HEAT-RESISTANT STEEL AND GAS TURBINE MADE OF THE SAME.

摘要

This new heat-resistant steel has the following component compsn. (1) C (0.05-0.2 wt.%), Si (0.5 wt.% or less), Mn (0.6 wt.% or less), Cr (8-13 wt.%, Mo (1.5-3 wt.%), Ni (2-3 wt.%), V (0.05-0.3 wt.%), Nb and/or Ta (total amount : 0.02-2.0 wt.%), N (0.02-0.1 wt.%), Fe (the remaining wt.%), Mn/Ni is not more than 0.11 (2) C (0.07-0.15 wt.%), Si (0.01 or 0.1 wt.%), Mn (0.1-0.4 wt.%), Cr (11-12.5 wt.%), Ni (2.2-3.0 wt.%), Mo (1.8-2.5 wt.%), Nb and/or Ta (total amount:0.04 - 0.08 wt.%), Fe (the remaining wt.%), Mn/Ni = 0.04-0.10 (3) C (0.05-0.2 wt.%), Si (0.5 wt.% or less), Mn (0.6 wt.% or less), Cr (8-13 wt.%), Mo (1.5-3 wt.%), Ni (2-3 wt.%), V (0.05-0.3 wt.%), Nb and/or Ta (total amount : 0.02-0.2 wt.%), N (0.02-0.1 wt.%), W (1 wt.% or less), Co (0.5 wt.% or less), Cu (0.5 wt.% or less), B (0.01 wt.% or less), Ti (0.5 wt.% or less), Al (0.3 wt.% or less). Zr (0.1 wt.% or less), Hf (0.1 wt.% or less), Ca (0.01 wt.% or less), Mg (0.01 wt.% or less), Y (0.01 wt.% or less), rare earth elements (0.01 wt.% or less), Fe (the remaining wt.%). (1) has characteristics such as creep rupture strength of at least 50 kg/mm2 at 450 deg. C for 105 hours and a 25 V-notch Charpy impact value of at least 5 Kg/m/cm2 after heat treatment at 500 deg. C for 103 hours. Compsn. (2) has the annealed martensite structure. This heat-resistant steel is used for the turbine discs of a gas turbine which consists of a turbine shaft, a number of turbine discs, a number of compression discs connected to the distant pieces by compressor stacking bolts, compressor blades implated in the compressor discs and a compressor stub shaft shaped integrally at the initial stage of the compressor disc.