Microstructure and creep behaviour of P92 steel after HPT

The microstructure and creep behaviour of the welded joints of P92 steel pipe were investigated in order to determine the influence of orbital heat welding technology on the creep resistance. Creep specimens were machined from the welded joints. Tensile creep tests of welded joints were performed at 873 K using different stresses. The microstructure of tested specimens was investigated by scanning electron microscope Tescan equipped with an electron-back scatter diffraction. The creep results showed that the creep fracture strain of the welded joints decreases with decreasing value of applied stress. Microstructure investigation showed that fracture behaviour of welded joints is influenced by an enhanced cavity formation at grain boundaries in the heat-affected zone causing lower fracture ductility.

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Characterization of the cyclic softening and remaining creep behaviour of P92 steel weldment

Journal of Materials Research and Technology ◽

10.1016/j.jmrt.2021.09.013 ◽

2021 ◽

Vol 15 ◽

pp. 1446-1456

Author(s):

Wei Zhang ◽

Xiaowei Wang ◽

Zitong Kang ◽

Tianyu Zhang ◽

Yong Jiang ◽

...

Keyword(s):

Creep Behaviour ◽

Cyclic Softening ◽

P92 Steel ◽

Steel Weldment

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Creep Damage and Fracture in Advanced Tungsten Modified 9%Cr Ferritic Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.713.183 ◽

2016 ◽

Vol 713 ◽

pp. 183-186 ◽

Cited By ~ 1

Author(s):

Vàclav Sklenička ◽

K. Kuchařová ◽

M. Kvapilová ◽

Petr Král ◽

Jiří Dvořák

Keyword(s):

Creep Strength ◽

Ferritic Steel ◽

Nuclear Power ◽

Power Plants ◽

Creep Behaviour ◽

Creep Damage ◽

Creep Tests ◽

P92 Steel ◽

Damage And Fracture ◽

Isothermal Ageing

Advanced tungsten modified 9%Cr ferritic steel (ASTM Grade P92) is a promising material for the next generation of fossil and nuclear power plants. Unfortunately, there are rather few published reports on damage processes in P92 steel during high temperature creep and the effect of damage evolution on the creep strength is not fully understood. In this work, the creep behaviour of P92 steel in as-received condition and after long-term isothermal ageing was investigated at 600 and 650°C using uniaxial tension creep tests. To quantify the effect of each damage process on the loss of creep strength, most of creep tests were followed by microstructural and fractographic investigations. It was found that the large Laves phase particles, which coarsened during creep exposure, served as preferential sites for creep cavity nucleation.

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