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Indexed by:会议论文

Date of Publication:2009-01-01

Included Journals:CPCI-S

Page Number:343-346

Key Words:HR3C; High-temperature mechanical properties; High temperature short time tensile test; Aging

Abstract:HR3C (25Cr-20Ni-Nb-N) is a new austenitic steel used as superheat and reheater tubes in Ultra-supercritical Boiler. The purpose of this paper is to research the steel's high-temperature mechanical properties and the effects of precipitates after thermal aging by the high temperature short time tensile. The experimental materials were supply state specimens and thermal aging specimens. The experiment temperatures were 650 degrees C and 750 degrees C. The results showed that the yield strengths of thermal aging HR3C Were superior to the supply state specimens. The optical microstructure of thermal aging specimen showed that there were numerous precipitates along the intergranulars and in the intracrystallines. It indicated that these precipitations increased yield strength of the thermal aging specimen. There was an interesting result obtained from the stress-strain curves only considering the temperature influence. The supply state specimen has preferable plasticity at the lower temperature. This abnormal phenomenon was resulted in precipitates along the grain boundaries when this state specimen was tested at higher temperature.