Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Mitsubishi Hitachi Power Systems, Ltd.

Shunichi Otsuka

Yoshitaka Nishiyama

Takeshi Miki

Atsuro Iseda

Hiroshi Matsuo

Kazuhiro Uchida

Takashi Nakashima

Kiyoko Takeda

Takuya Hanada

Masami Sakiyama

Tsutomu Shima

Provided is an alloy having a high strength and a low thermal expansion coefficient. The alloy according to the present disclosure includes a chemical composition containing, in mass %: C: 0.10% or less, Si: 0.50% or less, Mn: 0.15 to 0.60%, P: 0.015% or less, 5: 0.0030% or less, Ni: 30.0 to 40.0%, Cr: 0.50% or less, Mo: 0.50% or less, Co: 0.250% or less, Al: 0.0150% or less, Ca: 0.0050% or less, Mg: 0.0300% or less, N: 0.0100% or less, O: 0.0300% or less, Pb: 0.0040% or less, and Zn: 0.020% or less, one or more elements selected from the group consisting of Nb: 0 to less than 0.145%, Ti: 0 to less than 0.145%, and. V: 0 to less than 0.145%: 0.015 to less than 0.145% in total, with the balance being Fe and impurities, and satisfying Formula (1).(Nb+3×Ti+V)/(C+N)≤6.00  (1)

Alloy

The production method for producing a rifled tube, which includes a plurality of first helical ribs on its inner surface, includes: a steps of: preparing a steel tube; and producing a rifled tube by performing cold drawing on a steel tube by using a plug which includes a plurality of second helical ribs, the plug satisfying Formulae and:0.08 &#x3c;&#xd7;()&#xd7;/(2&#x3c0;&#xd7;)&#x3c;0.26&#x2003;&#x2003;(1)0.83&#x3c;&#xd7;()&#xd7;/(2&#xd7;)&#x3c;2.0&#x2003;&#x2003;(2)where, W is a width of a groove bottom surface of the helical groove; A is a maximum diameter of the plug; B is a minimum diameter of the plug; N is a number of the second helical ribs; S is the width of the groove bottom surface; and M is a pitch of adjacent second helical ribs.

Method for producing a rifled tube

There is provided a heat resistant ferritic steel including a base material including, by mass percent, C: 0.01 to 0.3%, Si: 0.01 to 2%, Mn: 0.01 to 2%, P: at most 0.10%, 5: at most 0.03%, Cr: 7.5 to 14.0%, sol.Al: at most 0.3%, and N: 0.005 to 0.15%, the balance being Fe and impurities, and an oxide film that is formed on the base material and contains 25 to 97% of Fe and 3 to 75% of Cr. This heat resistant ferritic steel is excellent in photoselective absorptivity and oxidation resistance.

Heat resistant ferritic steel and method for producing the same

A method of producing a metal pipe which can suppress quenching defects is provided. In the method, a bend of the metal pipe is straightened by a straightening machine. Next, both pipe end portions of the metal pipe whose bend has been straightened are cut off by a pipe cutting apparatus. Next, a plurality of the metal pipes whose both pipe end portions have been cut off are aligned in the axial direction thereof to be conveyed to a quenching apparatus, and the metal pipes are quenched by being cooled after being heated by induction heating.

Production method and production facility of metal pipe

There is provided a heat resistant ferritic steel including a base material including, by mass percent, C: 0.01 to 0.3%, Si: 0.01 to 2%, Mn: 0.01 to 2%, P: at most 0.10%, S: at most 0.03%, Cr: 7.5 to 14.0%, sol.Al: at most 0.3%, and N: 0.005 to 0.15%, the balance being Fe and impurities, and an oxide film that is formed on the base material and contains 25 to 97% of Fe and 3 to 75% of Cr. This heat resistant ferritic steel is excellent in photoselective absorptivity and oxidation resistance.

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Tokyo, Japan

Shunichi Otsuka