Patent ID: 6213474
Filing Date: 2001-04-10
Classification: C23C,F16J

Abstract:
A combination of compression rings, including a first compression ring and a second compression ring, for use in internal combustion engines, said first compression ring being made of steel material containing C of not less than 0.16 and not more than 1.4 weight percent, and Cr of not less than 12 and not more than 23.0 weight percent, said steel material of said first compression ring having mainly chromium carbide precipitated in the base texture thereof, said steel material of said first compression ring then having a hardened layer of hardness of not less than Hv1050 formed thereon by means of surface treatment, said second compression ring being made of steel material containing C of not less than 0.4 and not more than 0.8 weight percent, Si of not less than 0.16 and not more than 0.4 weight percent, Mn of not less than 0.1 and not more than 0.4 weight percent, and Cr of not less than 2.0 and not more than 11.0 weight percent, said steel material of said second compression ring having mainly chromium carbide precipitated in the base texture thereof, said steel material of said second compression ring then having a hardened layer of hardness of less than Hv1050 formed thereon by means of surface treatment.