| 摘要 |
PURPOSE:To obtain the corrosion resistant double pipe having no rupture caused on the way of the expansion of an inner pipe nor variation in the thickness by respectively specifying the material of an outer pipe and inner pipe, inserting the inner pipe into the outer pipe and expanding the inner pipe with its pressurization by heating it at a specific temp. CONSTITUTION:A carbon steel, low alloy steel or an austenite stainless steel is selected as the material for an outer pipe 1 and on the other hand the outer pipe 1, inner pipe 2 are respectively prepared by selecting the Ti, Zr and these alloy steels excellent in a corrosion resistance and having smaller thermal expansion coefft. than that of the material of the outer pipe 1 as the material for the inner pipe 2. A clad pipe is then made by inserting the inner pipe 2 into the outer pipe 1, heated at 350-800 deg.C, the inner pipe 2 is expanded with its pressurization simultaneously and a corrosion resistant double pipe is obtd. by compactly fixing the inner pipe 2 and outer pipe 1 by cooling them thereafter.
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