HEAT TREATMENT OF LONG-SIZED PIPE MATERIAL

PURPOSE:To reduce the consumption of a nonoxidizing atmospheric gas and to improve the quality by a heat treatment by subjecting a long-sized pipe installed in a furnace to the prescribed heat treatment while supplying the nonoxidizing atmospheric gas into the pipe from one end thereof. CONSTITUTION:The long-sized pipe material W wound on a spool 44 is imposed on a stage 46 and a connecting part 50 is connected to the pipe material W. An inner case 31 and an outer case 32 are put on the stage 46. One end W1 of the pipe material W is opened and the connecting pipe 50 is connected via a connector 51 to an atmosheric gas supply pipe 36. The inside of the pipe material W is purged while the nonoxidizing atmospheric gas such as nitrogen is passed into the pipe material W and is released from the other end W1. While the flow rate of the gas is regulated, the entire part of the pie material W is heated by a heater attached to the outer case 32, and the pipe material is subjected to the prescribed holding treatment. The air does not exist in the pie material W according to the above-mentioned method and therefore, the quality of the product is improved.