| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pressure ring which can be used in environments in which there is a high thermal load of an engine having a high compression ratio, which has excellent heat conductivity and heat setting resistance, and which is cost-competitive, and to provide a method of manufacturing the same. <P>SOLUTION: Basically, a JIS registration material having a low alloy element content is used, and microstructure is adjusted to exhibit excellent heat setting resistance even at 300°C of high temperature. Concretely, a steel material having a material mark SUP10 as specified by JIS G 4801 is used. Prior to oil tempering, a piston ring wire material is subjected to annealing in order to disperse spheroidized cementite having an average grain size of 0.1-1.5 μm in a tempered martensite matrix. As a result, dislocation movement and creep are inhibited even at 300°C, and heat setting resistance is improved. <P>COPYRIGHT: (C)2012,JPO&INPIT |
