The Structures and High Temperature Properties of High Chromium-Nickel Heat-Abrasion Resistant Steels Containing Nitrogen, Rare -Earth and Niobium

摘要

The structures and high temperature properties of high chromium-nickel heat-abrasion resistant steels containing nitrogen, rare-earth and niobium were studied. The test results showed that:(1)After quenching and age-hardening the microstructure of the steel was composed of austenite+M_(23) C_6 +σ-phase; (2)High temperature endurance strength σ_(1000) at 1000°C was 16.8MPawhich was higher than that of traditional heat-resistant steels as 40Cr25Ni20steel etc.; (3)The oxidation resistance at 1000°C was similar to 40Cr25Ni20steel and higher than that of traditional heat-resistant steels as35Crl8Ni25Si2 steel etc.; (4)The Vicker's hardness at 1000°C was HV 38.Thecoal powder spraying nozzles of boilers at power stations work under a condition of combined severe abrasion-erosion and oxidation at an elevated temperature of 800-1200°C.The service life of the nozzles made of the steel developed in the present paper was 3.5 times as high as that of30Cr22Ni4Mn7Si2RE steel.