Nippon Steel Corporation

Kazuo Sugino

Hideaki Kageyama

Hiroaki Sakamoto

Toru Inaguma

Hiroki Masumoto

Masaharu Ueda

Eiichi Takeuchi

Hiroyuki Tanaka

Kaname Wada

Kou Miyamura

Kenzo Ando

Kazuo Kanamaru

Rail axial-force measuring method and an axial-force measurable rail

Stress sensor fabricated from a material having precipitated granular

A process for manufacturing high-strength bainitic steel rails with an excellent rolling-contact fatigue resistance comprising the steps of hot rolling steel containing 0.15% to 0.45% carbon, 0.15% to 2.00% silicon, 0.30% to 2.00% manganese, 0.50% to 3.00% chromium, and at least one element selected from a group of molybdenum, nickel, copper, niobium, vanadium, titanium and boron, subjecting the hot-rolled rail to an accelerated cooling from the austenite region to a temperature between 500.degree. to 300.degree. C., at which the accelerated cooling is stopped, at a rate of 1.degree. to 10.degree. C. per second, and then further cooling the rail to a lower temperature by natural or controlled cooling. The obtained rail exhibits a hardness of Hv 300 to 400 in the center of the rail head surface of the head and not lower than Hv 350 in the gage corner, and the hardness of the gage corner is higher than that of the center of the rail head surface by Hv 30 or more.

Process for manufacturing high-strength bainitic steel rails with

A method of producing a composite metal material such as clad bloom by continuous casting comprises the steps of supplying molten metals of different compositions by using two immersion nozzles into the strand pool at different positions and forming a static magnetic field zone on the boundary between the two types of metals to prevent mixing of the metals of different composition. The method enables production of a composite material exhibiting a sharp boundary between the two types of metals used and enables the thickness of the respective metal layers to be easily controlled by adjusting the location of application of the static magnetic field or the withdrawal speed of the strand of cast metal.

Continuous casting process for composite metal material

A method for manufacturing high strength rail having excellent weldability comprises subjecting a steel rail of specific composition to specific heat treatment conditions at the surface layer portion of the head thereof, to impart high strength to the rail and to assure that the welded portion as well as the welded heat affected zone are free from deterioration caused by the welding process. The heat treatment conditions include a cooling rate which is substantially equivalent to that in a conventional welding process so as to impart high tensile strength to the treated portion of the rail.

Method for manufacturing high strength rail of excellent weldability

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Fukuoka, Japan

Kazuo Sugino