PROCESS FOR MANUFACTURE OF SEAMLESS STEEL PIPE

Title:

PROCESS FOR MANUFACTURE OF SEAMLESS STEEL PIPE

Document Type and Number:

WIPO Patent Application WO/2012/086177

Kind Code:

A1

Abstract:

In the piercing rolling using a plug having a protective coating film formed on the surface thereof, a lubricant agent that is an aqueous solution containing one or more of boron oxide, boric acid and a boron amine salt in the total amount of 5-30 mass% is applied onto the protective coating film on the surface of the plug and the resulting plug is used for the piercing rolling, whereby it becomes possible to improve the service life of the piercing rolling plug reliably without deteriorating the efficiency of the piercing rolling and, consequently, it becomes possible to manufacture a seamless steel pipe with high efficiency. It is preferred that the plug is cooled after the piercing rolling, the lubricant agent is applied while keeping the temperature of the surface of a tip of the plug at 100˚C or lower, and the resulting plug is used again for the piercing rolling. In the constitution, it is preferred that the protective coating film on the surface of the plug is formed by the arc spraying of an iron wire material onto the surface of the matrix of the plug and is composed of an oxide and Fe.

Inventors:

TATEBAYASHI YOSUKE (JP)
HIGASHIDA YASUTO (JP)
IIDA SUMIO (JP)

Application Number:

PCT/JP2011/007092

Publication Date:

June 28, 2012

Filing Date:

December 20, 2011

Export Citation:

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Assignee:

SUMITOMO METAL IND (JP)
TATEBAYASHI YOSUKE (JP)
HIGASHIDA YASUTO (JP)
IIDA SUMIO (JP)

International Classes:

B21B19/04; B21B25/04

Foreign References:

JP2001234189A	2001-08-28
JPH08117819A	1996-05-14
JP4279350B1	2009-06-17

Other References: