A kind of production method of thick wall seamless elbow

Abstract

The invention discloses a production method for a thick-wall seamless elbow. The production method for the thick-wall seamless elbow comprises the following steps of blanking, specifically, a seamlesssteel pipe with the specification same as that of the elbow is adopted as a base metal cutting blank, and the two end faces of the blank are symmetrically cut to be slopes with the angle of alpha; heating, specifically, the blank is heated to 860-1,050 DEG C; heading, specifically, the heated blank is put on an oblique blank heading tool, the blank is headed in a pressurizing manner, the outer perimeter and the wall thickness size of the blank are increased in the heading process, and meanwhile pre-bending is conducted; flattening, specifically, force is exerted to the headed blank in the vertical pre-bending center plane direction for flattening; and pressing forming, specifically, the flattened blank is arranged in an elbow mold, and the blank is extruded into the elbow in a hollow manner in the elbow mold. According to the production method for the thick-wall seamless elbow, the same-specification seamless steel pipe can be adopted as base metal for blanking, the material utilization rate is increased to 0.85, and raw materials can be saved by about 10% compared with an existing hot pressing technology; and multi-pass extruding in the prior art is abandoned, the technology process is improved and simplified, the production efficiency is improved, the raw materials are saved, and the economic benefit is obvious.

Description

Technical field [0001] The invention relates to an elbow processing technology, in particular to a production method for thick-walled seamless elbows with a ratio of wall thickness to diameter ≥ 0.08. Background technique [0002] The elbow is an important component in the piping system. At present, the elbow welding straight pipe method is used to realize the change of the direction of the piping system. At present, there are two main methods for producing seamless elbows: intermediate frequency expansion and hot pressing. Due to the limitation of core material and production technology, thick-walled elbows with a ratio of wall thickness to diameter ≥0.08 will lose if the intermediate frequency expansion is used. Economical and advanced. For thick-walled elbows with a ratio of wall thickness to diameter ≥ 0.1, the intermediate frequency expansion process completely loses its advantages. Therefore, the production of thick-walled elbows with a ratio of wall thickness to diameter ...

AI Technical Summary

Problems solved by technology

The above method has problems such as low material utilization rate (less than 0.78), difficult operation (mandrel and other tooling must be put in and taken out when the tube blank is about 1000°C), low production efficiency, etc.

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