Forming method of precise high-temperature alloy pipe with small caliber and thick wall for aviation

Abstract

The invention discloses a forming method of a precise high-temperature alloy pipe with small caliber and thick wall for aviation. The forming method comprises the following steps: S1: cold rolling: carrying out multi-pass cold rolling on a qualified seamless tube to obtain a tube blank in transitional specification, wherein the outer diameter of the tube blank in the transitional specification is 1.14-1.17 times of that of a finished tube, the wall thickness of the tube blank is 0.97-0.985 times of that of the finished tube, and the dimensional deviation is controlled within a range of plus or minus 0.03mm; S2: manufacturing a pointed end: carrying out degreasing, heat treatment, acid cleaning, straightening and UT (ultrasonic) flaw detection on the tube blank with transitional specification sequentially, selecting the qualified tube blank obtained after UT flaw detection, and welding a pointed end with conicity at the end part of the qualified tube blank; S3: empty sinking: drawing the tube blank by the pointed end and deforming the tube blank under the extrusion of an outer mold to obtain a finished tube. The forming method makes up the technical gap of domestically producing the precise high-temperature alloy pipe with small caliber and thick wall, and has important economic benefit on the research and the production of a domestic aero-engine.

Description

technical field [0001] The invention relates to a forming method of a small-diameter thick-walled high-temperature alloy pipe, in particular to a forming method of a precision small-diameter thick-walled high-temperature alloy pipe used in an aircraft engine oil supply system. [0002] Background technique [0003] High-temperature alloy tubes for aviation are mainly used in the fuel supply system of aircraft engines. Due to their small specifications (outer diameter ≤ 8.5mm, wall thickness ≥ 2.3mm) and high precision (inner diameter tolerance is ±0.03mm, the detection method for inner diameter tolerance is A standard steel ball whose diameter is the lower tolerance of the inner diameter of the alloy tube is inserted into the alloy tube, and the steel ball can enter the lumen smoothly, while a standard steel ball whose diameter is the upper tolerance of the inner diameter of the alloy tube cannot enter the lumen; the outer diameter tolerance is ±0.04 ), large length (single...

AI Technical Summary

Problems solved by technology

[0003] High-temperature alloy tubes for aviation are mainly used in the fuel supply system of aircraft engines. Due to their small specifications (outer diameter ≤ 8.5mm, wall thickness ≥ 2.3mm) and high precision (inner diameter tolerance is ±0.03mm, the detection method for inner diameter tolerance is A standard steel ball whose diameter is the lower tolerance of the inner diameter of the alloy tube is inserted into the alloy tube, and the steel ball can enter the lumen smoothly, while a standard steel ball whose diameter is the upper tolerance of the inner diameter of the alloy tube cannot enter the lumen; the outer diameter tolerance is ±0.04 ), large length (single length ≥ 3m), so it is difficult to manufacture, and the country can only rely on imports for a long time, and the import price is 6 million yuan / ton, which is expensive and seriously restricts the domestic research and development and production of aero-engines

The difficulty in the production of aviation superalloy pipes lies in the forming technology. In China, spray forming technology, extrusion forming technology, and jacking forming technology have been used for development, but there are no reports of successful trial production.