Processing technology of Omega seamless steel pipe

Abstract

The invention discloses a processing technology of an omega seamless steel pipe. The processing technology comprises the following steps that (1) a blank is preprocessed, specifically, a medium-frequency induction heater is adopted, the heating temperature is 1160-1180 DEG C, and heat is preserved for 2-3 min; (2) a hot extrusion die conducts manufacturing, specifically, a die cavity sleeve and a hot extrusion core rod form a die cavity of the steel pipe, and an extrusion flow guide hole is formed in the position over the central line of the die cavity; (3) the blank is subjected to excircle turning, and a hole is drilled in the center of the blank; (4) a lubricating agent is smeared on the die, and a primary pipe is obtained after hot extrusion; (5) the primary pipe is subjected to straightness shaping; (6) stress relief annealing is conducted, the heating and holding temperature T is 700-720 DEG C, and the heat preservation time is not shorter than 2 h; (7) acid pickling and phosphating are conducted; (8) cold drawing is conducted, specifically, a 120 T speed regulating type drawing machine is selected, and the drawing linear speed is lower than or equal to 2.5 m / min; (9) a secondary productive cycle is carried out, and after stress relief annealing, steel pipe acid pickling and phosphating lubrication, finished product cold drawing is conducted till the finished product dimension is reached; (10) normalizing treatment is conducted; and (11) straightening is conducted, and the effect that the straightness is less than or equal to 0.5 mm / m, and the torsion resistance is less than or equal to 0.5 mm / m is ensured. Through the processing technology, the high-quality omega seamless steel pipe can be produced efficiently.

Description

technical field [0001] The invention relates to the technical field of seamless steel pipe processing, in particular to a processing technology for omega seamless steel pipes. Background technique [0002] Omega seamless steel pipe is a heat exchanger tube for nuclear power plants, the material is 15CrMoG, the shape is as figure 1 As shown, the overall shape is Ω. Due to the special shape of Omega seamless steel pipe, due to the limitation of processing equipment and technology, the finished seamless steel pipe is not satisfactory in terms of specification, length, straightness, twist and surface quality, and the finished product efficiency is also low, so it can only be used for a long time Relying on imports, the price is high and cannot meet the needs of the market. Contents of the invention [0003] The technical problem mainly solved by the present invention is to provide a processing technology of omega seamless steel pipe, which can produce omega seamless steel pi...

AI Technical Summary

Problems solved by technology

Due to the special shape of Omega seamless steel pipe, due to the limitation of processing equipment and technology, the finished seamless steel pipe is unsatisfactory in specification, length, straightness, twist and surface quality, and the finished product efficiency is also low, so it can only be used for a long time Relying on imports, high prices, unable to meet market demand

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