Abstract: The high-strength steel for steel forgings according to the present invention has a composition that includes, as basic components, C: 0.35 mass % to 0.47 mass %; Si: 0 mass % to 0.4 mass %; Mn: 0.6 mass % to 1.5 mass %; Ni: more than 0 mass % up to 2.0 mass %; Cr: 0.8 mass % to 2.5 mass %; Mo: 0.10 mass % to 0.7 mass %; V: 0.035 mass % to 0.20 mass %; Al: 0.015 mass % to 0.050 mass %; N: 30 ppm to 100 ppm, and O: more than 0 ppm up to 30 ppm, the balance being Fe and inevitable impurities. The metal structure is mainly bainite, martensite or a mixed structure of bainite and martensite. Among cubic B1-type precipitates, the number of coherent precipitates having a diameter equal to or smaller than 30 nm is equal to or smaller than 50/?m2.

Abstract: The high-strength steel for steel forgings according to the present invention has a composition that includes, as basic components, C: 0.35 mass % to 0.47 mass %; Si: 0 mass % to 0.4 mass %; Mn: 0.6 mass % to 1.5 mass %; Ni: more than 0 mass % up to 2.0 mass %; Cr: 0.8 mass % to 2.5 mass %; Mo: 0.10 mass % to 0.7 mass %; V: 0.035 mass % to 0.20 mass %; Al: 0.015 mass % to 0.050 mass %; N: 30 ppm to 100 ppm, and O: more than 0 ppm up to 30 ppm, the balance being Fe and inevitable impurities. The metal structure is mainly bainite, martensite or a mixed structure of bainite and martensite. Among cubic B1-type precipitates, the number of coherent precipitates having a diameter equal to or smaller than 30 nm is equal to or smaller than 50/?m2.

Abstract: A nonaqueous ink composition for an ink jet recording, comprising (A) a urethane resin dispersant with an acidic functional group, (B) a pigment, and (C) an organic solvent [and optionally (D) a thermal reactive compound], characterized in that the urethane resin dispersant (A) is a branched urethane resin dispersant prepared by polymerizing a terminal-isocyanate-containing compound (p), which has been prepared by reacting (a) a polyisocyanate having three or more isocyanate groups, and (b) a monoalcohol, under the condition that a molar ratio (Ma/Mb) of the number of moles (Ma) of isocyanate groups (NCO) from the polyisocyanate (a) to the number of moles (Mb) of hydroxyl groups (OH) from the monoalcohol (b) is 3/2 to 3/0.