Rail manufacturing method and manufacturing equipment

A rail-manufacturing equipment that performs forced cooling on at least a head of a rail that is hot after hot-rolled at an austenite region temperature or higher or after heated to the austenite region temperature or higher, the rail-manufacturing equipment comprising:

• a first cooling device including a first head-cooling header configured to jet a cooling medium toward the head of the rail and a first head thermometer configured to measure surface temperature of the head of the rail;
• a second cooling device including a second head-cooling header configured to jet the cooling medium toward the head of the rail and a second head thermometer configured to measure surface temperature of the head of the rail;
• and
• a controller configured to adjust jet of the cooling medium from the first head-cooling header and the second head-cooling header, wherein
• the controller includes a temperature-monitoring unit configured to monitor measurement results by the first head thermometer and the second head thermometer during the forced cooling, and
• the controller further includes a cooling-rate controller configured to:
• adjust the jet of the cooling medium from the first head-cooling header for 10 seconds from start of the forced cooling so that a cooling rate at a surface of the head becomes 1° C./s to 20° C./s;
• determine beginning and end of heat generation during transformation based on a history of the measurement results by the first head thermometer monitored by the temperature-monitoring unit, and adjust the jet of the cooling medium from the first head-cooling header during a period from the beginning to the end of the heat generation during transformation so that the cooling rate at the surface of the head becomes lower than 1° C./s or a temperature-rising rate becomes 5° C./s or lower;
• adjust the jet of the cooling medium from the first head-cooling header during a period after the end of the heat generation during transformation until temperature inside the head of the rail becomes 550° C. to 650° C. so that the cooling rate at the surface of the head becomes 1° C./s to 20° C./s;
• instruct the rail to be conveyed to the second cooling device after the temperature inside the head of the rail becomes 550° C. to 650° C.;
• and
• adjust the jet of the cooling medium from the second cooling header during a period until temperature at the surface of the head of the rail becomes 450° C. or lower toward the rail forcedly cooled in the first cooling device so that the cooling rate at the surface of the head of the rail becomes 2° C./s to 20° C./s.