Microstructures and Corrosion Resistance of Al2O3—C Based Refractories to the Melts Containing Titania

The corrosion resisance of the Al2O3-C based refrac-tories in melts containing titania has been studied by quasi-station immersion and rotary immersionThe corrosion rate is decreased with the addition of graphite carbon and ZrO2 in the refractories.The corrosion mehanism of Al2O3-C refractories is the oxidization of graphite carbon by the oxides of the melts and the formation of deteriorate layer,For the Al2O3-C-ZrO2 refractories,the corrosion behavior is due to the interaction between melts and refrac-tories,The new compounds of FeO.SiO2,SiZrO4,Feo.3CaO,2CaO.SiO2 and CaO.SiO2 are formed in the deteriorate layer.     

还原冶炼时高铝石墨质耐火材料对熔体的抗侵蚀性

采用静止的方法及动力学方法研究了Al2O3-C质耐火材料在还原冶炼的熔体中的抗侵蚀性。研究了试验后试样的微观结构。查明,当向刚玉石墨质耐火材料中加入碳（以石墨形成加入）及ZrO2时其抗侵蚀性将随之降低。试验结果表明,含ZrO2的砖的抗侵蚀性高于不含ZrO2的砖。加入ZrO2时有助于提高耐火材料的抗氧化性,井使熔体和耐火材料之间的反应速度下降。Al2O3-C质耐火材料受到侵蚀的原因,一是熔体和耐火材料之间发生反应,二是耐火材料的组分在熔体中发生分解所致。     

Corrosion Resistance and Microstructure of High-Alumina Refractories, Based on the Rotary Slag Test

The corrosion resistance and microstructure of four highalumina and two chromia-containing high-alumina refractories were evaluated. Analysis of the refractories after exposure in the rotary slag test showed that the chromia-containing products had better slag resistance than the chromia-free products. Three factors contributed to this conclusion, including formation of a Cr-spinel layer at the slag/refractory interface, formation of an impermeable mullite layer just below the interface, and improved matrix bonding from chromia-alumina solid-solution formation.     

Corrosion Resistance Mechanism of MgO-CaO Refractories to Refining Slag

Corrosion resistance and penetration resistance of MgO-CaO materials with different CaO contents （22%, 42%, 49%, 53%, in mass）to refining AOD slag or VOD slag were investigated using static crucible technique by visual observation, SEM and XRD. The corrosion resistance and penetration resistance of speci-mens decrease with the increase of CaO content. This may be caused by the formation of C3S and C2S during the reactions between specimens and the slag. The formed C3S and C2S can restrain the further penetration to the matrix. The higher the CaO content, the more the C2S or C3S formed, the lower the porosity of the speci-mens, and the lower the penetration depth and corrosion rate. The corrosion resistance to AOD slag is better than that to VOD slag, because the reaction between AOD slag and the matrix is slighter than that between VOD slag and the matrix.     

含钒渣对铝碳材料的侵蚀

为了探讨含矾渣对铝碳材料的侵蚀机制,用动态感应抗渣法研究了w(V2O5)=10%、碱度2.8,w(V2O5)=6%、碱度2.8,w(V2O5)=6%、碱度1.44的3种含钒渣对铝碳材料的侵蚀。结果表明:随着V2O5含量(w)由6%增加到10%,铝碳材料的熔损指数增加;随着碱度的增加,铝碳材料的熔损指数也增加;添加电熔镁砂有助于提高铝碳材料的抗侵蚀性能。显微分析表明:V、Ti元素渗透能力强,渗透深,而尖晶石可固溶少量V2O5、MnO及FeO。     

Effect of ZrO_2-nitrides Composite Powder Addition on Oxidation Resistance of Al_2O_3-C Refractories

Oxidation of carbon is the main problem of Al2O3-C refractories.ZrO2-nitrides composite powder was synthesized through carbothermal reduction and nitridation (CRN) of zircon.The effect of ZrO2-nitrides composite powder addition on oxidation resistance of the Al2O3-C refractories was investigated by measuring the thickness of oxidation layer.Phase compositions of the Al2O3-C refractories before and after oxidation were investigated by X-ray diffraction (XRD).Results show that the oxidation resistance of the ...     

Corrosion resistance of AlN-based ceramics to molten uranium

A kind of AlN-based ceramics was prepared as a lining material of the high-density graphite crucible for high temperature melting uranium. During the corrosion experiment, the corrosion rate showed a downward trend with the increase of corrosion time. As the corrosion time increased from 2 h to 8 h, the corrosion rate showed a gradual downward trend from 0.25 mg cm^?2 h^?1 to 0.22 mg cm^?2 h^?1, and then decreased significantly to 0.07 mg cm^?2 h^?1 at 16 h. A dense layer consisting of UO₂, Y₂O₃ and UC was formed between molten uranium and AlN-based ceramics, and the thickness increased with the extension of corrosion time, resulting in a significant decrease in corrosion rate.     

Slag Corrosion Resistance of MgO-ZrO2 Refractories

Slag corrosion resistance of MgO ZrO2 refractories was investigated in this work. The results indicate that in a non-oriented electric steel slag system with a high ratio of calcia to silica,the slag resistance of MgO ZrO2 refractories can be described as follows: ZrO2 reacts with CaO forming calcium zirconate compound which strengthens the material and blocks the channel of the slag infiltration; however,in an oriented electric steel slag system with a high concentration of silica and the low ratio of calcia to silica,the slag corrosion resistance of MgO ZrO2 refractories is different; ZrO2 reacts with CaO forming the calcium zirconate and simultaneously one more product C2S as well; C2S can improve corrosion resistance by blinding pore and enhancing slag viscosity; therefore,it is expected to be the major reason for the enhanced corrosion resistance observed for MgO ZrO2 refractories.     

Al2O3-ZrN-Sialon-C复相耐火材料抗渣侵性能研究

以板状刚玉、石墨、α-Al2O3、金属铝粉、单质硅粉为主要原料,ZrN-Sialon复相粉体为添加剂,采用酚醛树脂结合制备了Al2O3-ZrN-Sialon-C复相耐火材料.采用静态坩埚法研究了ZrN-Sialon复相粉体加入量对材料抗渣侵蚀性能的影响,借助SEM与EDS面扫描对渣蚀后材料的结构和成份进行分析,并探讨了Al2O3-ZrN-Sialon-C复相耐火材料的抗渣侵蚀机理.结果表明:ZrN-Sialon复相粉体加入量为9wt％时,材料表现突出的抗钢渣侵蚀性能.研究表明材料中Sialon氧化后生成的SiO2能形成致密的氧化保护层,同时ZrN氧化后形成的ZrO2有利于提高抗钢渣的浸润,阻止钢渣的渗透与侵蚀.分析认为Al2O3-ZrN-Sialon-C复相耐火材料的钢渣侵蚀机理为氧化-熔蚀-渗透.     

镁锆砖的抗侵蚀性能研究

采用两种不同炉渣,用静态坩埚法对镁锆砖的抗侵蚀性能进行了研究,并通过SEM和XRD等分析手段对镁锆砖的侵蚀机理进行了探索。结果表明：两种炉渣对镁锆砖的侵蚀情况略有不同;抗渣试验过程中未发生ZrO2的晶相转变。镁锆砖的侵蚀机理为：渣中的CaO与砖中的ZrO2发生反应生成高熔点物相CaZrO3,CaZrO3的生成在方镁石晶间形成了致密保护层,从而阻止了渣对镁锆砖的继续侵蚀。     

微孔镁尖晶石碳耐火材料的抗渣性能研究

以方镁石-尖晶石微孔陶瓷、电熔镁砂为骨料,以电熔镁砂细粉、鳞片石墨、金属铝粉为基质材料,以酚醛树脂为结合剂制备了含微孔陶瓷骨料的镁尖晶石碳试样.采用感应炉浸渍法对试样进行了抗渣试验,并对渣蚀后的试样进行了SEM和EDAX分析.结果发现:熔渣和熔钢冲刷是损毁的主要原因,熔损并不显著.显微结构分析表明,在侵蚀层和原质层之间可以发现MgO致密层的形成,MgO致密层的形成可抑制渣对试样进一步的侵蚀和渗透.渣对MSO颗粒的侵蚀主要是FeO和MnO等在方镁石中的固溶,导致MgO颗粒出现结构剥落;方镁石-尖晶石微孔陶瓷骨料的蚀损主要是尖晶石被渣中的CaO和SiO2所侵蚀,而渣对微孔骨料渗透并不严重.     

镀锡板耐蚀性研究及进展

综述了镀锡原板、前处理、电镀、软熔以及钝化工艺等对镀锡板耐蚀性的影响，并展望了镀锡板的发展趋势。     

高速镀锌工艺对镀层耐蚀性的影响

通过湿热实验,塔菲尔曲线的测量和中性盐雾实验研究了高速镀工艺对镀层耐蚀性的影响,实验采用明度差来表征镀层的初期腐蚀速率,结果表明,随着电流密度和ZnSO4.7H2O浓度的增加,镀层的耐初期腐蚀变色性和耐蚀性增强,同时还发现高速镀锌过程中的电流效率和镀层耐蚀性成一定的正比关系。     

Effect of Metallic Zn Powder on Oxidation Resistance of Al2O3 -C Refractories

1 IntroductionCharacterized by excellent thermal shock resist-ance, slag erosion resistance, Al2O3-C refractory hasalready been widely used as some functional parts forcontinuous casting system, such as slide plate, nozzleand so on. However, during the ap…     

R60702管板角接接头耐蚀性研究

工业纯锆R60702是一种稀有金属,具有良好的焊接性和抗腐蚀性,其熔点、硬度和强度均很高。分析了R60702在经过管板角接后,焊缝的元素成分和耐腐蚀性能,通过极化曲线和交流阻抗图分别表征了锆材焊缝在30℃和70℃的耐蚀性。     

Improvement on Corrosion Resistance of Zirconia-Graphite Material for Powder Line of SEN

The influence of anti-oxidation additions and microstructure characters of fused zirconia raw materials on the corrosion resistance of ZrO2-C were studied.The results show that BN addition can enhance the corrosion resistance of ZrO2-C due to the prevention of graphite oxidation,and zirconia raw material with good crystallization and densification will give better corrosion resistance by restrain the reaction between slag and zirconia.     

Ni-纳米SiO2复合镀层耐蚀性的初探

制备了纳米氧化硅—镍复合镀层材料，并利用静态浸泡法对纯镍镀层和由镀液中不同微粒含量制备的复合镀层耐蚀性能进行研究，讨论了镀液中纳米微粒含量对镀层抗蚀性的影响，并用扫描电镜观察镀层的表面形貌。