Welded titanium pipe and welded titanium pipe manufacturing method

Patent metadata

Field	Value
Publication number	US-2017074599-A1
Application number	US-201515122457-A
Country	US
Kind code	A1
Filing date	Mar 11, 2015
Priority date	Mar 18, 2014
Publication date	Mar 16, 2017
Grant date	—

Abstract

Provided are a welded titanium tube capable of improving heat-transfer performance and detecting surface defects and a manufacturing method therefor. The welded titanium tube is formed of a tubular-shaped titanium plate, whose edges are butt-welded. The welded titanium tube includes an outer peripheral surface and an inner peripheral surface, at least one of which is provided with a concavo-convex pattern including a base surface and a plurality of protrusions. A mean maximum height of the protrusions is in the range of 12 to 45 μm. A ratio of a maximum value to a mean pitch of the protrusions is less than 2. A ratio of a mean maximum dimension of the protrusions to the mean pitch is 0.90 or less, and a ratio of the mean maximum height to a wall thickness is 0.11 or less.

First claim

1 . A welded titanium tube formed of a titanium plate in a tubular shape, opposite edges of the plate being butt-welded, comprising an outer peripheral surface and an inner peripheral surface, at least one of the outer peripheral surface and the inner peripheral surface being provided with a concavo-convex pattern including a base surface and a plurality of protrusions each protruding beyond the base surface in a radial direction of the welded titanium tube, wherein:
the plurality of protrusions are spaced in at least one of an axial direction and a circumferential direction of the welded titanium tube; a mean value Ha of respective maximum heights of the protrusions is set so as to satisfy the following relationship: 12 μm≦Ha≦45 μm; a ratio of a maximum value Pmax of a pitch of the protrusions in a specific arrangement direction to a mean value Pa of the pitch of the protrusions is set so as to satisfy the following relationship: Pmax/Pa<2, the specific arrangement direction being one direction of the axial and circumferential directions of the welded titanium tube, the one direction being a direction in which the plurality of protrusions are spaced at a smaller pitch than a pitch at which the plurality of protrusions are spaced in the other direction of the axial and circumferential directions of the welded titanium tube; a ratio of a mean value da of respective maximum dimensions of the protrusions in the specific arrangement direction to the mean value Pa of the pitch is set so as to satisfy the following relationship: da/Pa≦0.90; and a ratio of the mean value Ha of the respective maximum heights of the protrusions to a wall thickness t of the welded titanium tube at a lowest spot of the base surface is set so as to satisfy the following relationship: Ha/t≦0.11.

2 . A method for manufacturing the welded titanium tube as recited in claim 1 , comprising:
a concavo-convex pattern provision step of providing a concavo-convex pattern to at least one of a front surface and a back surface of a titanium plate having a longitudinal direction and a width direction orthogonal to the longitudinal direction, so as to space the plurality of protrusions in at least one of the longitudinal and width directions; a formation step of forming the titanium plate into a tubular shape by applying a curvature along the width direction to the titanium plate provided with the concavo-convex pattern to butt opposite edges thereof in the width direction against each other; and a welding step of joining the widthwise opposite and mutually butted edges of the titanium plate to each other by welding.

Assignees

• Kobe Steel Ltd

Inventors

• Tamura Keitaro
• Fujii Yasuyuki
• Itsumi Yoshio
• Oyama Hideto

Classifications

• B21D53/06

  of metal tubes · CPC title

• B23K9/23

  taking account of the properties of the materials to be welded · CPC title

• F28F1/124 Primary

  and being formed of pins · CPC title

• B23K2101/06

  Tubes · CPC title

• B21C37/08 Primary

  Making tubes with welded or soldered seams {(with helically arranged seams B21C37/122)} · CPC title