Influence of heatingcooling cycles on long-term strength of cast heat-resistant alloy 45Cr26Ni33Si2Nb2

Experimentally was determined long-term strength at the temperature of 1150 °C of heat-resistant alloy 45Cr26Ni33Si2Nb2 in two conditions: cast and after preliminary exposure at 1150 °C in the range of time 2–100 hours with the subsequent cooling in the furnace. It was detected that catathermal working conditions influence on long-term strength of the alloy more negative by comparison with isothermal, especially in an initial stage of operation. It was recommended to reduce quantity of technological heating-cooling cycles for an increase of the remaining life of the high-temperature equipment made from heat-resisting Fe-Cr-Ni-alloys.