Abstract: A highly corrosion resistant high strength stainless steel pipe for linepipe, having a composition containing about 0.001 to about 0.015% C, about 0.01 to about 0.5% Si, about 0.1 to about 1.8% Mn, about 0.03% or less P, about 0.005% or less S, about 15 to about 18% Cr, about 0.5% or more and less than about 5.5% Ni, about 0.5 to about 3.5% Mo, about 0.02 to about 0.2% V, about 0.001 to about 0.015% N, and about 0.006% or less O, by mass, so as to satisfy (Cr+0.65 Ni +0.6Mo+0.55Cu?20C?18.5), (Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9 N?11.5) and (C+N?0.025). Preferably quenching and tempering treatment is applied to the pipe. The composition may further contain about 0.002 to about 0.05% Al, and may further contain one or more of Nb, Ti, Zr, B, and W, and/or Cu and Ca. The microstructure preferably contains martensite, ferrite, and residual ?.

Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu?20C?18.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less.

Abstract: A stainless steel pipe for use in oil wells which has a high strength having a YS of 654 MPa or more and superior corrosion resistance even in a severe corrosive environment in which CO2 and are present and the temperature is high, such as up to 230° C. The pipe contains on a mass percent basis: 0.005% to 0.05% of C; 0.05% to 0.5% of Si; 0.2% to 1.8% of Mn; 0.03% or less of P; 0.005% or less of S; 15.5% to 18% of Cr; 1.5% to 5% of Ni; 1% to 3.5% of Mo; 0.02% to 0.2% of V; 0.01% to 0.15% of N; 0.006% or less of 0; and the balance being Fe and unavoidable impurities, in which Cr+0.65Ni+0.6Mo+0.55Cu?20C?19.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11.5 are satisfied (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent the respective contents on a mass percent basis).

Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu?20C?18.5 and Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less. The composition may further contain at least one element of Nb and Ti; at least one element selected from the group consisting of Zr, B, and W; or Ca, singly or in combination.

Abstract: A highly corrosion resistant high strength stainless steel pipe for linepipe, having a composition containing about 0.001 to about 0.015% C, about 0.01 to about 0.5% Si, about 0.1 to about 1.8% Mn, about 0.03% or less P, about 0.005% or less S, about 15 to about 18% Cr, about 0.5% or more and less than about 5.5% Ni, about 0.5 to about 3.5% Mo, about 0.02 to about 0.2% V, about 0.001 to about 0.015% N, and about 0.006% or less O, by mass, so as to satisfy (Cr+0.65Ni+0.6Mo+0.55Cu?20C?18.5), Cr+Mo+0.3Si?43.5C?0.4Mn?Ni?0.3Cu?9N?11.5) and (C+N?0.025). Preferably quenching and tempering treatment is applied to the pipe. The composition may further contain about 0.002 to about 0.05% Al, and may further contain one or more of Nb, Ti, Zr, B, and W, and/or Cu and Ca. The microstructure preferably contains martensite, ferrite, and residual ?.

Abstract: A stainless steel pipe for use in oil wells is proposed which has a high strength having a YS of 654 MPa or more and superior corrosion resistance even in a severe corrosive environment in which CO2 and Cl? are present and the temperature is high, such as up to 230° C. The pipe contains on a mass percent basis: 0.005% to 0.05% of C; 0.05% to 0.5% of Si; 0.2% to 1.8% of Mn; 0.03% or less of P; 0.005% or less of S; 15.5% to 18% of Cr; 1.5% to 5% of Ni; 1% to 3.5% of Mo; 0.02% to 0.2% of V; 0.01% to 0.15% of N; 0.006% or less of O; and the balance being Fe and unavoidable impurities, in which Cr+0.65Ni+0.6Mo+0.55Cu?20C?19.5 and Cr+Mo+0.3Si?43.5C?0.4Mn—Ni?0.3Cu?9N?11.5 are satisfied (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent the respective contents on a mass percent basis).

Abstract: A steel composition contains: 0.05% or less of C; 0.5% or less of Si; 0.20% to 1.80% of Mn; 0.03% or less of P; 0.005% or less of S; 14.0% to 18.0% of Cr; 5.0% to 8.0% of Ni; 1.5% to 3.5% of Mo; 0.5% to 3.5% of Cu; 0.05% or less of Al; 0.20% or less of V; 0.01% to 0.15% of N; and 0.006% or less of O on a mass basis, and satisfies the following expressions: Cr+0.65Ni+0.6Mo+0.55Cu−20C≧18.5 and Cr+Mo+0.3Si−43.5C−0.4Mn−Ni−0.3Cu−9N≦11 (where Cr, Ni, Mo, Cu, C, Si, Mn, and N represent their respective contents (mass %)). After such a steel pipe material is formed into a steel pipe, the steel pipe is quenched by cooling after heating to a temperature of the AC3 transformation point or more and tempered at a temperature of the AC1 transformation point or less. The composition may further contain at least one element of Nb and Ti; at least one element selected from the group consisting of Zr, B, and W; or Ca, singly or in combination.

Abstract: A process and an equipment for micro-pattern forming on the surface of a rolling roll, and a metallic thin sheet and preparation thereof by transferring a micro-pattern on the surface by use of the roll are provided. Such a rolling roll can be attained by a method wherein resin film mixed with optical absorbing agent is formed on the surface, a Q switch YAG laser having an output of 5 to 100W is applied to make a marking on this resin film, a part of the coated film is removed in strict accordance with the pattern, then an etching process is applied to the roll surface. The metallic thin sheet skin pass rolled by this roll is used as a car panel and is superior in pressworkability and sharpness of reflections.