Alloy pipe and method for producing same
AssigneeJfe Steel Corporation
InventorsShunsuke Sasaki, Masao Yuga, Tatsuro Katsumura, Hideo Kijima
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Abstract
An alloy pipe and a method for producing the same are disclosed. The alloy pipe of the present invention contains, as a component composition, in terms of % by mass, Cr: 11.5-35.0%, Ni: 23.0-60.0%, and Mo: 0.5-17.0%, has an austenitic phase as a microstructure, has a Mo concentration (% by mass) in a grain boundary of the austenitic phase that is 4.0 times or less than a Mo concentration (% by mass) within grains of the austenitic phase, and has a tensile yield strength in a pipe axial direction of 689 MPa or more and a ratio (compressive yield strength in a pipe axial direction)/(tensile yield strength in a pipe axial direction) of 0.85 to 1.15.
Claims16
An alloy pipe
- comprising, as a component composition, in terms of % by mass,
- Cr:
- 11.5-35.0%,
- Ni:
- 23.0-60.0%, and
- Mo:
- 0.5-17.0%,
- the alloy pipe being a steel alloy pipe having an austenitic phase as a microstructure,
- having a Mo concentration (% by mass) in a grain boundary of the austenitic phase that is 4.0 times or less than a Mo concentration (% by mass) within grains of the austenitic phase, and
- having a tensile yield strength in a pipe axial direction of 689 MPa or more and a ratio (compressive yield strength in a pipe axial direction)/(tensile yield strength in a pipe axial direction) of 0.85 to 1.15.
Dependencies are inferred from the claim text.