CN104550311A

CN104550311A - Method for producing superconducting niobium pipe

Info

Publication number: CN104550311A
Application number: CN201410734297.4A
Authority: CN
Inventors: 李积贤; 汪凯; 赵红运; 张九海; 梁立; 安刚; 崔新云
Original assignee: NINGXIA ORIENT SUPERCONDUCTING TECHNOLOGY Co Ltd; Ningxia Orient Tantalum Industry Co Ltd
Current assignee: NINGXIA ORIENT SUPERCONDUCTING TECHNOLOGY Co Ltd; Ningxia Orient Tantalum Industry Co Ltd
Priority date: 2014-12-05
Filing date: 2014-12-05
Publication date: 2015-04-29
Anticipated expiration: 2034-12-05
Also published as: CN104550311B

Abstract

The invention relates to a method for producing a superconducting niobium pipe. The method is characterized by comprising the following steps: drilling a cylindrical high-purity niobium cast ingot to obtain a hollow ingot, and extruding the hollow ingot at room temperature so as to obtain a pipe billet; rolling the pipe billet to obtain the finished niobium pipe. According to the method disclosed by the invention, the production of pure niobium pipes for superconducting accelerators is realized by adopting room temperature forward extrusion and pipe rolling pressure working modes, and the high-purity niobium pipes of which the RRR value is more than or equal to 300 can be machined under the conditions that a process is simple and a manufacturing tool is not needed. According to the method disclosed by the invention, the pipe billet is extruded by adopting a room temperature forward extrusion method, the material heating degree in the extrusion process is controlled by controlling the extrusion speed, and the severe loss of the RRR value can be effectively avoided; and moreover, the finished pipes with the advantages of high dimensional accuracy and low ellipticity can be manufactured by utilizing a multi-roller pipe mill.

Description

A kind of method of producing Niobium Superconducting tubing

Technical field

The present invention relates to a kind of method of producing Niobium Superconducting tubing.

Background technology

Superconducting accelerator is the deep cooling low temperature charged particle acceleration equipment of complicated, a current new and high technology of condensing, it is the Main Means of research Modem Nuclear Physics, high-energy physics, it has become the particle accelerator technology of current advanced person, its critical component radio frequency Superconducting cavity LINAC has suitable huge market demand, is making great efforts to carry out the research of radio frequency Superconducting cavity LINAC and promote its industrialization process based on the developed country of Germany, the U.S. and Japan.American plan sets up FRIB (the isotopic ion source accelerator) device that expection was built up in 10 years, cost is 500,000,000 5 thousand ten thousand dollars, this device can produce the rare isotope be only present in the supernova of blast, to the active force studied between proton and neutron be used for, and can be applied in material science and medical domain.Crucial component materials made by High-purity Niobium tubing in frequency Superconducting cavity LINAC.

The key parameter characterizing superconducting accelerator High-purity Niobium tubing superconductivity is RRR value (i.e. the residual resistivity of material at 4.2K temperature), and it is better that General Requirements RRR value is greater than 300, RRR value higher then tubing superconductivity.And the principal element affecting High-purity Niobium tubing superconductivity in processing is from ingot casting to the temperature rise degree finished product process, in processing, the decay of temperature rise higher then RRR value is more serious, so processing method is most important with the production of pure niobium tubing to superconducting accelerator.

At present, the superconducting accelerator production technology of pure niobium tubing in the whole world mainly contains sheet material welding, backward extrusion method, forging reaming method and deep drawing methods four class, but there is lower column defects: 1) sheet material welding requires higher to sheet material glacing flatness, solder technology and circularity guarantee etc., and need first ingot casting to be worked into sheet material and to weld again, the production cycle is long; 2) precision prescribed of backward extrusion method to extrusion equipment frock and lubricating system is very high, and finished product needs machined, and stock utilization is low; 3) there is the problem that stock utilization is low, production efficiency slow and frock cost is high in forging reaming method and deep drawing methods.And above four kinds of methods are all difficult to realize diameter producing of below 50mm, the above tubing of wall thickness 3mm.

Summary of the invention

The object of this invention is to provide a kind of method of producing Niobium Superconducting tubing, effectively can avoid the heavy losses of niobium tubing RRR value in process and significantly improve the utilization rate of material and the working (machining) efficiency of product.

Produce a method for Niobium Superconducting tubing, its special feature is, comprises the steps: that getting columned High-purity Niobium ingot casting holes, obtain hollow ingot, at room temperature hollow ingot extruded thus obtain pipe, then pipe being rolled, namely obtaining finished product niobium tubing.

Wherein pipe first uses machining equipment or polissoir to eliminate except the extrusion defect on pipe before being rolled.

Detect its RRR value after wherein obtaining finished product niobium tubing and should be greater than 250.

Wherein pressing steps specifically extrudes hollow ingot with the extruder of 3500 tons or 1650 tons.

The pressure processing mode that present invention employs " room temperature forward extrusion+tube rolling " realizes the production of superconducting accelerator with pure niobium tubing, under simply and not needing the prerequisite of making frock, can process the High-purity Niobium tubing of RRR value >=300 in technique.The present invention adopts room temperature forward extrusion method extrusion tube blank, controlling material temperature rise degree in extrusion process, effectively can avoid RRR value heavy losses by controlling extrusion speed; Utilize multiple roll pipe mill to produce dimensional accuracy is high, ovality is little finished product tubing.The present invention adopts simple pressure processing method, do not need to make auxiliary mould, less demanding to equipment hydraulic pressure equally accurate, both can realize diameter the processing of below 120mm, RRR value>=300 High-purity Niobium tubing, can bring up to more than 40% by stock utilization by about 30% again, and the inventive method significantly can improve the working (machining) efficiency of product simultaneously.

Detailed description of the invention

Embodiment 1:

Get the High-purity Niobium ingot casting of 250 × L0mm (cylindric) → (lathe or Linear cut are at ingot casting central authorities drill diameter the hole of 100mm) boring 100mm → 250 × 100 × L0mm hollow ingot (hollow pipe ingot) → room temperature extruding (mode by diameter reduces) → 130 × 98 × L1mm (size after extruding) extrusion tube blank → pipe surfaces externally and internally and pipe extrusion defect removal (lathe or polishing machine, sawing machine or Linear cut) end to end → 126 × 100 × L2mm pipe → tube rolling → 120 × 95 × L3mm production tube → detection RRR value.

The niobium tubing of large gauge (130mm > diameter > 100mm) can be obtained by this technique, and the lumber recovery of the tubing of extrusion process+rolling process (more than 40%) is higher than other processing mode (lower than 35%), and RRR value meets the demands.

Embodiment 2:

Get 155 × L0mm High-purity Niobium ingot casting (cylindric) → boring (lathe or Linear cut are at ingot casting central authorities drill diameter for 70mm the hole of 100mm) → 155 × 70 × L0mm hollow ingot (hollow pipe ingot) → room temperature extruding (mode by diameter reduces) → 95 × 69 × L1mm extrusion tube blank (size after extruding) → pipe surfaces externally and internally and pipe extrusion defect removal (lathe or polishing machine, sawing machine or Linear cut) end to end → 94 × 70 × L2mm pipe → tube rolling → tube rolling ( 82 × 8 < pipe thickness > → 67 × 6 → 54 × 5 → 52 × 4.5 →) 50 × 4 × L3mm production tube → detection RRR value.

The niobium tubing of middle specification (100mm > diameter > 30mm) can be obtained by this technique, and the lumber recovery of the tubing of extrusion process+rolling process (more than 40%) is higher than other processing mode (lower than 35%), and RRR value meets the demands.

In above-mentioned all embodiments, pressing steps adopts the extruder of 3500 tons or 1650 tons.

Claims

1. produce a method for Niobium Superconducting tubing, it is characterized in that, comprise the steps: that getting columned High-purity Niobium ingot casting holes, obtain hollow ingot, at room temperature hollow ingot extruded thus obtain pipe, then pipe being rolled, namely obtaining finished product niobium tubing.

2. a kind of method of producing Niobium Superconducting tubing as claimed in claim 1, is characterized in that: wherein pipe first uses machining equipment or polissoir to eliminate except the extrusion defect on pipe before being rolled.

3. a kind of method of producing Niobium Superconducting tubing as claimed in claim 1, is characterized in that: detecting its RRR value after wherein obtaining finished product niobium tubing should be greater than 250.

4. a kind of method of producing Niobium Superconducting tubing as claimed in claim 1, is characterized in that: wherein pressing steps specifically extrudes hollow ingot with the extruder of 3500 tons or 1650 tons.