连铸中间包绝热板用粘合剂研制

本文叙述了连铸中间包绝热板粘合剂的合成方法，对其填充料的选择一无是处地较细致分析，产品用于连铸中间包绝热板后，取得了较理想的效果并已获得较好的经济和社会。效益     

冷中间包衬对铸坯皮下气泡的影响

对铸坯产生皮下气泡的原因进行了调查和分析。认为中间包绝热板村中的有机挥发物和残余水分是铸坯产生皮下气泡的主要原因。从中间包绝热板的配方、制造技术和装砌等方面采取改进措施，可有效减少铸坯皮下气泡。     

天然镁质纤维对中间包涂料性能的影响

连铸中间包涂料经历了绝热板、湿法涂料、干式振动料等不同历程。其中绝热板使用寿命在 8～ 10h ,使用寿命短 ,施工劳动强度大 ,须处理渣量较大 ;干式振动料使用寿命一般在 3 0h以上 ,涂层易解体 ,成本较高 ,但施工周期较长 ;湿法涂料介于二者之间 ,其使用寿命一般在 16～ 2 4h ,施工较容易。从连铸生产成本考虑 ,若连铸工艺能保证连续 3 0h以上正常生产的 ,则应首选干式振动料 ,因为尽管干式振动料的单包原材料成本较高 ,但单包拉坯量大幅度提高 ,其单位拉坯量的生产成本反而比湿法涂抹料低 ;若连续拉坯统计时间在 10～ 2 4h之间 ,使用湿法…     

镁质干式料在薄板坯连铸中间包上的应用

中间包工作层直接与钢水接触 ,要求中间包工作层能减少钢液中的夹杂物 ,提高钢的纯净度 ,而且耐钢水和熔渣的侵蚀性能好 ,以使薄板坯连铸浇钢时间尽可能长 ,用后易解体 ,以减小劳动强度。中间包工作层近年的发展趋势表现在两个方面 :( 1)形式上由绝热板发展为喷涂料、干式料 ;( 2 )材质上发展为镁质、镁钙质等 ,起到净化钢水的作用。上世纪 90年代末 ,国外有了中间包干式料的报道。我厂结合现在喷涂料的使用情况 ,与北京某公司进行了干式料的试用 ,从实际使用效果看 ,好于原喷涂料 ,可以满足长时间浇注的需要。1　中间包干式料的优越性和理…     

中间包绝热板的损毁机理

研究了三种用后中间包绝热板的显微结构。其损毁机理为：硅质绝热板原石英颗粒向α－方石英转变，与渣反应生成大量玻璃相，属溶蚀型损毁；镁质绝热板与渣反应生成ＭＡ、Ｃ３ＭＳ２及黄长石类矿物．属溶蚀及剥落型损毁；镁橄榄石质绝热板与渣反应，原镁铁橄榄石固溶体中的［Ｆｅ］被渣相中的［Ｍｎ］置换反应生成镁锰铁橄榄石固溶体，析出［Ｆｅ］，属剥落及溶蚀型损毁。并讨论了绝热板对钢液质量的影响。     

长寿命定径水口的使用试验

定径水口是小方坯连铸用关键耐火材料之一,其品质的好坏直接影响连浇时间的长短.氧化锆定径水口抗冲刷、耐侵蚀、热震稳定性好,在我厂使用时其侵蚀速率为0.03～0.08 mm@H-1,年平均连浇时间达到了460min.1999年下半年,我厂方坯中间包开始采用镁质喷涂料取代硅质绝热板,中间包包衬的使用寿命明显提高,原有的普通氧化锆定径水口已不能满足使用要求.为此,研制开发了长寿命定径水口.     

板坯连铸中间包长寿技术实践

提高板坯连铸机中间包的寿命,对降低连铸用耐火材料消耗,减少中间包注余及铸坯切头、去尾,提高铸坯合格率等,都具有重要意义.目前,国内板坯连铸中间包的寿命较低,一般为12～16 h.为此,莱钢通过技术开发,解决了制约板坯连铸中间包寿命的几个关键技术难题,使中间包单包连浇时间由16 h提高到24 h以上.     

高性能镁质涂料的研制与应用

随着连铸中间包水口快速更换技术的推广应用,连浇炉数越来越高.如何提高中间包工作层耐火材料的使用寿命,实现真正意义上的连铸,已成为一个急待解决的课题.为此,研制了高性能镁质中间包涂料. 1 研制过程     

连铸中间包用耐火材料的改进

实践证明，非金属夹杂相当一部分是由耐火材料带来的，它不但影响钢的质量，也是制约中间包耐火材料寿命的重要一环。本文就安钢在这方面存在的问题进行分析，并提出了今后的改进措施。1现状和问题连铸采用罗可普LOKP120×120机组，用5台分别为4～8t的中间包、L6板坯弧形连铸机，用2台10t的中间包。冶金部要求第二炼钢厂实现全连铸，这些年来，二炼钢由经验炼钢向科学炼钢迈进，每炉钢的冶炼时间由27min45s缩短到ZOmin左右，板坯连铸的平均连拉次数达到40炉左右。近年来，第一、二炼钢厂改造和增设了煤气烤包设施，公司对钢包耐火材料寿…     

雀点厂连铸中间包采用整体安全衬的效益

在伯利恒炼钢公司雀点分厂板坯连铸中间包上采用低水泥浇注料安全衬取代砖砌安全衬，延长了中间包的使用寿命，降低了维修费用。     

等离子喷涂Sm_2Zr_2O_7热障涂层残余热应力

采用有限元分析软件ANSYS对等离子喷涂Sm2Zr2O7热障涂层在金属基体材质类型、厚度、半径变化时涂层的残余热应力进行了分析。结果表明,金属基体的热膨胀系数对Sm2Zr2O7热障涂层的残余热应力有着显著影响,金属粘结层与表面陶瓷层界面处的残余应力及其应力梯度随着金属基体热膨胀系数增加而增大。金属基体厚度和半径不是影响Sm2Zr2O7热障涂层残余应力的主要因素。     

硅烷交联聚乙烯/尼龙6阻隔材料的研究

通过硅烷交联聚乙烯与尼龙6共混制备阻隔材料,研究了硅烷交联聚乙烯的交联时间及尼龙6含量对复合材料阻隔性能、力学性能及热性能的影响。结果表明:随着交联时间的增长,材料的阻隔性能有所提高,当交联时间为6h时,表现出良好的阻隔性能;尼龙6含量对材料的阻隔性能和力学性能具有双重影响,当尼龙6含量为16%时,阻隔材料综合性能较好。     

Effect of material properties on residual stress distribution in thermal barrier coatings

Residual stress has a significant influence on the crack nucleation and propagation in thermal barrier coatings (TBC) system. In this work, the residual stress in the air plasma spraying (APS) TBC system during cooling process was numerically studied, and the influence of the material properties of each layer on the residual stress was investigated. The morphologies of the interface were described by a piecewise cosine function, and the amplitude for each segment gradually increases. The elasticity, plasticity and creep of top coat (TC), thermally grown oxide (TGO) layer and bond coat (BC) were considered and the elasticity and creep of the substrate layer were taken into account. The material properties of all layers vary with temperature. The results show that the material properties have complex influence on the residual stress during cooling. The effect of the material properties of TC and BC on the residual stress at the interface is relatively large, and that of TGO and substrate is relatively small. These results provide important insight into the failure mechanism of air plasma spraying thermal barrier coatings, and important guidance for the optimization of thermal barrier coating interfaces.     

Thermal properties of homogenous lanthanum hexaaluminate/alumina composite ceramics

Lanthanum hexaaluminate has the potential to be applied in thermal barrier coatings due to its relative low thermal conductivity and low sinterability at temperatures higher than 1100 °C. One of the main problems in developing this material as a thermal barrier coating is difficulty in controlling the microstructure in order to combine the low thermal conductivity with high structural reliability.The idea behind this study was to take advantage simultaneously of the low thermal conductivity of lanthanum hexaaluminate and of the high mechanical properties of alumina by developing alumina-rich and lanthanum hexaaluminate-rich alumina/lanthanum hexaaluminate ceramic composites. The thermal properties of the alumina/hexaaluminate ceramic composites were compared as a function of temperature and lanthanum hexaaluminate content (20–80 vol.%). The results showed that the alumina/lanthanum hexaaluminate ceramic composites have sufficient low thermal conductivity to be used in thermal barrier coatings.     

废聚苯乙烯泡沫塑料的回收利用

综述了将废聚苯乙烯泡沫塑料制成涂料，粘合剂，增塑剂，苯乙烯单位等有机产品的方法。既减少了环境污染，又有一定的经济效益。     

(氟)硅橡胶-金属高温硫化粘接的研究

研究了（氟）硅橡胶与金属的高温硫化粘接,结果表明乙烯基三过氧叔丁基硅烷是硅橡胶（甲基乙烯基硅橡胶或氟硅橡胶）高温硫化粘接的良好增粘剂。溶液浸蚀分析证明硅橡胶与金属粘接界面的相互作用力包括色散作用和化学键作用。     

Failure of the plasma-sprayed coating of lanthanum hexaluminate

Lanthanum magnesium hexaluminate (LaMgAl₁₁O₁₉, LMA) is an attractive material for thermal barrier coatings (TBCs), and the failure of its coating was studied in this work by thermal cycling, X-ray diffraction, dilatometric measurement and thermal gravimetric-differential thermal analysis. The dilatometric measurement indicates that even though the bulk material of LMA has a higher sintering-resistance than the typical TBC material, i.e. yttria-stabilized zirconia (YSZ), the plasma sprayed coating of LMA has two serious contractions due to the re-crystallization of LMA and phase transitions of alumina. LMA has similar thermal expansion behaviour with alumina, leading to a good thermal expansion match between LMA and the thermally grown oxide layer. On the other hand, the plate-like structure of LMA not only results in a low thermal conductivity, low Young's modulus, but also a high stress tolerance, and these are believed to be the reasons for the long thermal cycling life of LMA coating.     

Thermal Stability of Lanthanum Zirconate Plasma-Sprayed Coating

Lanthanum zirconate (La₂Zr₂O₇, LZ) is a newly proposed material for thermal barrier coatings (TBCs). The thermal stability of LZ coating was studied in this work by long-term annealing and thermal cycling. After long-term annealing at 1400°C or thermal cycling, both LZ powder and plasma-sprayed coating still kept the pyrochlore structure, and a preferred crystal growth direction in the coating was observed by X-ray diffraction. A considerable amount of La₂O₃ in the powder was evaporated in the plasma flame, resulting in a nonstoichiometric coating. Additionally, compared with the standard TBC material yttria-stabilized zirconia (YSZ), LZ coating has a lower thermal expansion coefficient, which leads to higher stress levels in a TBC system.     

水性隔热保温节能涂料的制备研究

以丙烯酸弹性乳液为基料,空心玻璃微珠、金红石型钛白粉、云母及空心硼硅酸盐等为颜填料制备隔热保温涂料,该涂料性能稳定、表面光滑、涂层薄,耐沾污、热反射效率高,隔热性能良好,适应范围广。     

Micropatterning of photosensitive glass-ceramic-polymer composite by sand blasting

Abstract

A photosensitive, sandblasted composite was used to achieve a high aspect ratio of barrier ribs. The authors investigated the erosion of the photosensitive composite prepared with two different pastes: normal and photosensitive. The barrier ribs underwent micropatterning with calcium carbonate powder as the sand blasting erodent material. The patterned green barrier ribs were fired in an air atmosphere and the thermal, physical and mechanical properties of the resulting composites were determined by thermal gravimetric analysis, atomic force microscopy, nanoindentation, and peel testing. The photosensitive composite had better adhesion with a dry film resist and showed lower porosity, surface roughness, stiffness and elastic modulus than a normal composite, which was attributed to the remaining polymer. In the process, the developed photosensitive composite and the dry film resist film were able to withstand the impact of the separated particles or clusters. These results support the use of sand blasting to fabricate the micropatterning of barrier ribs with two layers of photosensitive composite.