Method for producing thermally tandem-rolled seamless steel pipes

Abstract

The invention discloses a method for producing thermally tandem-rolled seamless steel pipes. The method comprises the following steps that: a buffering attemperator stores continuous cast round steel provided by a steelmaking continuous casting workshop in a heat preservation state in a way of buffering and provides the continuous cast round steel for a stepping soaking pit furnace; the stepping soaking pit furnace soaks and heats the continuous cast round steel provided by the buffering attemperator; a hot saw cutting device performs hot saw cutting on the continuous cast round steel provided by the stepping soaking pit furnace to obtain fixed-size tube blanks; and a heat preservation cover preserves or raises the temperature of the fixed-size tube blanks provided by the hot saw cutting device and conveys the fixed-size tube blanks into a perforator to perforate the fixed-size tube blanks at the temperature needed by the perforator. By the invention, the process of 'hot loading and hot conveying' is realized. Compared with the traditional production process, the method can save over 40 percent of energy and reduce over 1 percent of burning loss.

Description

technical field [0001] The invention relates to the technical field of steel pipe production technology, in particular to a production method for hot continuous rolling seamless steel pipes. Background technique [0002] The traditional seamless steel pipe production method is as follows: after the steelmaking and continuous casting workshop provides the cold continuous casting round tube billet with a length of 6-9m, the continuous casting tube is cut by cold sawing (or other cold cutting methods) in the hot rolling tube workshop. The round tube billet is cut into a length of about 1.5-4.5m to length; it is cut into a round tube billet in a range of 1.5-4.5m under heating and cooling in a traditional ring furnace, and is sent to perforation after being heated to 1150-1280°C . The traditional method for producing seamless steel pipes in which the continuous casting round billet is cooled first and then heated again wastes energy greatly. [0003] In the hot rolling system ...

AI Technical Summary

Problems solved by technology

In order to meet the requirements of a rolling rhythm of 15s and 240 main tubes per hour, the loading and unloading machine must adopt the method of loading (or discharging) two tube blanks at the same time, which has certain difficulties in design and actual production;

[0006] (2) In the field of seamless steel pipe production, the annual output of a single set is more than 500,000 tons / year or the annual output of multiple sets of units is more than 500,000 tons / year, and the required continuous casting round tube billet is 2-2 The four types of specifications are the initial conditions that match the steelmaking and continuous casting workshops, but most of the factories that have been built and put into production do not meet this condition;

[0007] (3) The steelmaking and continuous casting workshop and the hot-rolled pipe workshop of the factory that has been built and put into production are set up separately. After the intermediate transportation between the two workshops, the continuous casting round tube billet cannot guarantee a higher furnace charging temperature (the Temperature is a sensitive value that reflects the energy-saving effect), which is also a restrictive condition for adopting the "hot charging and hot delivery" process;

[0008] (4) If the "hot charging and hot delivery" production method is adopted, the ratio of hot charging and hot delivery (the percentage of the output produced by the hot charging and hot delivery method to the total output) should be more than 40%, otherwise the comprehensive economic benefits will be very poor

However, due to the large number of product varieties and steel types, it is difficult for the manufacturers that have been built and put into production to achieve the above-mentioned ratio of hot charging and hot delivery

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