Papers by Author: Shu Huan Wang

Abstract: We studied the nitrogen macrosegregation of the HNS, and found that there were severe vertical segregation and horizontal segregation. Both of them are normal segregation. The study shown that the overflow area of nitrogen bubbles in the process of solidification is due to the nitrogen macrosegregation.

Abstract: The indirect coupled modeling of the metal base disrepair has been carried out by software ANSYS. Results show that diagonal tensile stress is the main factor of crack, crack easily take place in the lower surface, where obviously exist a region of stress concentration in 45°direction. It should make symmetrical and uniform distribution as much as possible

Abstract: The method of smelting High nitrogen steels by blowing nitrogen from the device bottom is a promising way of increasing nitrogen with gas. Introduced the device and technical development of smelting High nitrogen steels in domestic and foreign countries, expounded the method and character of dissolving nitrogen into liquid steel at high temperature and high pressure, and analyzed the advantage of increasing nitrogen by bottom-blowing nitrogen. The domestic research is at the developing period of experimental research. The High nitrogen steels which content is more than 1.0% was produced with bottom-blowing nitrogen method at high pressure. The velocity of dissolving nitrogen with bottom-blowing was increased and the smelting time was shortened. The technical effect was very good.

Abstract: Based on the phase diagrams analysis, the activity model of Fe-C-B ternary system was established with the ion and molecule coexistence theory. The activities of Fe, C, B, Fe3C, FeB, FeB2 and B4C in melt were calculated by analyzing the model. We have researched the thermodynamic condition of boron oxide reducing with carbothermic method and analyzed the effects of CO partial pressure, B2O3 content and slag type for the lowest smelting temperature. In normal pressure, the carbon content is high in melt, so it needs 2000°C for decarbonizing and chrome remaining. When CO partial pressure is 0.1 kPa and CaO content is less 60%, the lowest temperature of smelting ferro boron could be below 1600°C.

Abstract: In the paper, the reaction of solid-solid model was researched and we confirmed the reaction equation. The experiments in the lab shown that the t1/2 is 11.8min in the ferrosilicon reduction boron anhydride reaction at low temperature. The yield of boron is higher by direct reduction method smelting. In the boron oxide reducing experiment, the yield minimum is 76%, the maximum is 82%, and the average value is about 79%, which provides favorable foundation conditions for smelting amorphous mother alloy.

Abstract: Analyzed the reaction between slag and liquid iron and done a lot of experiments in the Lab to find the effect of many factors. It shown that putting into CaO to low the reaction activity with small amount of calcium oxide added, it can make the expansion in reaction to be inhibited, and improve the content of CaO in further. Silicate is high melting point material in the reaction product. After the reaction it reduce the slag fluidity to the slag with addition of CaF2, which can further improve the effect of reduction reaction.

Abstract: Researched on the refractory material corrosion by experiments. Each refractory was measured to take four different parts, and the average corrosion thicknesses of silicon carbide, quartz and corundum were 0.52mm, 1.03mm and 1.40mm. The corrosion of corundum refractory was most serious, and quartz refractory had a certain degree of corrosion, but it was not very serious. The corrosion of silicon carbide refractory was the least. In the experiment in intermediate frequency furnace, only upper and lower parts of slag line were connected to the refractory and the degree of corrosion was little for silicon carbide crucible. Slag part of the wall thickness was about 16.6mm after the reaction. Amorphous master alloy parts of the wall thicknessis about 16.9mm. For quartz crucible, refractory corrosion was much bigger, which was 10 mm thick before reaction. The erosion thick was about 2~3mm. It was a little thicker than corrosion experiment in static crucible.

Abstract: The mechanism of refractory material corrosion was analyzed. The laboratory amorphous alloy smelting of the mother prefabricated crucible, reaction process is basically to crucible refractory material of blast furnace slag corrosion, melt corrosion is small. Generally smelting amorphous mother alloy was a difficult thing, and it shown that the basicity was better around 1.0. Compared with quartz refractory, it is good to choose the silicon carbide refractory materials, while smelting amorphous alloy.

Abstract: The largest proportion of element in master alloys were iron and pure iron smelting industrial used accounts for 70% of the total raw materials. Iron produced by secondary refining has the highest purity. If the inclusion in the raw materials is very low, inclusions in smelting amorphous master alloy would be lower. The carbon content of 0.1% in the carbon-75 ferrosilicon, but ferrosilicon dosage is small, generally is about 10%, so the carbon content in the master alloy is below 0.01%. Boron anhydride generally containing boron oxide at about 95%, the rest is mainly water, contains less impurities, the alumina content is generally below 0.1%, as well as chloride, which have little effect on master alloy smelting. Impurities in additive calcium oxide, calcium fluoride are generally below 10%, mainly are oxides, presenting in the slag in the smelting master alloys basically.

Abstract: The thermodynamic analysis shown that oxygen content in master alloy is very low, so other alloy elements content which are balance to oxygen are relatively high. In the amorphous master alloy, deoxidizing capacity of silicon is stronger than boron, and with process of decrease of the temperature, oxygen content decrease. The silicon in the master alloy can also take off the oxygen content below 1 ppm. Denitrification capacity of boron is stronger than silicon, and with process of decrease of the temperature, nitrogen content decrease. The boron in the master alloy can also take off the nitrogen content below 4 ppm. All of the research are based on energy materials and it will be useful for the development for energy saving.