Dai-Ichi High Frequency Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Kenji Saita

Takeshi Yamamoto

Kenji Sugiyama

Nobuhiko Matsumoto

Ryuta Harada

Masaharu Ueda

Hiroshi Fukuchi

Kenichi Karimine

Yasunobu Tsutsumi

A post-heating treatment device includes a detecting device for a height variation of a surface of the rail at every, predetermined pitch along a length direction of the rail, a control unit for defining a position of the rail to be a starting point of the welded section when the height variation detected by the detecting device at every predetermined pitch exceeds a predetermined threshold for the number of a predetermined times consecutively and defining a position of the rail to be an end point of the welded section when the height variation detected by the detecting device at every predetermined pitch is below the predetermined threshold for the number of the predetermined times consecutively, and a heating unit for heat treatment based on a position of the welded section detected by the detecting device. A post-heating treatment method using the post-heating treatment device is provided.

Post-heating treatment device and post-heating treatment method

A post-heating treatment device performs a post-heating treatment for a welded section of a rail, after an induction heating coil is automatically disposed at a predetermined position based on the welded section. The device includes welded section detecting unit for detecting the position of a welded section on a rail, a first coil and a second coil that form an induction heating coil, first coil moving unit for moving the first coil to a position spaced apart from the rail at a predetermined distance, second coil moving unit for moving the second coil to a position separated from the rail at a predetermined distance, where the second coil is contacted to the first coil, clamping unit for pressing against the contact portion between the first coil and the second coil, and current applying unit for applying a predetermined current to the formed induction heating coil.

This welding method is a flash butt welding method of a pair of track rail steel pieces, having: a preheating process in which electric current is made to flow for a predetermined time in a state in which the welding surfaces of a pair of track rail steel pieces are forcibly brought into contact with each other, and vicinities of the welding surfaces are heated by resistance heating; a former flashing process in which flashing is partially caused in the welding surfaces, and the welding surfaces are heated by the resistance heating and arc heating of the flashing; and a latter flashing process in which the flashing is furthermore caused throughout the entire welding surfaces, and the entire welding surfaces are uniformly heated by the resistance heating and arc heating of the flashing, in which a latter flashing velocity is 2.1 mm/sec to 2.8 mm/sec in the latter flashing process.

Flash butt welding method of rail steel

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Tokyo, Japan

Kenji Saita