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Pulverization Mechanism And Preparation Way Of The Silicon-manganese Alloy With Aluminum And Titanium

Posted on:2011-03-20Degree:MasterType:Thesis
Country:ChinaCandidate:Z W XieFull Text:PDF
GTID:2131330338982947Subject:Metallurgical engineering
Abstract/Summary:PDF Full Text Request
China (with manganese ore grade 15% 30%) is abound of the manganese resource. But, China's manganese industry has high cost, high energy consumption and low level products. So, China needs to reform the manganese industry to make full use of their manganese resource. According to the stated above as well as the present condition of China's steelmaking, the Al-Mn-Ti master alloy with high Mn-content was researched to add the cost of manganese products and improve the competitiveness of China's manganese industry.Al-Mn-Si-Ti series alloy is a new compound deoxidizing and alloying master alloy for converter steelmaking, which has high deoxidization efficiency, while can provide the required alloy elements, refine grains and improve the integrated using performance of steel. It is one of the main compound deoxidizing and alloying master alloy in the future. However, it is difficult to prevent pulverization and reduce burning loss rate in the alloy preparation. The pulverization of this kind of alloy and burning loss rate of aluminum which are key parts have been studied. The results are listed below.①To reduce the oxidation burning loss rate of aluminum, the smelting process is adding the bottom slag and a small amount of scrap aluminum debris firstly and then adding silicon-manganese and ferrotitanium alloy secondly, then adding quickly the remaining aluminum block until the formers completely melted, casting after completely melted as soon as possible to reduce the presence time of aluminum in the high temperature.②A series of measures, e.g. choosing the aluminum block of a = 30mm or d = 40mm, adding slag and cleaning, and drying the scrap aluminum debris are adopted to reduce the burning of aluminum.③The influence of Al, Mn and Ti content, the basicity of the slag on the pulverization of alloy are investigated. It found that Al and Ti content is disincentive for Pulverization as increasing, the increase of Mn content will promote the pulverization, and the alloy is most stable as basicity equals to 2.④The excessive speed of solidification caused the alloy solidification shrinkage, shrinkage and thermal cracks increasing had been discovered by macroscopic morphology analysis, it indicated a simple mold crucible could help to reduce the oxidation loss in solidification process, but would not conducive to the stability of macro-structure. So the directional solidification can be used to reduce alloy's casting defects.⑤The alloy phase has been analyzed by EDS, XRD. The results show that the alloy phase TiFeSi2,β-Mn, AlFe3 and TiC exist in alloy. The viewpoint about Al3C4, AlP hydrolysis in wet environment causes the pulverization of alloy has been negated by the existence of TiC phase. The theory that the interaction between Al2O3 phase and matrix phaseβ-Mn causes residual stress to lead the Pulverization of the alloy has been put forward in this paper.
Keywords/Search Tags:Al-Mn-Si-Ti alloy, Pulverization, Crack source, Burning loss
PDF Full Text Request
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