| 摘要 |
<p>Metal rings of rectangular cross-section are carbonitrided by placing a stack of the rings in a chamber, from which air is evacuated and which is filled with a gaseous mixt. of a carbon-contg. gas and a nitrogen-contg. gas in a volume ratio of 25-75:75-25 (pref. ammonia gas and an exothermic hydrocarbon gas in vol. ratio 50:50 or 60:40), and heating at 450-650 deg.C to carbonitride the radial outer surfaces and the sides of the rings. - The method is useful for carbonitriding steel or cast iron piston rings for engines or compressors and sealing rings for shock absorbers. The process gives additional hardening of the side faces of the rings so that the rings have better wear resistance, improved sealing properties and improved working life compared with conventional chromium coated rings. Additionally, the radially outer faces have higher wear resistance, wear resistance and wettability by lubricating oils than chromium-coated rings. DEAB- DE3245689 C Metal rings of rectangular cross-section are carbonitrided by placing a stack of the rings in a chamber, from which air is evacuated and which is filled with a gaseous mixt. of a carbon-contg. gas and a nitrogen-contg. gas in a volume ratio of 25-75:75-25 (pref. ammonia gas and an exothermic hydrocarbon gas in vol. ratio 50:50 or 60:40), and heating at 450-650 deg.C to carbonitride the radial outer surfaces and the sides of the rings. - The method is useful for carbonitriding steel or cast iron piston rings for engines or compressors and sealing rings for shock absorbers. The process gives additional hardening of the side faces of the rings so that the rings have better wear resistance, improved sealing properties and improved working life compared with conventional chromium coated rings. Additionally, the radially outer faces have higher wear resistance, wear resistance and wettability by lubricating oils than chromium-coated rings. (18pp) - DE3245689 C Metal rings of rectangular cross section, used as piston or sealing rings, are nitrocarburised in a stack of rings, which is charged into a chamber, that is evacuated and then filled with a gaseous mixture of a C-contg. gas and a N-contg. gas in a ratio of 25:75 to 75:25, pref. 50:50 or 80:40 (vol.%). The process of nitrocarbursing the radial outer surfaces and sides of the rings at 450-650 deg.C. Pref. the N-contg. gas is ammonia gas and an exotheric hydrocarbon gas is used as C-contg. gas. The rings, of cast iron or steel, are finish machined</p> |
