METHOD FOR CORRECTING PIPE AND METHOD FOR PRODUCING PIPE BY USING THAT CORRECTION METHOD

Title:

METHOD FOR CORRECTING PIPE AND METHOD FOR PRODUCING PIPE BY USING THAT CORRECTION METHOD

Document Type and Number:

WIPO Patent Application WO/2007/119817

Kind Code:

A1

Abstract:

When a pipe is corrected by using a roll correction machine provided with drum type correction rolls arranged oppositely in the vertical direction, at least the outer layer portions of at least three pairs of correction rolls on the output side of the correction machine is formed of an elastic body having spring type hardness Hs (JIS K6301 A type) of 50-100. An offset amount formed at three positions corresponding to the axis of pipe at the intersections of vertical correction rolls in the above correction rolls, and providing η, defined by expression (1), of 1.0X10-3-1.5X10-3 is imparted to the pipe. Consequently, S/N ratio is enhanced in eddy current flaw detection from the inner surface of pipe, inspection efficiency can be enhanced, and excellent quality precision can be ensured in a heat exchanger tube for use in a steam generator, or the like. (1) where, a relation, R=(δ2+L2)/2δ is satisfied assuming the outside diameter of the tube is d (mm), the stand distance of roll correction machine is L (mm), and the offset amount is δ (mm).

Inventors:

TSUYUGUCHI SATOSHI (JP)
KURODA KOUICHI (JP)
YAMAKAWA TOMIO (JP)

Application Number:

PCT/JP2007/058157

Publication Date:

October 25, 2007

Filing Date:

April 13, 2007

Export Citation:

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Assignee:

SUMITOMO METAL IND (JP)
TSUYUGUCHI SATOSHI (JP)
KURODA KOUICHI (JP)
YAMAKAWA TOMIO (JP)

International Classes:

B21D3/04; B21D3/02

Foreign References:

JP2000317521A	2000-11-21
JPS61286025A	1986-12-16
JPS55103222A	1980-08-07

Other References: