Study on Corrosion Mechanism of Aluminium Liquid in Iron Base Alloy

Analysis; combined with iron-aluminum phase and experimental results. The corrosion process of iron-based alloy aluminum liquid is discussed.

The Sino-French classification number 174.3, cited hundreds of strokes and aluminum alloys have been used in a large number of industries, and their smelting, processing, casting and other processes are inevitably in contact with steel materials. For example, in the smelting process, the molten aluminum liquid will cause corrosion and damage to the molten aluminum container. Iron and aluminum will generate mutual diffusion at high temperatures. Iron atoms diffuse into the aluminum liquid through the interface and become impurities, thereby reducing the purity of the aluminum liquid. As a result, the quality of the wrong alloy part is affected. In the casting process, the molten liquid that you melt will form aluminum bumps on the surface of the casting cast. In this respect, the surface precision of the aluminum alloy molded part is reduced; on the other hand, the life of the die casting is affected. 1.

The mutual etching process of aluminum liquid and iron-base material under high temperature conditions and the mechanism of aluminum liquid corrosion are studied. Based on this, feasible protective measures are proposed, which can effectively solve the diffusion of iron atoms into the wrong solution and affect aluminum. Liquid purity, corrosive perforation of miscible containers, and sticky aluminum of aluminum profile molds, etc. To solve these problems, it is practically necessary to effectively improve the quality and efficiency of production, increase the use of containers and molds, and reduce the number of garments and increase economic efficiency.

The Etching Mechanism of Iron Base Alloy in Molten Aluminum Liquid and How to Solve It . The iron-niobium alloys have attracted much attention for their resistance to bumping. A test program soaked the iron-based alloy specimens in a molten aluminum bath of 740°C for a fixed time, and then removed them to form a metallographic specimen, which was divided by scanning electron microscopy. Pray for corrosion of the organization, with the ability to pinpoint the determination of the phase of the wood. In the experiment, graphite crucibles were used for stacking, 2,01-person liquid Fengle was used for liquid injection, and 45 steels were used for iron-based alloys. According to the national standard, 8102148 concentrated metal materials were uniformly etched in the laboratory and the test was conducted in a circular test. kind. Dimensions are 2,3025. The sample is cut radially from the rolled 45-round steel and cut along the cross-section. The grinding machine grinds while it is divided into 6 groups of 2 each. After the sample was deoiled and the plating solution was treated, it was placed in a 740, and the etching experiment was performed in the molten aluminum. Every other time! Two samples were taken out and numbered separately. After rough grinding and etching, a metallographic sample was made. The corrosion-generated phase was observed under a scanning electron microscope, and the composition of the resulting phase was measured with an energy spectrometer.

2 experimental results analysis of iron and aluminum phase 1.

As known from the first phase, atoms are present in iron in different forms depending on the amount of aluminum and the effect of warm service. It is now in the form of a solid solution and an intermetallic compound. This includes the formation of a solid 1 with aluminum as the solute 1; the solid solution is abbreviated as 1 61. The force phase is present only in the low temperature state of 50; 1 in 1; 1715, and 13 in the aluminum temperature of 7401 aluminum. The maximum solubility in 13 Ã… was in the range of 14.2 guan 34.1, 18.1 double 14.2, and 15-phase biphasic coexistence. 20 is in the form of an intermetallic compound, in which person 1 has a defined range of existence but does not change with temperature. The existence range of the phase is 44.8 polar phase in the range of 521æµ¼54.7 credits, and the target exists in the range of 58.2 and 63.2 articles.

1! Metallographic photos.

Calls, 5740, 4 Corrosion 25D2 Center 8, jurisdiction 鸹, 澹, 赡芷滓 Send, get 00 people 1 content 47.8 View 56.2 purchase, combined with iron 钔 phase known, on; The alloy phase, 1's, 1's content is 68.8 at 75.7, which is mainly based on the iron-aluminum alloy phase. In 3, iron bases began to be eroded gradually, and in 4 the appearance of broken points in the generated 2 phases can be clearly seen. 5, Long time 1 contains the most 16 fees, point 1 content is 53.47, 1 point content is 94.5 private.

At the molten aluminum temperature, the phenomenon of infiltration first occurs, then the chemical adsorption of the wrong atoms and the chemical reaction, the reaction begins, the phase, its. The iron-aluminum compound in the upper part has the lowest heat of formation and then the iron helium atoms change by diffusion from the molecules in the interaction helium, due to the uniformity of the human 131. Some places are rich in iron and aluminum, and some are rich in aluminum. During the phase change process, some local enterprises are transformed into zero, and some are partially transformed into 0+2. The dual effects of the transformation stress and the thermal diffusion stress cause partial exfoliation of the brittle 2 phase. Luo Jie, the history of the stomach in the aluminum liquid is re-exposed to the molten aluminum environment by re-exposure to a partially fresh iron matrix, causing corrosion to occur quickly in some areas. Ruthenium has a slower corrosion. Macroscopic clothing is now corroded by 5 sample surface roughness +7.

According to the above test results, the iron-based alloy aluminum liquid corrosion process 8.

When the solid iron base contacts the molten aluminum liquid, mutual diffusion occurs at the interface. This results in an intrinsic phase with the least iron content in each matrix, and a zero-phase phase in the iron-based diffusion layer. This is because the 9 phase generates heat only in the entire iron-aluminum compound with only the second corpse 2 phases 2 and 5, and it is easy to satisfy the structural and compositional conditions required for the phase transition. The human 13 is a monoclinic crystal structure, containing 1 human being 52 is now 63.2 Material, 32 people 15 is an orthorhombic structure, containing 1 521 æµ¼ 54.73, 2. After 9 phases are formed, the interdiffusion of iron atoms and aluminum atoms is carried out under the condition of passing through phase 0. At this time, diffusion occurs. Occupy a secondary position. The interdiffusion of 9-phase and iron causes the phase composition of the diffusion layer to change, and the 9-phase begins to partially change to 2 phases. Due to the fact that the aluminum atoms are diffused along the two-phase axis, the axis is most rapidly diffused, so that the two phases have a parallel stripe structure. This large structure of the tongue is loose, brittle, and easily peels off and dissolves. Because the two-phase structure is not the same, there is a tissue transformation stress; in addition, there will be thermal stress in the temperature fluctuation fluctuations. Under the dual effects of this tissue transformation stress and thermal stress, the two phases will be partially exfoliated and dissolved first. After the two phases peeled off, they will be exposed fresh and new, forming 9 phase 8 such as the Court, the original did not, the broken lake will continue to grow, will eventually break and dissolve in the liquid aluminum, and in the new iron matrix 1 to generate 9 phase, Previously generated, the meeting gradually changed to 2-8, so erosion continues.

3 Conclusion 1 The iron-based alloy aluminum liquid corrosion mechanism is that at high temperature conditions, iron and aluminum atoms interdiffuse and form ferrous aluminum alloy layer, iron and aluminum alloy layer changes in organization, under the influence of the tissue transformation stress and thermal stress, to the Brittle fractures and dissolves, leading to gradual erosion of iron-based alloys.

The way to resist the corrosion of aluminum liquid is to delay the reaction of iron or tile under high temperature conditions, or to prevent the iron and aluminum from contacting each other under high temperature conditions. From the delayed angle of service, feasible solutions include thermal diffusion, such as chemical boronization and chemical chromizing; from the standpoint of prevention, a feasible solution is to spray ceramic layers.

1 Frozen peacekeeping. Zhu Shangzhong. The goods let students wait. Study of Brand New Aluminum Alloy Cast Iron. Journal of Hulan University. 1991.1814776 Liquid aluminum silicon alloy etched mortar. Corrosion and Protection, Jian Guangjian Wang Xiaojing became an adjunct professor at our school Recently, the school presented the appointment ceremony for Ding Guangjian and Wang Xiaojing as part-time professors. He was appointed Senior Researcher Lubricating Engineer, Ding Guangjian, Institute of Highway Research, Ministry of Transport, Australia. Deputy Director Wang Xiaojing, deputy director, is an adjunct professor at our school.

Mr. Guangjian Guang mainly engages in the research and improvement of decision-making and implementation of the improvement of lubrication oil maintenance technology of large-scale companies, as well as the research and training of training courses and plans for industrial companies. Researcher Wang Xiaojing has long been engaged in the development of smart transportation systems, national intelligent traffic standards, national intelligent transportation system framework, and other aspects. The two professors have achieved fruitful results in their respective research fields. At the appointment ceremony, Vice President Yan Xinping read out the appointment decision and issued a letter of appointment on behalf of the school.

Reporter Zhu Kui