wide gap where a valve/seat seal should be. In areas where torching is not evident on the valve sealing surface, no appreciable metal recession (but limited metal oxidation) was observed.
AB - Intake valves from natural gas-fired reciprocating engines displaying "torching" were examined to determine their failure mechanism. The principal features of the "torched" valves include a relatively thick black deposit on the tulip area of the valve extending to the sealing surface, partial loss of those deposits in various locations, and localized metal loss, oxidation and/or surface cracking in the spalled regions. Electron microprobe, scanning electron microscopy, and optical microscopy were employed to characterize the deposit formation and metal loss mechanisms. The initial cause of the torching appears to be due to the localized spallation of a loosely adherent (Ca,Zn) phosphate oil deposit adjacent to the valve/seat seal which creates a channel of hot, high velocity combustion gases. Within the torched area, significant metal oxidation and metal recession due to erosion/corrosion was observed on the valve sealing face, creating a relatively wide gap where a valve/seat seal should be. In areas where torching is not evident on the valve sealing surface, no appreciable metal recession (but limited metal oxidation) was observed.
UR - http://www.scopus.com/inward/record.url?scp=33144465176&partnerID=8YFLogxK
U2 - 10.1115/wtc2005-64227
DO - 10.1115/wtc2005-64227
M3 - Conference contribution
AN - SCOPUS:33144465176
SN - 0791842029
SN - 9780791842027
T3 - Proceedings of the World Tribology Congress III - 2005
SP - 589
EP - 590
BT - Proceedings of the World Tribology Congress III - 2005
PB - American Society of Mechanical Engineers
T2 - 2005 World Tribology Congress III
Y2 - 12 September 2005 through 16 September 2005
ER -