| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat-resisting steel for exhaust valves, which contains a relatively small amount of Ni and has excellent mechanical characteristics (such as tensile strength, fatigue strength, wear resistance and hardness) at high temperatures and excellent corrosion resistance. <P>SOLUTION: The heat-resisting steel for exhaust valves contains 0.45 mass% or more but less than 0.60 mass% C, 0.30-0.50 mass% (exclusive) N, 19.0 mass% or more but less than 23.0 mass% Cr, 5.0 mass% or more but less than 9.0 mass% Ni, 8.5 mass% or more but less than 10.0 mass% Mn, 2.5 mass% or more but less than 4.0 mass% Mo, 0.01 mass% or more but less than 0.50 mass% Si and 0.01 mass% or more but less than 0.30 mass% Nb, with the balance made up of Fe and unavoidable impurities. This heat-resisting steel for exhaust valves satisfies 0.02≤Nb/C<0.70 and 4.5≤Mo/C<8.9. <P>COPYRIGHT: (C)2013,JPO&INPIT |
