HIGH Cr CAST IRON HAVING EXCELLENT FATIGUE FAILURE RESISTANCE, AND METHOD FOR PRODUCING THE SAME

摘要

PPROBLEM TO BE SOLVED: To provide high Cr cast iron having excellent fatigue failure resistance in which brittle fracture caused by fatigue crack propagation can be prevented even in high hardness and in a using environment where the generation of repeated tensile stress is generated, and to provide a method for producing the same. PSOLUTION: The high Cr cast iron having excellent fatigue failure resistance has a specified high Cr cast iron composition, and has a structure where the size of martensite is refined, and further, retained austenite is comprised by a fixed amount. The structure is obtained by solidification cooling velocity upon specified casting, quenching holding temperature, quenching holding time, and quenching cooling velocity. The high Cr cast iron has a high hardness of 800 Hv, a high toughness of 2.0 J/cmSP2/SPby Charpy impact value, and whose threshold of stress intensity factor range Kth where fatigue crack propagation does not occur is 10. PCOPYRIGHT: (C)2007,JPO&INPIT