Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Naoki Sawawatari

Masaki Ueyama

Koichi Kuroda

Kouichi Kuroda

Hitoshi Suwabe

Nao Otaki

Takahiro Izawa

Yusuke Ugawa

Norifumi Kochi

To provide an austenitic stainless steel material having a high creep strength and a high creep ductility even in a high-temperature environment at 800&#xb0; C. or more. An austenitic stainless steel material according to the present disclosure has a chemical composition that includes, in mass %: C: 0.060% or less; Si: 1.0% or less; Mn: 2.00% or less; P: 0.0010 to 0.0400%; S: 0.010% or less; Cr: 10 to 25%; Ni: 25 to 45%; Nb: 0.2 to 2.0%; W: 2.5 to 6.0%; B: 0.0010 to 0.0100%: Al: 2.5 to 4.5%; and the balance being Fe and impurities, and satisfies Formulae (1) and (2), and the sum of the content of dissolved Nb and the content of dissolved W is 3.2 mass % or more.(W/184+Nb/93)/(C/12)&#x2265;5.5&#x2003;&#x2003;(1)(W/184+Nb/93)/(B/11)&#x2264;450&#x2003;&#x2003;(2) In Formulae (1) and (2), the content in mass % of the corresponding element is substituted for each symbol of element.

Austenitic stainless steel material

A dual phase stainless steel pipe includes tensile yield strength YSof 689.1 MPa to 1000.5 MPa in a pipe axis direction of the dual phase stainless steel pipe, in which the tensile yield strength YS, a compressive yield strength YSin the pipe axis direction, a tensile yield strength YSin a pipe circumferential direction of the dual phase stainless steel pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy all Expressions (1) to (4),0.90&#x2264;YS/YS&#x2264;1.11&#x2003;&#x2003;(1)0.90&#x2264;YS/YS&#x2264;1.11&#x2003;&#x2003;(2)0.90&#x2264;YS/YS&#x2264;1.11&#x2003;&#x2003;(3)0.90&#x2264;YS/YS&#x2264;1.11&#x2003;&#x2003;(4).

Dual phase stainless steel pipe and manufacturing method thereof

There is provided an austenitic alloy pipe that is durable even if a stress distribution different according to usage environment is applied. The austenitic alloy pipe in accordance with the present invention has a tensile yield strength YSof at least 689.1 MPa. The tensile yield strength YS, a compressive yield strength YSin a pipe axial direction, a tensile yield strength YSin a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy Formulas (1) to (4).0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(1)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(2)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(3)0.90&#x2266;&#x2266;1.11&#x2003;&#x2003;(4)

Austenitic alloy pipe and method for producing the same

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Tokyo, Japan

Naoki Sawawatari