Title:
PRODUCTION OF MARTENSITIC STAINLESS STEEL SEAMLESS PIPE
Document Type and Number:
Japanese Patent JP3694967
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a producing method of a martensitic stainless steel seamless pipe excellent in the strength and the corrosion resistance without developing anisotropy by executing heat treatment in succession to a pipe-making in a pipe-making line.
SOLUTION: In the producing method of the stainless steel pipe by using the martensitic stainless steel, the following (1)-(3) processes are executed in order: (1) elongating work and finish work applied to a hollow base stock are executed at ≥40% the total working degree in both works and at 800-1,000°C finish temp. to make the seamless steel pipe; (2) the seamless steel pipe is charged into a supplemental heating furnace and the supplemental heating is executed at the temp. T (°C) for the time (t) (hr) so that the value of (fn) regulated with the formula, fn=(T+273)×(21+log t) and T≥800°C becomes a valve in the range of 22,000-27,000; and (3) the seamless steel pipe taken out from the supplemental heating furnace is cooled at ≥10°/min cooling velocity at least to 600°C and cooled to ≤200°C and successively, tempered at 500-780°C.
Inventors:
Kunio Kondo
Takeshi Ichinose
Takeshi Ichinose
Application Number:
JP9838096A
Publication Date:
September 14, 2005
Filing Date:
April 19, 1996
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21B3/02; B21B17/02; C21D8/10; C21D9/08; (IPC1-7): B21B3/02; B21B17/02; C21D8/10; C21D9/08
Domestic Patent References:
| JP1123029A | ||||
| JP7179943A | ||||
| JP1123024A | ||||
| JP63238217A |
Attorney, Agent or Firm:
Terutada Hogami
Michio Mori
Michio Mori
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