Sumitomo Electric Industries, Limited

Sumitomo Rubber Industries Limited

Nippon Steel Corporation

Sumitomo Electric Tochigi Co., Ltd.

Tetsuya Nakajima

Hiromu Izumida

Shinei Takamura

Koji Fujisawa

Masumi Suzuki

Kenichi Yamashita

Takashi Tokuyama

Junichi Kodama

Katsutoshi Iwamoto

Kazuaki Sugimura

Ken Manabe

Akifumi Matsuoka

Fuminori Okada

Hiroyuki Fujioka

A steel wire having a cross section perpendicular to a longitudinal direction having a flat shape, and an outer shape of the cross section including a pair of linear parts opposing each other, and a pair of curved parts opposing each other and connecting the linear parts. The curved part includes a pair of first regions located at positions near the linear parts, and a second region located at a position between the pair of first regions, a radius of curvature, Rof the first region is greater than or equal to 0.05 mm but less than 0.15 mm, and a radius of curvature, Rof the second region is greater than or equal to 0.13 mm but less than or equal to 0.2 mm, and an angle between the linear part and the curved part is greater than or equal to 165 degrees.

Steel wire and tire

A steel wire is formed of a steel containing: not less than 0.6 mass % and not more than 0.7 mass % carbon, not less than 1.2 mass % and not more than 2.1 mass % silicon, not less than 0.2 mass % and not more than 0.6 mass % manganese, not less than 1.4 mass % and not more than 2 mass % chromium, and not less than 0.15 mass % and not more than 0.3 mass % vanadium, with the balance being iron and unavoidable impurities. The steel includes a matrix made up of tempered martensite, and a non-metallic inclusion present in the matrix. When √area of the non-metallic inclusion is represented as Hand √area of a region including both the non-metallic inclusion and a decreased-hardness portion is represented as H, a ratio of Hto H, or, H/His at least 1 and less than 1.3.

Steel wire and spring

A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities. A value obtained by dividing a sum of a Si content and a Mn content by a Cr content is not less than 0.9 and not more than 1.4. The steel constituting the main body has a tempered martensite structure.

Spring steel wire

There is provided a steel cord including a steel wire and a plating layer that covers the steel wire and has Cu, Zn, and Co, wherein Cu and Zn are alloyed and a region covered with Co and a region not covered with Co are mixed on the outermost surface of the plating layer.

Steel cord and method for producing the same

A tire having a rubber body in which a steel cord is embedded, wherein a layer composed of ZnCoO is formed at the interface between the steel cord and the rubber body and x+y is 5/6 or more and 1 or less.

Tire

Growing community of inventors

Utsunomiya, Japan

Tetsuya Nakajima