Sumitomo Metal Industries, Inc.

Nippon Steel Sumitomo Metal Corporation

Hiroki Kusuda

Yasuyoshi Hidaka

Sumio Iida

Mutsumi Tanida

Kouji Nakaike

Yasuhisa Kasa

Masami Sakiyama

Hisao Yamasaki

Tadayoshi Fujisaka

A seamless tube is manufactured while effectively suppressing the occurrence of carburization in the seamless tube without interfering with operations. A seamless tube is manufactured by a step of washing at least a portion of a conveyor installed in a conveying step of a mandrel bar B which is situated from a lubricant applying deviceto the entrance of a mandrel mill, a step of washing, on the upstream side of the lubricant applying device, a mandrel bar B which was used for elongation rolling, and a step of applying a non-graphite-based lubricant to the mandrel bar B with the lubricant applying device, wherein the conveyor and the mandrel bar B are each washed such that the amount of graphite C2 (g/m) adhering to the surface of the mandrel bar B before it is provided to elongation rolling and the amount of carbon C1 (g/m) contained in the organic binder of the applied lubricant satisfy Equation 1: 0.08&#xd7;C1+0.05&#xd7;C2&#x2266;3 and Equation 2: 3&#x2266;C1+C2&#x2266;50.

Manufacturing method and cleaning equipment for seamless tube

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Osaka, Japan

Hiroki Kusuda