| 摘要 |
<p>PURPOSE:To execute a bright annealing of a stainless bar steel under excellent workability by arranging an atmospheric gas continuous zone between a heating zone and a cooling zone at the time of annealing after heating and rapidly cooling the long austenitic stainless bar steel. CONSTITUTION:The long bar steel W made of the austenitic stainless steel is passed through a high frequency induction heating machine 1 composed of a refractory-made cylindrical part 10 provided with a coil-state induction heating device 11 forming a water-cooling type copper tube in the inner part. The high frequency current is conducted in the induction heating device 11 and the stainless steel-made bar steel W is heated with the induction current and successively, rapidly cooled in the cooling zone 8 of a cooling liquid vessel and annealed. In this case, the atmospheric gas continuous zone 7 is arranged between the heating zone 6 and the cooling zone 8, and an ammonia decomposition gas or the other inert gas, etc., is supplied from the inlet 3. The stainless steel-made bar steel W heated to the austenitic single phase temp. is supplied into the cooling vessel without oxidizing the surface, and the long bar steel material made of the austenitic stainless steel is stably bright-annealed.</p> |
