Influences of High-Temperature Short-Time Endurance Performance of Heat Resistant Steel for Ultra Supercritical Units

Abstract:

Heat-resistant steel (12%wt. Cr) used in the ultra supercritical set blade was quenched and tempered by vacuum heat treatment furnace, the mechanical properties and metallographic structures at room temperature can meet the specific requirements. However, there are some problems existed on high-temperature short-time lasting performance. To improve the high temperature endurance performance of materials, the experimental testing and analysis were carried out fro different types of specimen. The research showed that short-time rupture is a kind of creep fracture, and short lasting strength was closely related to test temperatures between laths and grain boundary and carbide coarsening. Energy spectrum analysis revealed that cast in the hole had high B element content (19.98%wt.), which meant grain boundaries of the B at high temperature began to migrate and form in the crystal B in that second phase particles are contained, and grain boundary strength was obviously decreased. The enduring high temperature experiment indicated that the strength were declined rapidly and fractured suddenly at high temperature.

• Periodical: Materials Science Forum (Volume 749)
• Pages: 361-365
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.749.361
• Online since: March 2013
• Authors: Hua Tang, Feng Xiao, Jian Sheng Ding, Zhi Hong Li
• Keywords: Carbides Coarsening, Crack, Heat-Resistant Steel, Short-Time Endurance Performance

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