Rohr aus Rostfreiem Stahl und Ölbohrlochrohr

Details

Veröffentlichungs-Nr.

EP4782564

Anmeldetag

17. Januar 2025

Veröffentlichung

11. September 2025

Rechtsraum

EP

Abstract

An object of the present invention is to provide a stainless steel pipe having high strength and excellent hydrogen embrittlement resistance. The expression "having excellent hydrogen embrittlement resistance" means that, in a tensile test under hydrogen charging, the elongation after fracture is 9.0% or more, and that, in the tensile test, when the horizontal axis represents the true strain, the vertical axis represents the true stress, and a true strain at a maximum load is denoted by ε<max>, a rate of change d<2>σ/dε<2> of a work hardening rate dσ/dε with respect to ε is -200,000 MPa or more in a true strain range of 0.8ε<max> or more and ε<max> or less. σ denotes the true stress (MPa), and ε denotes the true strain (no units). The term "high strength" refers to a yield strength of 450 MPa or more. The stainless steel pipe has a specific microstructure, in which an average KAM value which is an average of a KAM (Kernel Average Misorientation) value of the steel microstructure is 2.0° or more and 4.0° or less, and a standard deviation of a distribution of the KAM value is 1.5° or less.

Anmelder

Firma

JFE Steel Corporation

Land

🇯🇵 Japan