Austenitic alloy pipe and method for producing the same
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsNaoki Sawawatari, Kouichi Kuroda, Hitoshi Suwabe, Masaki Ueyama
Life of this patent
Estimating the term…
Abstract
There is provided an austenitic alloy pipe that is durable even if a stress distribution different according to usage environment is applied. The austenitic alloy pipe in accordance with the present invention has a tensile yield strength YSLT of at least 689.1 MPa. The tensile yield strength YSLT, a compressive yield strength YSLC in a pipe axial direction, a tensile yield strength YSCT in a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSCC in the pipe circumferential direction satisfy Formulas (1) to (4). 0.90≦YSLC/YSLT≦1.11 (1) 0.90≦YSCC/YSCT≦1.11 (2) 0.90≦YSCC/YSLT≦1.11 (3) 0.90≦YSCT/YSLT≦1.11 (4)
Claims19
An austenitic alloy pipe, wherein
- a tensile yield strength YSLT in a pipe axial direction of the alloy pipe is at least 689.1 MPa;
- and
- the tensile yield strength YSLT, a compressive yield strength YSLC in the pipe axial direction, a tensile yield strength YSCT in a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSCC in the pipe circumferential direction satisfy Formulas (1) to (4).
- 0.90≦YSLC/YSLT≦1.11 (1)
- 0.90≦YSCC/YSCT≦1.11 (2)
- 0.90≦YSCC/YSLT≦1.11 (3)
- 0.90≦YSCT/YSLT≦1.11 (4)
A method for producing an austenitic alloy pipe, comprising:
- a process for producing an austenitic alloy material pipe;
- a process for cold-working the material pipe;
- and
- a process for producing an austenitic alloy pipe, wherein by subjecting the cold-worked material pipe to straightening and low-temperature heat treatment at 300 to 550° C., the alloy pipe is provided with a tensile yield strength YSLT of at least 689.1 MPa in a pipe axial direction of the alloy pipe, and wherein for the alloy pipe, the tensile yield strength YSLT, a compressive yield strength YSLC (MPa) in the pipe axial direction, a tensile yield strength YSCT (MPa) in a pipe circumferential direction, and a compressive yield strength YSCC (MPa) in the pipe circumferential direction satisfy Formulas (1) to (4).
- 0.90≦YSLC/YSLT≦1.11 (1)
- 0.90≦YSCC/YSCT≦1.11 (2)
- 0.90≦YSCC/YSLT≦1.11 (3)
- 0.90≦YSCT/YSLT≦1.11 (4)
Dependencies are inferred from the claim text.