CN102002715B

CN102002715B - High-performance aluminium alloy sacrificial anode

Info

Publication number: CN102002715B
Application number: CN201010516697XA
Authority: CN
Inventors: 赵永韬
Original assignee: Qingdao Sunrui Marine Environment Engineering Co Ltd
Current assignee: Qingdao Sunrui Marine Environment Engineering Co Ltd
Priority date: 2010-10-12
Filing date: 2010-10-12
Publication date: 2012-06-27
Anticipated expiration: 2030-10-12
Also published as: CN102002715A

Abstract

The invention belongs to the technical field of corrosion and protection, and relates to a high-performance aluminium alloy sacrificial anode for protecting cathodes in equipment corrosion occasions under marine environment. Alloy elements such as Mg, Sn and Si are added on the basis of Al-Zn-In, so that the electrochemical performance of an anode is improved; and the preparation process for the aluminium alloy sacrificial anode is a fusion-cast process, which comprises the following steps of: heating and controlling the temperature to be 700-800DEG C in a heating furnace to make an aluminium ingot melted; respectively weighing five elements of Zn, In, Mg, Si and Sn according to a formula ratio; respectively adding five elements into the molten aluminium sequentially, stirring uniformly by using a graphite rod, and deslagging; and casting the alloy melt into a mold, cooling and taking out the anode. The preparation process is simple; the element components are readily available, the cost is low, the electrochemical performance of the product is good, and the electric capacity is more than or equal to 2,700Ah/kg and the current efficiency is more than or equal to 92 percent under the seawater full immersion environment.

Description

A kind of high-performance aluminium alloy sacrificial anode

Technical field:

The invention belongs to the corrosion and protection technical field, relate in a kind of ocean environment the galvanic protection under the equipment corrosion occasion and use the high-performance aluminium alloy sacrificial anode.

Background technology:

Aluminium is self-passivating metal, no matter is aluminium or duraluminum, and the surface is very easily passivation all; If exploitation aluminium is made sacrificial anode material; Can only and stop the surface to form the continuity sull through the alloying restriction, promote surface active, make alloy have negative current potential and higher current efficiency.The prior art situation is added zinc, cadmium, magnesium and barium separately in aluminium, can make the current potential of aluminium become negative 0.1～0.3V; Add the negative 0.3～0.9V of current potential change that element very small amount such as mercury, indium, gallium just can make aluminium separately; Add separately these elements and also can make the current potential of duraluminum reach requirement, but current efficiency is lower, and prolong in time and descend.For improving the chemical property of duraluminum; Can make enough the bearing of current potential can make current efficiency higher again; Usually on the binary alloy basis, develop ternary alloy, quad alloy; Present established series comprises Al-Zn-Hg system, Al-Zn-In system, Al-Zn-Sn system, Al-Zn-Cd system and Al-Zn-Mg system etc., and wherein preceding two kinds of alloy series are that exploitation is early used more widely in the aluminum anode kind.Like Al-Zn-Hg is that the representative of alloy is the Galvalum I type and the II type aluminum anode of DOW chemical company exploitation; Its actual capacitance is very high, and current efficiency can reach 95%, but owing to mercury pollutes the environment; The mercury vapour that when melting, produces is harmful, so almost be eliminated at present; Al-Zn-In is that alloy is the promising aluminum anode series of generally acknowledging at present, and listed four kinds of anode compositions all belong to this series among the GB4948, and this serial basic ingredient is Al-2.5Zn-0.02In, and its current potential is at-1.10V (SCE), and current efficiency is about 85%; During work, the surface produces the gelationus corrosion product of one deck, and is comparatively soft, be prone to washed out by water, but etch state is even inadequately, and pit and blister are arranged; In order further to improve anode performance, both at home and abroad the investigator in Al-Zn-In, added the 4th again, the 5th kind of element; For example, the Galvalum III of U.S. DOW chemical company exploitation in 1976 is a typical representative, and its composition is Al-3Zn-0.015In-0.1Si, and its electrochemistry capacitance in seawater is generally about 2550A-h/kg; Stipulated among the Chinese Industrial Standards (CIS) GB/T 4948-2002 that five kinds of Al-Zn-In are alloy anode; Wherein Al-Zn-In-Cd, Al-Zn-In-Sn, Al-Zn-In-Si and four kinds of anode actual capacitances of Al-Zn-In-Sn-Mg are usually about 2500A-h/kg, and the actual capacitance of Al-Zn-In-Mg-Ti is about 2600A-h/kg; The Al-Zn-In that the standard DNVRP B401 of Veritas recommends is an alloy anode, and actual capacitance is usually also only about 2500A-h/kg.End is got up; It is complicated that existing sacrificial aluminium alloy anode ubiquity constituent structure; Chemical property is not enough, and electrical capacity is not high, and price is unreasonable; Should not be in shortcomings such as briny environment uses, and the hexa-atomic sacrificial aluminium alloy anode of novel high-performance Al-Zn-In-Mg-Si-Sn does not also appear in the newspapers at present as yet.

Summary of the invention:

The objective of the invention is to overcome the shortcoming that prior art exists, seek to adopt conventional a kind of novel high-performance aluminium alloy sacrificial anode material of fusion casting design preparation, this anode material can use in briny environment, extensively improves its chemical property.

To achieve these goals; The present invention has added alloying element Mg, Sn, Si on the basis of Al-Zn-In; Eliminate the disadvantageous effect of impurity element through the alloying of element; Improve the anode electrochemical performance, make the electrical capacity of anode in briny environment reach 2700Ah/kg～2800Ah/kg, electric capacity has significantly raising; Through interpolation alloying element Mg, Si, Sn on the basis of Al-Zn-In, and control the part by weight between Al, Zn, In, Mg, Si, six kinds of alloying elements of Sn, realize the raising of anode electrochemical performance; The weight percent prescription of its six kinds of alloying elements is: Zn:1.0-3.0%; In:0.015-0.025%; Mg:1.5-4.0%; Si:0.05-0.7%; Sn:0.002-0.015%; Foreign matter content: Fe≤0.15%; Cu≤0.01%; Surplus is Al, and the ratio of Al is 92.260-97.433%.

The preparation technology of the sacrificial aluminium alloy anode that the present invention relates to is a fusion casting; Earlier heating temperature control to 700～800 ℃ make the aluminium ingot fusing in process furnace; According to prescription than calculating respectively and weighing Zn, In, Mg, Si, five kinds of elements of Sn, again in molten aluminum liquid respectively order add five kinds of elements, and remove the gred with the graphite rod back that stirs; Then the alloy liquation is cast in the anodic mould, the cooling back is taken out anode and is product.

The present invention compared with prior art, its preparation technology is simple, elementary composition is easy to get, cost is low, the chemical property of product is good, the open circuit potential that wherein in seawater, soaks entirely under the environment is-1.18～-1.10; Operating potential is-1.12～-1.05; Electrical capacity >=2700Ah/kg; Current efficiency >=92%, product comes off easily, and surface dissolution is even.

Embodiment:

Through embodiment the present invention is further specified below.

Embodiment 1:

The weight percent prescription of the sacrificial aluminium alloy anode of present embodiment is: Zn:3.000%; In:0.020%; Mg:1.500%; Si:0.190%; Sn:0.006%; Foreign matter content: Fe:0.060%; Cu:0.005%; Surplus Al is 95.219%; Heating temperature control to 700～800 ℃ make the aluminium ingot fusing in process furnace; Compare calculating respectively and weighing Zn, In, Mg, Si, five kinds of elements of Sn according to filling a prescription; In molten aluminum liquid, add five kinds of elements respectively, stir, slagging-off with graphite rod; Be cast to then in the anodic mould, the cooling back is taken out anode and is product.

Embodiment 2:

The weight percent prescription of the sacrificial aluminium alloy anode of present embodiment is: Zn:1.500%; In:0.015%; Mg:2.000%; Si:0.200%; Sn:0.009%; Foreign matter content: Fe:0.090%; Cu:0.004%; Surplus Al is 96.182%; Heating temperature control to 700～800 ℃ make the aluminium ingot fusing in process furnace; Compare calculating respectively and weighing Zn, In, Mg, Si, five kinds of elements of Sn according to filling a prescription; In molten aluminum liquid, add five kinds of elements respectively, stir, slagging-off with graphite rod; Be cast to then in the anodic mould, the cooling back is taken out anode and is product.

Embodiment 3:

The weight percent prescription of the sacrificial aluminium alloy anode of present embodiment is: Zn:2.400%; In:0.025%; Mg:2.200%; Si:0.080%; Sn:0.015%; Foreign matter content: Fe:0.095%; Cu:0.005%; Surplus Al is 95.180%; Heating temperature control to 700～800 ℃ make the aluminium ingot fusing in process furnace; Compare calculating respectively and weighing Zn, In, Mg, Si, five kinds of elements of Sn according to filling a prescription; In molten aluminum liquid, add five kinds of elements respectively, stir, slagging-off with graphite rod; Be cast to then in the anodic mould, the cooling back is taken out anode and is product.

Present embodiment is according to general national standard, and promptly GB/T 17848-1999 specified standards TP is tested its result such as table 1 to the chemical property of the aluminium alloy sacrificial anode material of the present invention's preparation.

Table 1: the chemical property of the sacrificial aluminium alloy anode of present embodiment

The novel high-performance sacrificial aluminium alloy anode of the chemical property value explanation the present invention preparation in the table 1 is superior to prior art products, and it is identical in the result of use of soaking entirely under the briny environment.

Claims

1. a high-performance aluminium alloy sacrificial anode is characterized in that on the basis of Al-Zn-In, adding alloying element Mg, Si, Sn, realizes the raising of anode electrochemical performance; The weight percent prescription of six kinds of alloying elements is: Zn:1.0-3.0%; In:0.015-0.025%; Mg:1.5-4.0%; Si:0.05-0.7%; Sn:0.002-0.015%; Al is 92.260-97.433%; Foreign matter content: Fe≤0.15%; Cu≤0.01%.

2. high-performance aluminium alloy sacrificial anode according to claim 1; The preparation technology of the sacrificial aluminium alloy anode that it is characterized in that relating to is a fusion casting, and heating temperature control to 700～800 ℃ make the aluminium ingot fusing in process furnace earlier, according to prescription than calculating respectively and weighing Zn, In, Mg, Si, five kinds of elements of Sn; In molten aluminum liquid, add five kinds of elements more respectively in proper order; And with stir back slagging-off of graphite rod, then the alloy liquation is cast in the mould, the cooling back is taken out anode and is product.