| 摘要 |
PURPOSE: To provide a postheat treatment method which improves the progress of hardening in heat affected zones in areas in vicinity of a travelling plane without necessitating the troublesome use of a cooling medium and is highly economically executed at the work site for laying railways with an equipment cost kept as low as possible. CONSTITUTION: The traveling plane in weld zones and the heat affected zones adjacent thereto is impactively heated by means of a torch 11 from above over a time period of 50 to 150 seconds after the weld zones are cooled. At this time, each time the travelling plane is heated, the torch 11 is loaded with oxygen of at least 10,000 l/h and propane or acetylene of at least 3,500 l/h and the combustion face of a torch heat is positioned at a distance of a value (unit of measurement: mm) corresponding to 0.1 to 1.0 times the figure by weight meter (unit of measurement: kg) of a rail 13 to be used from the travelling plane in the weld zones and the heat affected zones. |
