Hot-rolled tube billet heating process

Abstract

The invention relates to an annular furnace heating process for hot-rolled tube billet. The annular furnace comprises a furnace body and a rotary furnace bottom. The furnace body consists of six sections, i.e. a preheating section I, a preheating section II, a heating section I, a heating section II, a soaking section I and a soaking section II which are sequentially from a charging opening to a discharging opening. The inner side and the outer side of each section are respectively provided with a set of burners which are controlled by reversing valves. Sequential cyclic burning is carried out according to a determined reversing period and reversing interval. The tube billet is driven by the rotary furnace bottom to move from the charging opening to the discharging opening. The tube billet is discharged out of the furnace after sequentially undergoing preheating, heating and soaking. The head temperature of the hot tube billet coming out of the furnace is lower than the tail temperature thereof, and the temperature difference is controlled to be 30-60 DEG C. Through the reasonable setting of furnace temperature inside and outside the soaking sections and the control of the temperature difference between the head and the tail of the hot tube billet coming out of the furnace, the temperature of the head and the tail of a tubular billet for entering a continuous mill is uniform, thereby providing a better condition for the rolling of the continuous mill and effectively improving the quality and yield of the tubular billet.

Description

technical field

[0001] The invention belongs to the technical field of hot rolling production of oil well pipes, and relates to a heating treatment process for hot rolling production of oil well pipes, in particular to an annular furnace heating process for hot rolling pipe blanks. Background technique

[0002] At present, the basic process of producing hot-rolled capillaries on the continuous rolling production lines of hot-rolled and restrained mandrels at home and abroad is: tube billet heating - piercing - continuous rolling with continuous rolling mills. The discharge temperature of the tube blank is mainly based on the needs of the continuous rolling mill. If the temperature of the capillary tube entering the continuous rolling mill is too low, the phenomenon of holding the mandrel will occur after continuous rolling, which will make it difficult to remove the rod, and the thin-walled continuous rolling tube will also be pulled. Therefore, it is hoped that the capillar...