A production process of a seamless steel pipe used for rolling an integral finned pipe

Abstract

A production process of a seamless steel pipe used for rolling an integral finned pipe is disclosed. The process includes sawing a raw material pipe blank off by adopting a sawing machine, subjecting the pipe blank to cold centering treatment through an automatic centering machine, heating the pipe blank in a continuous heating furnace, setting the heating temperature according to heating requirements, allowing the pipe blank temperature to be uniform through detecting the heating temperature in real time and through automatic closed-loop furnace temperature control, selecting and regulating tools and molds according to a rolling table in a punching rolling process, reasonably arranging the number of cold-drawing passes according to process requirements, arranging annealing steps among the passes, drawing a liner core in a finished-product pass, and performing stress relief annealing in a continuous roller hearth furnace after a steel pipe having a finished product dimension is obtained through drawing. Through adopting the production process, the rolled integral finned pipe is improved in quality and precision, and stable in organization performance. Safety performance of a manufactured heat exchanger is further improved, thus eliminating hidden dangers of leakage and explosion, and prolonging the service lifetime of the heat exchanger.

Description

technical field [0001] The invention relates to a production process of a raw material (base) tube of a finned tube, in particular to a production process of a seamless steel tube for rolling integral finned tubes. Background technique [0002] Integral finned tubes are more advanced and are the most widely used heat exchange tube elements - various finned tubes such as serial fins, wound and wound welded fins, in terms of anti-corrosion, wear resistance ( Anti-wear), low contact resistance (lower contact resistance), high stability (Higher Stability) and anti-dusting ability, etc., have significant advantages. [0003] In the existing rolling production line of integral finned tubes, common cold-drawn thick-walled seamless steel tubes are used. Keep the following questions: 1. Dimensional tolerance [0004] Ordinary cold-drawn thick-walled seamless steel pipes that meet the current national standards, due to large dimensional tolerances, especially large deviations in the...

AI Technical Summary

Problems solved by technology

Keep the following questions: 1. Dimensional tolerance

[0005] 1) The straightness of finned tubes after rolling (currently there is no national standard) is poor and irreversible, which affects the accuracy of installation and production of heat exchangers;

[0006] 2) The circumferential difference in heat transfer performance of finned tubes is increased, which affects the consistency of heat transfer efficiency;

[0007] 3) The pressure bearing capacity of the finned tube is determined by the minimum wall thickness (S) of the base tube. If the size deviation is large, the pressure bearing capacity will be reduced, and the safety factor will be reduced. accident, resulting in huge losses

[0008] 2. Process defects and organizational performance

[0013] Heating to about 1200°C, repeated high-temperature heating is prone to defects such as coarse grains, loose structure, and surface decarburization of the material, and "cracks" on the surface of the fins will be formed during severe extrusion deformation, resulting in waste products; when such " When the "crack" defect exists on the inner surface, there is a potential risk of leakage and explosion in the heat exchanger made of this finned tube

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