CN101157998A

CN101157998A - Tin-brass alloy containing rare earth

Info

Publication number: CN101157998A
Application number: CNA2007101566539A
Authority: CN
Inventors: 曹建国; 程建奕; 赵学龙
Original assignee: Zhejiang Hailiang Co Ltd
Current assignee: Zhejiang Hailiang Co Ltd
Priority date: 2007-11-13
Filing date: 2007-11-13
Publication date: 2008-04-09

Abstract

The invention relates to a rare earth stannum copper alloy, belonging to the technical field of the alloying of metal material and the anti-corrosion; the invention comprises copper, zinc, stannum, aluminum, nickel, manganese, antimony, boron, mischmetal containing mainly light rare earth elements such as lanthanum and cerium, each component element takes up the weight proportion as: copper 69-71%, stannum 0.5-1%, aluminum 0.1-0.5%, nickel 0.1-0.5%, manganese 0.1-0.6%, antimony 0.01-0.05%, boron 0.002-0.02%, mischmetal containing mainly light rare earth elements such as lanthanum and cerium 0.02-0.2%, the rest is taken by zinc and impurity with the total volume of no greater than 0.05%, the sum up of each component element is 100%. The invention aiming at the high corrosion resistance requirements by a condenser tube for heat exchange, via optimized design and multiple test, is finished to improve the anti-stress corrosion rupture performance, and level up the anti high C1-, NH4+, S2- ion density corrosion performance of polluted water.

Description

Tin-brass alloy containing rare earth

Technical field

The present invention relates to a kind of tin-brass alloy containing rare earth, belong to the alloying and the material antiseptic erosion technical field of metallic substance.

Background technology

Copper alloys such as HSn70-1, HA177-2 brass have good heat conduction and corrosion resisting property, therefore are widely used in heat exchanger prolong material in Coastal Power Plant, the naval vessel.In order to suppress the selectivity dezincify dissolving of brass, generally adopt micro-As of interpolation and B to improve corrosion resisting property for many years.But As has severe toxicity, is the unfriendly material of a kind of environment, and its volatilization in process of production is extremely harmful to HUMAN HEALTH, therefore will avoid using.There are some researches show, only add the dezincify that boron can not suppress brass fully, therefore further improve the corrosion resisting property of one-ton brass and find suitable alloy element to replace deleterious arsenic very necessary.And rare earth can improve the corrosion resisting property of copper and copper alloy, but the research of copper and corrosion of copper alloy Effect on Performance be can not show a candle to physicals and Study on mechanical properties is extensive like that.Simultaneously, and when ammonia and oxygen coexistence, ammonia is the sensitive media of copper alloy stress corrosion cracking and corrosion fatigue, and in the both sides of heat exchanger air removal section copper pipe vapour side and supporting clapboard, owing to the localized concentrations of regulating the ammonia of introducing to water ph value, ammonia content in the water coolant exceeds tens of times than main condensate (ammonia quantity is 1-10mg/L), makes condenser copper tube produce serious ammonia corrosion, and seriously corroded can cause local leakage.Therefore studying a kind of high anti-corrosion tin-brass alloy that contains rare earth that can substitute deleterious arsenic has very important significance.

At present domestic and international discloseder patent about one-ton brass, as: 85106324,200610039282, all are the one-ton brass that add arsenic.Tin-brass alloys of these invention preparations all have corrosion resisting property preferably, are suitable for doing heat exchanger and condenser tube, but they all are to contain arsenic tin-brass alloy material with boron, aluminium or with nickel, manganese as additive.Therefore in preparation process and use unavoidably to HUMAN HEALTH and environment toxic side effect.

Summary of the invention

The object of the present invention is to provide a kind of formulating of recipe reasonable, have the tin-brass alloy containing rare earth of good anti-Cl-and NH3+ ion etching performance.

The present invention is a tin-brass alloy containing rare earth, comprise copper, zinc, it is characterized in that also comprising simultaneously tin (Sn), aluminium (Al), nickel (Ni), manganese (Mn), antimony (Sb), boron (B), with lanthanum (La), cerium lightweight rare earth elements such as (Ce) is main norium (Re), and the composition of each component is respectively by weight percentage: copper (Cu) 69～71%, tin (Sn) 0.5～1%, aluminium (Al) 0.1～0.5%, nickel (Ni) 0.1～0.5%, manganese (Mn) 0.1～0.6%, antimony (Sb) 0.01～0.05%, boron (B) 0.002～0.02%, with lanthanum (La), cerium lightweight rare earth elements such as (Ce) is main norium (Re) 0.02～0.2%, and all the other are that zinc (Zn) and total amount are not more than 0.05% impurity, and the weight percent summation of each component is 100%.

In copper zinc alloy, add tin (Sn); can form fine and close tindioxide protective membrane at alloy surface; can significantly improve brass anti-Dezincification corrosion ability in seawater, and improve the corrosive nature of sea water resistance, anti-marine atmosphere greatly, but the too high frangible compounds that then easily forms tin.The present invention relatively reaches optimization through repetition test, determines that tin (Sn) content is 0.5～1%.

In copper zinc alloy, add aluminium (Al), can make the crystal grain of matrix phase obtain refinement and reinforcement, improve the intensity and the plasticity of material, and bigger at the ionization tendency of alloy surface than zinc, oxygen preferential and in the contact medium combines and forms firm oxide film, and the corrosion resisting property of material is improved.But the plasticity of alloy is sharply reduced, worsened the cold-forming property of alloy.The present invention relatively reaches optimization through repetition test, and the content of determining aluminium is 0.1～0.5%.

In copper zinc alloy, add nickel (Ni) element, can improve brass alloys intensity, toughness and stress corrosion resistant disruptive ability, also can improve the hot and cold processing characteristics of brass simultaneously.The present invention relatively reaches optimization through repetition test, and the content of determining nickel element is 0.1～0.5%.

In copper zinc alloy, add manganese (Mn) element, can play the solution strengthening effect, can with elements in conjunction such as aluminium, zinc-nickel, further intensity, hardness, the wear resistance of strongthener, the corrosion resisting property of raising in seawater, chloride soln and superheated vapour can also stop dezincification of brass.The present invention relatively reaches optimization through repetition test, and the content of determining manganese element is 0.1～0.6%.

In copper zinc alloy, add antimony (Sb) element, its role is to form Sb ₂O ₃Oxide film and stop the optimum solvation of zinc.But the solubleness of antimony in copper sharply reduces along with the reduction of temperature, is less than at 0.05% o'clock at its content, will form brittle Cu ₂Sb is net distribution on crystal boundary, makes brass at the hot and cold embrittlement in man-hour that adds.The present invention relatively reaches optimization through repetition test, and the content of determining antimony element is 0.01～0.05%.

Add boron (B) element of trace in copper zinc alloy, its effect has two: at first, boron can crystal grain thinning, improves intensity, hardness and the wear-corrosion resistance of brass.In addition, the boron atom is easy to fill up the divacancy that produces after the dezincify, thereby stops up the passage of zinc to external diffusion, reduces the erosion rate of dezincification of brass.The present invention is through repetition test comparison, optimization and biliographic data, and the suitable content of determining boron is 0.002～0.02%.

Add rare earth (Re) element of trace in copper zinc alloy, its effect has three: the first, and rare earth is the intensive reductor, and the rare earth oxide of generation is solid phase and floats on the liquid phase surface, and enters slag and be removed mutually, thereby purifies copper liquid, reaches the purpose of deoxygenation; The second, rare earth can crystal grain thinning, thereby improves the intensity of alloy; The 3rd, rare earth chemistry character is active, can also form oxide film in base metal surface, stops the zinc atom diffusion, suppresses the dissolving of copper, zinc, thereby improves its corrosion resisting property.But it is excessive that rare earth adds, harmful on the contrary to mechanical property, the corrosion resistance nature of alloy.The present invention is through repetition test comparison, optimization and biliographic data, and the suitable content of determining rare earth element is 0.02～0.2%.

The present invention is directed to heat exchanger prolong high anti-corrosion energy requirement, with the copper zinc alloy is the base alloy metal, add a spot of tin, aluminium, nickel, manganese, and adding micronutrient boron, rare earth and antimony, relatively develop through optimization design and test of many times, compare with existing one-ton brass, have following outstanding advantage and positively effect:

1. be a kind of high anti-corrosion one-ton brass material, can satisfy the needs of heat exchanger, be particularly suitable for as heat exchanger and prolong with condensation tubing.

2. by trace elements such as compound interpolation rare earth, antimony, substituted highly toxic arsenic element, and improved the anti-Cl of containing of alloy ^-, NH ₄ ⁺, S ^2-The sea-water corrosion performance.

3. on the basis of HSn70-1 alloy, add trace elements such as boron, nickel, manganese, aluminium, make alloy at stress corrosion resistant disruptive ability, anti-Cl ^-, NH ₄ ⁺, S ^2-The corrosive power of the polluted water that ionic concn is high is waited until further raising, and its scope of application is more more extensive than HSn70-1A and HSn70-1B.

Description of drawings

Fig. 1 be the embodiment of the invention 1 preparation contain erosion profile SEM and the X-ray energy spectrum analysis in NaCl (3.5%) solution of rare earth one-ton brass, wherein: a is an erosion profile; B is the X-ray energy spectrum line scanning.

Fig. 2 is that the embodiment of the invention 1 and 2 preparations two kinds contain the rare earth one-ton brass at NaCl (3.5%)+NH ₄Erosion profile SEM and X-ray energy spectrum analysis in Cl (0.5mol/L) solution, wherein: a and b are respectively erosion profile and the X-ray energy spectrum line scanning of embodiment 1, and c and d are respectively erosion profile and the X-ray energy spectrum line scanning of embodiment 2.

Embodiment

Below 2 embodiment of the present invention are listed as follows (seeing Table 2) with the composition (seeing Table 1) of conventional products HSn70-1A (being Comparative Examples 1) and two Comparative Examples each components of HSn70-1B (being Comparative Examples 2) in the market and the contrast of the corrosion resistance nature index in different corrosive mediums, to further specify excellent properties of the present invention.

The chemical ingredients of table 1 embodiment and Comparative Examples

	Chemical ingredients (wt%)
	Chemical ingredients (wt%)										Cu	Al	Sn	Ni	As	B	Mn	Sb	RE	Zn
	Embodiment 1	70	0.45	1	0.15	-	0.003	0.56	0.03	0.05	Cu	Al	Sn	Ni	As	B	Mn	Sb	RE	Zn	Surplus
Embodiment 2	Embodiment 1	70	0.45	1	0.15	-	0.003	0.56	0.03	0.05	70	0.45	1	0.15	-	0.003	0.56	0.03	0.1	Surplus	Surplus
Embodiment 2	Comparative Examples 1	70.1	-	0.98	-	0.054	-	-	-	-	70	0.45	1	0.15	-	0.003	0.56	0.03	0.1	Surplus	Surplus
Comparative Examples 2	Comparative Examples 1	70.1	-	0.98	-	0.054	-	-	-	-	69.9	-	1.02	-	0.047	0.009	-	-	-	Surplus	Surplus

Table 2 embodiment and the Comparative Examples static etch rate (mm/a) in different media

	Erosion rate among the NaCl (3.5%)	NaCl(3.5％)+Na ₂Erosion rate among the S (1g/L)	NaCl(3.5％)+NH ₄Erosion rate among the Cl (0.5mol/L)
	Erosion rate among the NaCl (3.5%)	NaCl(3.5％)+Na ₂Erosion rate among the S (1g/L)	NaCl(3.5％)+NH ₄Erosion rate among the Cl (0.5mol/L)	Embodiment 1	0.0088	0.0023	0.23948
Embodiment 2	0.0115	0.0021	0.18110	Embodiment 1	0.0088	0.0023	0.23948
Embodiment 2	0.0115	0.0021	0.18110	Comparative Examples 1	0.058	0.045	0.288
Comparative Examples 2	0.020	0.021	0.263	Comparative Examples 1	0.058	0.045	0.288

As can be seen from Table 2, by embodiment 1 and 2 preparations contain the rare earth one-ton brass, its corrosion resisting property all is better than common arsenic one-ton brass HSn70-1A and the HSn70-1B of containing.

The present invention is not limited to the foregoing description, when practical application, can select the different proportionings in the foregoing description according to the one-ton brass prolong in the different quality use occasion, or the different proportionings except that the various embodiments described above, but all do not limit the scope of the invention in any form.

Claims

1. tin-brass alloy containing rare earth, comprise copper, zinc is characterized in that also comprising simultaneously tin, aluminium, nickel, manganese, antimony, boron, with lanthanum, cerium lightweight rare earth element is main norium, and the composition of each component is respectively by weight percentage: copper 69～71%, tin 0.5～1%, aluminium 0.1～0.5%, nickel 0.1～0.5%, manganese 0.1～0.6%, antimony 0.01～0.05%, boron 0.002～0.02%, with lanthanum, cerium lightweight rare earth element is main norium 0.02～0.2%, and all the other are not more than 0.05% impurity for zinc and total amount, and the weight percent summation of each component is 100%.