Abstract: A Ni—Cr—Mo—Nb alloy consists of, in mass %, C: not more than 0.020%, Si: 0.02 to 1.0%, Mn: 0.02 to 1.0%, P: not more than 0.03%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 8.0 to 10.0%, Al: 0.005 to 0.4%, Ti: 0.1 to 1.0%, Fe: not more than 5.0%, Nb: 2.5 to 5.0%, N: 0.002 to 0.02%, and at least one of W: 0.02 to 0.3% and V: 0.02 to 0.3%, and Ni as a remainder and inevitable impurities, in which an freely selected cross section of alloy, sum of number of particles of NbC carbide and (Ti, Nb)N nitride is 100 to 1000 particles/mm2, number of particles of the NbC carbide is not more than 40 particles/mm2, and number of particles of the (Ti, Nb)N nitride is 100 to 1000 particles/mm2.

Abstract: A precipitation hardening martensitic stainless steel consists of in mass %, C: 0.01 to 0.07%, Si: 1.0 to 2.5%, Mn: 0.1 to 2.5%, P: not more than 0.04%, S: not more than 0.0020%, Ni: 4.0 to 10.0%, Cr: 11.0 to 17.0%, Mo: 0.1 to 1.50%, Cu: 0.30 to 6.0%, Al: 0.001 to 0.200%, N: 0.001 to 0.020%, Ti: 0.15 to 0.45%, Nb: 0.15 to 0.55%, and Fe and inevitable impurities as a remainder, and satisfies the following formula (1): Ti + 30 × N ? 0.9 .

Abstract: [Summary] [Assignment] A precipitation hardening martensitic stainless steel having superior strength and improved welding properties. [Solution] In mass %, C: 0.030 to 0.065%, Si: 1.0 to 2.0%, Mn: 0.51 to 1.50%, P: not more than 0.04%, S: not more than 0.0020%, Ni: 4.0 to 10.0%, Cr: 11.0 to 18.0%, Mo: 0.1 to 1.50%, Cu: 0.30 to 6.0%, Al: 0.005 to 0.2%, Sn: 0.003 to 0.030%, N: 0.001 to 0.015%, Ti: 0.15 to 0.45%, Nb: 0.15 to 0.55%, Ca: not more than 0.0025%, Mg: 0.0001 to 0.0150%, O: not more than 0.01% and Fe and inevitable impurities as a remainder, and satisfying the following formula (1). and ?cal. (vol. %) defined by the formula (2) is in a range of 1.0 to 9.0. Sn+0.009Cu?0.06??(1) ?cal. (vol. %)=4.3(1.3Si+Cr+Mo+2.2Al+Ti+Nb)?3.9(30C+30N+Ni+0.8Mn+0.3Cu)?31.

Abstract: A Ni—Cr—Mo alloy having superior workability and corrosion resistance of a welded part, the alloy consists of in mass %, C: 0.002 to 0.020%, Si: 0.02 to 1.00%, Mn: 0.02 to 1.00%, P: not more than 0.030%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 7.5 to 9.0%, Cu: 0.01 to 0.20%, Al: 0.005 to 0.400%, Ti: 0.1 to 1.0%, Fe: 3.0 to 6.0%, Nb: 2.5 to 4.0%, Co: 0.01 to 0.50%, V: 0.05 to 0.50%, N: 0.002 to 0.020%, Sn: 0.003 to 0.030%, W: 0.05 to 0.50%, Nb+Ti+V: 2.5 to 4.5%, Cu+10Sn: not more than 0.40, and Ni and inevitable impurities as a remainder.

Abstract: A Ni—Cr—Mo—Nb alloy consists of, in mass %, C: not more than 0.020%, Si: 0.02 to 1.0%, Mn: 0.02 to 1.0%, P: not more than 0.03%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 8.0 to 10.0%, Al: 0.005 to 0.4%, Ti: 0.1 to 1.0%, Fe: not more than 5.0%, Nb: 2.5 to 5.0%, N: 0.002 to 0.02%, and at least one of W: 0.02 to 0.3% and V: 0.02 to 0.3%, and Ni as a remainder and inevitable impurities, in which an freely selected cross section of alloy, sum of number of particles of NbC carbide and (Ti, Nb)N nitride is 100 to 1000 particles/mm2, number of particles of the NbC carbide is not more than 40 particles/mm2, and number of particles of the (Ti, Nb)N nitride is 100 to 1000 particles/mm2.

Abstract: A swage fastening structure includes a first plate member including a plate main body and a T-shaped swaging piece, and a second plate members including a fastening hole through which the swaging piece passes. The swaging piece includes: a shaft portion; and a pair of holding pieces configured such that an end surface of each holding piece close to the plate main body is inclined in a direction of gradually getting away from the plate main body from one end close to the shaft portion to the other end thereof, and is formed such that a dimension between the plate main body and the one end close to the shaft portion is smaller than a plate thickness of the second plate member and a dimension between the plate main body and the other end is larger than the plate thickness of the second plate member.

Abstract: A thin plate burring processing method includes a first step of forming a thin portion thinner than an original thickness in a target portion by performing crushing processing on the target portion of a plate-like workpiece, a second step of forming a circular through-hole in the thin portion by punching processing, and a third step of forming an annular portion rising from a surface of the workpiece by performing projection processing with burring processing around the through-hole formed in the thin portion.

Abstract: A method of manufacturing a pipe body having a rectangular cross section, including preparing a metal plate having edges parallel to each other and bending lines parallel to the edges, forming malleable portions extending perpendicular to the bending lines, forming the metal plate into an intermediate product by bending at the bending lines such that the intermediate product includes a center bottom wall, adjoining walls, and two upper walls, applying external forces to the adjoining walls so as to expand and curve the center bottom wall outward, thereby bringing the edges in the upper walls into intimate contact, and applying external force to the curved center bottom wall so as to flatten the center bottom wall and maintain the edges in close contacted condition with a spring back force in the center bottom wall, wherein the malleable portions are formed in the adjoining walls.

Abstract: A method of manufacturing a pipe body having a rectangular cross section, including preparing a metal plate having edges parallel to each other and bending lines parallel to the edges, forming malleable portions extending perpendicular to the bending lines, forming the metal plate into an intermediate product by bending at the bending lines such that the intermediate product includes a center bottom wall, adjoining walls, and two upper walls, applying external forces to the adjoining walls so as to expand and curve the center bottom wall outward, thereby bringing the edges in the upper walls into intimate contact, and applying external force to the curved center bottom wall so as to flatten the center bottom wall and maintain the edges in close contacted condition with a spring back force in the center bottom wall, wherein the malleable portions are formed in the adjoining walls.