CN108277384A - Have the high heat conduction Pb-Li-Pd lead lithium alloys of high high-temp stability - Google Patents

Abstract

The invention discloses the high heat conduction Pb Li Pd lead lithium alloys for having high high-temp stability and its processing technologys.According to weight percent, the ingredient of the alloy is：Li:1.2‑1.6wt.%,Pd:0.6‑0.8wt.%,Se:0.4‑0.6wt.%,Th:0.2 0.4wt.%, In:2.6‑3.5wt.%,Ce:0.2 0.5wt.%, surplus are lead.The lead lithium alloy has the high temperature stability performance that traditional shielding material metal does not have, and has high heat conduction ability.For fields such as core heap, medical radiation course shielding, nuclear waste disposals under tropical environment, it can effectively ensure the safe operation of nuclear reactor system, improve the system operation service life.

Description

Have the high heat conduction Pb-Li-Pd lead lithium alloys of high high-temp stability

Technical field

The present invention relates to technical field of alloy, specifically, being related to a kind of lead lithium alloy.

Background technology

In energy plaque increasingly weary 21st century, nuclear power will become most important cleaning, efficient, the reliable energy.Core During reactor operation, reactor core will generate radiation.It is wherein especially stronger with the penetration power of gamma-rays and neutron, thus can be to week Side object and personnel generate irradiation damage.Therefore effectively shielding gamma-rays and neutron be nuclear reactor improve security reliability must It is required that in all great meaning of national defence and civil field.

One national comprehensive strength is shown to nuclear energy uses, indicates the defense force and national economy water of country It is flat.In order to ensure the safe operation of nuclear reactor system, improve the system operation service life, it is necessary to shield to nuclear reactor system Processing is covered, with the nuclear screening facility with high reliability come attenuation ray.It is contemplated that as nuclear energy application expands increasingly, people Increasingly attention to safety and environmental protection.In rings such as the landfill disposals of nuclear fuel material storage and transportation, reactor operation to nuke rubbish On section, to nuclear screening material, more stringent requirements are proposed.

Shielding material is to design preparation according to its special applications in different nuclear reactions, and the shield effectiveness of material is Most important factor.In addition, the physical and mechanical property of material, anti-radiation performance, thermal stability etc. must also be considered. With fast reactor, power reactor and other increases for carrying radiation source application, it is anti-that traditional shielding material has been difficult to meet modern radiation The particular/special requirement of shield, as aviation and weapon field not only need material to have good comprehensive shielded performance, but also to material Mechanical and physical performance also has very high requirement.Structural and functional is always a big contradiction of shielding material design.

A large amount of research is had been carried out to shielding alloy material both at home and abroad, many shielding materials have been widely used. In general, most shielding alloy material contains lead either metal.Shielding metal has very unique performance：(1) Function admirable, moderate cost, technical maturity.In fields such as core oil explorations, there is larger application prospects.Have good multiple Radiation shield performance.(2) second phases will not cause alloy to soften, so as to make lead obtain due to stability height because keeping for a long time Strengthen to effective, can also keep higher intensity property at relatively high temperatures.(3) possess good ductility, Ke Yiyou Effect reduces the difficulty of processing of metal, meets the needs as Structural Engineering materials'use.

What people constantly pursued alloy property and the optimal combination of processing performance meets the requirement increasingly promoted.Currently, Multi-faceted wound nuclear reactor alloy material has been carried out by the effort of decades in developed countries such as America and Europe, Japan Newly.The product of the current shielding material alloy in China is also very single, cannot be applicable in the working environment for having temperature requirement.It opens Hair has property metal, and there are two types of methods, and one is addition alloying elements to strengthen matrix by solution strengthening, another Kind is mutually to form Al-matrixcomposites by the way that second-phase strength is added.In metal be added lithium after, by optimized alloy at Divide and proportioning can be so that metal has good multiple reflection shielding properties.

In melting and forming process oxidation easily occurs for lead lithium alloy, burning is even exploded, and not only gives the molding of part It causes damages with performance, also easily injures human body and pollution environment.One important directions of lead lithium alloy industrialization are exactly such as What prevents the oxidizing fire under its high temperature.At present frequently with chlorate flux protection method and inert gas shielding in metallurgy industry Method.But both methods has the defect that it is difficult to avoid that, is such as also easy to produce toxic gas pollution environment and flux is caused to be mingled with And damage alloy property.In addition, melting, casting equipment and complex process, increase cost.Lead lithium alloy is solved to melt in an atmosphere It is to add alloying element into lead lithium alloy that another approach of burning is generated when refining, reaches fire-retardant mesh by the method for alloying 's.

Its mechanism of alloying ignition-proof method is to add specific alloying element in lead lithium alloy fusion process to influence alloy The thermodynamics and dynamics process of oxidation forms dense oxidation film and nitride film with protective effect, reaches and prevents alloy acute The purpose of strong oxidation and nitridation, and the tendency of oxidizing fire of lead lithium alloy during following process substantially reduces, to Improve the process safety of lead lithium alloy.Lead lithium alloy not only has excellent strength character, and high temperature resistance is also much high In existing shielding material metal.

Invention content

The purpose of the present invention is to overcome the deficiency in the prior art, provide one kind can under 350-400 degree atmospheric conditions into The high heat conduction Pb-Li-Pd lead lithium alloy and its processing technology for having high high-temp stability of row melting.And it is molten in this temperature range The alloy final products of refining have excellent elevated temperature strength and high screening ability required for lead Zinc-lithium alloy material.This method also has There is the characteristics of production cost is low, convenient for large-scale production.

To achieve the goals above, the present invention adopts the following technical scheme that：

A kind of high heat conduction Pb-Li-Pd lead lithium alloys having high high-temp stability.By weight percentage, the group of alloy becomes： Li: 1.2-1.6wt.%,Pd:0.6-0.8wt.%,Se:0.4-0.6wt.%,Th:0.2-0.4wt.%, In:2.6-3.5wt.%, Ce:0.2-0.5wt.%, surplus are lead.The lead lithium alloy is in fusion process because volatilizing and forming the reasons such as clinker and lose Weight is in 1.0-3.0wt.% or so.

The preparation method of the above-mentioned high heat conduction Pb-Li-Pd lead lithium alloys for having high high-temp stability, includes the following steps： As above the raw material matched is added in the electric induction furnace of atmosphere protection, and uses silicon carbide crucible；Sensing heating is to 350-400 Degree forms alloy solution, and is sufficiently stirred 10 minutes or so using electromagnetic agitation effect；Alloy liquid is kept the temperature in 350-400 degree Standing is cast to progress semi-continuous casting in the same level equipment of heat top and is moved down at required side's ingot and billet, ingot casting after ten minutes Speed is 8-10m/min.Ingot casting is subjected to deformation process at room temperature, amount is 10-15% under every time rolling；Every 3 passes It needs to carry out an intermediate heat-treatment to eliminate processing hardening, technique is：148 degree, 2.4 hours；At final heat after rolling Science and engineering skill is：Vacuum solid solution handles 215 degree, 2.0 hours；Vacuum aging handles 130 degree, 1.5 hours.

Compared with prior art, the present invention has the advantages that：

（1）Patent of the present invention can't fully meet existing demand for the high-temperature behavior of current shielding material metal Present situation provides a kind of novel materialogy solution.The alloy has extremely excellent flame retardant property, can reach 5 hours are stood without significantly burning under atmospheric environment in 350-400 temperature ranges.It is stirred to liquid alloy During the melt treatments such as mixing, blowing, after its skin covering of the surface is destroyed because being vigorously stirred, can rapid regeneration, successfully hinder alloy Burning.And the weight that the lead lithium alloy loses in fusion process because of the reasons such as volatilization and formation clinker is less than 3.0wt.% Left and right.

（2）The addition of lithium allows the density of density ratio majority alloy of lead lithium alloy will be low.And with the increasing of lithium content Add, density can also further decrease.Lead lithium alloy has very high intensity, intensity not to occur because of the increase of lithium content Significant change, and the intensity of alloy can be further increased by adding the elements such as copper, magnesium, zinc.Lead lithium alloy possesses very high Rigidity, non-deformability is strong, and rigidity can also be further increased with the increase of lithium content.

（3）The alloy successfully solves physics, chemical compatibility and interface compatibility between lead and alloying element and asks Topic, overcomes the difference in specific gravity between constituent element, realizes alloying element and alloy mutually being uniformly distributed in lead base body.With low liquid Solid phase solidification temperature range can solve the skills such as hot cracking tendency when casting is big, and casting cavity is low with loose apparent product yield rate Art problem.

（4）Relative to traditional shielding material metal, the height for having high high-temp stability of present patent application protection Heat conduction Pb-Li-Pd lead lithium alloys have extremely excellent high-temperature behavior.At room temperature, the tensile strength of the alloy reaches 320- 340MPa.At 100 degree, the tensile strength of the alloy reaches 280-320MPa.And the room temperature of traditional shielding material metal and Tensile strength under 100 degree is respectively 230-250MPa and 150-180MPa.The heat transfer coefficient of the material is 40-45W/m ﹒ K, high In the heat transfer coefficient 35W/m ﹒ K of pure lead.And the heat transfer coefficient of general metal is less than the 60% of pure lead.For under tropical environment Core heap, medical radiation course shielding, the fields such as nuclear waste disposal, can effectively ensure nuclear reactor system safe operation, Improve the system operation service life.

Specific implementation mode

Embodiment 1

A kind of high heat conduction Pb-Li-Pd lead lithium alloys having high high-temp stability in 350 degree of meltings.By weight percentage, it closes Gold chemical composition be：Li: 1.5wt.%,Pd:0.6wt.%,Se:0.4wt.%,Th:0.2wt.%, In:2.8wt.%, Ce: 0.3wt.%, surplus are lead.The preparation method of alloy：As above the raw material matched is added in the electric induction furnace of atmosphere protection, and Using silicon carbide crucible；Sensing heating forms alloy solution to 350 degree, and is sufficiently stirred 10 minutes left sides using electromagnetic agitation effect It is right；Alloy liquid is kept the temperature to stand to be cast to after ten minutes in the same level equipment of heat top at 350 degree and carries out semi-continuous casting into institute The square ingot and billet needed, it is 8m/min that ingot casting, which moves down speed,.Ingot casting is subjected to deformation process at room temperature, under every time rolling Amount is 12%；Every 3 passes need to carry out an intermediate heat-treatment to eliminate processing hardening, and technique is：It is 148 degree, 2.4 small When；Final Heat Treatment Process after rolling is：Vacuum solid solution handles 215 degree, 2.0 hours；Vacuum aging handles 130 degree, and 1.5 is small When.

Relative to traditional shielding material metal, the high heat conduction for having high high-temp stability of present patent application protection Pb-Li-Pd lead lithium alloys have extremely excellent high-temperature behavior.At room temperature, the tensile strength of the alloy reaches 336MPa. At 100 degree, the tensile strength of the alloy reaches 292MPa.And it is anti-under the room temperature and 100 degree of traditional shielding material metal Tensile strength is respectively 230-250MPa and 150-180MPa.The heat transfer coefficient of the material is 42W/m ﹒ K, is higher than the heat transfer system of pure lead Number 35W/m ﹒ K.And the heat transfer coefficient of general metal is less than the 60% of pure lead.For core heap, the medical radiation under tropical environment The fields such as source shielding, nuclear waste disposal can effectively ensure the safe operation of nuclear reactor system, improve the system operation longevity Life.The weight that the lead lithium alloy loses in fusion process because of the reasons such as volatilization and formation clinker is in 1.5wt.% or so.

Embodiment 2

A kind of high heat conduction Pb-Li-Pd lead lithium alloys having high high-temp stability in 370 degree of meltings.By weight percentage, it closes Gold chemical composition be：Li: 1.4wt.%,Pd:0.6wt.%,Se:0.5wt.%,Th:0.3wt.%, In:2.8wt.%, Ce: 0.3wt.%, surplus are lead.The preparation method of alloy：As above the raw material matched is added in the electric induction furnace of atmosphere protection, and Using silicon carbide crucible；Sensing heating forms alloy solution to 370 degree, and is sufficiently stirred 10 minutes left sides using electromagnetic agitation effect It is right；Alloy liquid is kept the temperature to stand to be cast to after ten minutes in the same level equipment of heat top at 370 degree and carries out semi-continuous casting into institute The square ingot and billet needed, it is 10m/min that ingot casting, which moves down speed,.Ingot casting is subjected to deformation process at room temperature, every time is rolled Lower amount is 12%；Every 3 passes need to carry out an intermediate heat-treatment to eliminate processing hardening, and technique is：148 degree, 2.4 Hour；Final Heat Treatment Process after rolling is：Vacuum solid solution handles 215 degree, 2.0 hours；130 degree of vacuum aging processing, 1.5 Hour.

Relative to traditional shielding material metal, the high heat conduction for having high high-temp stability of present patent application protection Pb-Li-Pd lead lithium alloys have extremely excellent high-temperature behavior.At room temperature, the tensile strength of the alloy reaches 335MPa. At 100 degree, the tensile strength of the alloy reaches 282MPa.And it is anti-under the room temperature and 100 degree of traditional shielding material metal Tensile strength is respectively 230-250MPa and 150-180MPa.The heat transfer coefficient of the material is 45W/m ﹒ K, is higher than the heat transfer system of pure lead Number 35W/m ﹒ K.And the heat transfer coefficient of general metal is less than the 60% of pure lead.For core heap, the medical radiation under tropical environment The fields such as source shielding, nuclear waste disposal can effectively ensure the safe operation of nuclear reactor system, improve the system operation longevity Life.The weight that the lead lithium alloy loses in fusion process because of the reasons such as volatilization and formation clinker is in 1.4wt.% or so.

Embodiment 3

It is a kind of to have the high heat conduction Pb-Li-Pd lead lithium alloy of high high-temp stability by weight percentage in 390 degree of meltings, it closes Gold chemical composition be：Li: 1.3wt.%,Pd:0.7wt.%,Se:0.4wt.%,Th:0.2wt.%, In:2.9wt.%, Ce: 0.4wt.%, surplus are lead.The preparation method of alloy：As above the raw material matched is added in the electric induction furnace of atmosphere protection, and Using silicon carbide crucible；Sensing heating forms alloy solution to 390 degree, and is sufficiently stirred 10 minutes left sides using electromagnetic agitation effect It is right；Alloy liquid is kept the temperature to stand to be cast to after ten minutes in the same level equipment of heat top at 390 degree and carries out semi-continuous casting into institute The square ingot and billet needed, it is 10m/min that ingot casting, which moves down speed,.Ingot casting is subjected to deformation process at room temperature, every time is rolled Lower amount is 13%；Every 3 passes need to carry out an intermediate heat-treatment to eliminate processing hardening, and technique is：148 degree, 2.4 Hour；Final Heat Treatment Process after rolling is：Vacuum solid solution handles 215 degree, 2.0 hours；130 degree of vacuum aging processing, 1.5 Hour.

Relative to traditional shielding material metal, the high heat conduction for having high high-temp stability of present patent application protection Pb-Li-Pd lead lithium alloys have extremely excellent high-temperature behavior.At room temperature, the tensile strength of the alloy reaches 338MPa. At 100 degree, the tensile strength of the alloy reaches 284MPa.And it is anti-under the room temperature and 100 degree of traditional shielding material metal Tensile strength is respectively 230-250MPa and 150-180MPa.The heat transfer coefficient of the material is 40W/m ﹒ K, is higher than the heat transfer system of pure lead Number 35W/m ﹒ K.And the heat transfer coefficient of general metal is less than the 60% of pure lead.For core heap, the medical radiation under tropical environment The fields such as source shielding, nuclear waste disposal can effectively ensure the safe operation of nuclear reactor system, improve the system operation longevity Life.The weight that the lead lithium alloy loses in fusion process because of the reasons such as volatilization and formation clinker is in 1.2wt.% or so.

Claims (3)

1. a kind of high heat conduction Pb-Li-Pd lead lithium alloys having high high-temp stability；According to weight percent, the alloy at It is divided into：Li: 1.2-1.6wt.%,Pd:0.6-0.8wt.%,Se:0.4-0.6wt.%,Th:0.2-0.4wt.%, In:2.6- 3.5wt.%, Ce:0.2-0.5wt.%, surplus are lead.

2. having the high heat conduction Pb-Li-Pd lead lithium alloys of high high-temp stability according to claim 1, it is characterised in that packet Include following steps：As above the raw material matched is added in the electric induction furnace of atmosphere protection, and uses silicon carbide crucible；Induction adds Heat forms alloy solution to 350-400 degree, and is sufficiently stirred 10 minutes or so using electromagnetic agitation effect；Alloy liquid is existed The heat preservation of 350-400 degree stand be cast to after ten minutes in the same level equipment of heat top carry out semi-continuous casting at required side's ingot and Billet, it is 8-10m/min that ingot casting, which moves down speed,.

3. having the high heat conduction Pb-Li-Pd lead lithium alloys of high high-temp stability according to claim 1, it is characterised in that packet Containing following procedure of processing：Ingot casting is subjected to deformation process at room temperature, amount is 10-15% under every time rolling；Every 3 passes It needs to carry out an intermediate heat-treatment to eliminate processing hardening, technique is：148 degree, 2.4 hours；At final heat after rolling Science and engineering skill is：Vacuum solid solution handles 215 degree, 2.0 hours；Vacuum aging handles 130 degree, 1.5 hours.