Patent ID: 8663549

Claim:
A heat-resisting steel for engine valves excellent in high temperature strength, comprising: in % by mass, C: 0.20 to 0.50%, Si: 1.0% or less, Mn: 5.0% or less, P: 0.1 to 0.5%, Ni: 8.0 to 15.0%, Cr: 16.0 to 25.0%, Cu: 0.03 to 0.5%, Nb: 0.03% or more and 1.0% or less, W: 2.0% or less (including 0%), Mo: 0.03% or more and less than 2.0%, N: 0.02 to 0.30%, B: 0.01% or less, and remnants of Fe and impurities, the heat-resisting steel for engine valves satisfying Formulae below: 156.42P(%)+0.91Mo(%)+0.73W(%)−12.27Nb(%)+220.96 N(%)+120.59≧170 Formula (1) 13.70P(%)−6.97Mo(%)−4.32W(%)−3.29Nb(%)+119.10N(%)+27.75≧30 Formula (2).