| 摘要 |
<p>A metal ring of generally rectangular cross-section has its radially outer surface and its side surfaces treated by being stacked with its sides in contact with other rings in a chamber. Air is excluded from the chamber and a gaseous mixture of a carburizing gas and a nitrogenous gas at a temperature of 450 DEG C. to 650 DEG C. is supplied to the chamber. The proportions (% by volume) of the gases is between 25:75 and 75:25. The mixture nitro-carburizes both the radially outer surface of the stacked rings and the sides of the ring. If the rings are finish machined before treatment, they are ready for use as soon as they are removed from the chamber. The nitro-carburizing treatment reduces wear on the treated surfaces. The rings are used as piston rings or sealing rings.</p> |
