一种新型钛合金无缝管轧制过程中应力应变有限元模拟分析

以一种新型介稳定beta型Ti-Al-V-Cr-Mo-Nb-Sn系(名义成分:Ti-4Al-6V-7Cr-6Mo-3.5Sn-3.5Nb,wt%)钛合金管材为研究对象,利用Simufact有限元分析软件,构建了能够反映该合金管材在轧制压延过程中应力和应变场分布情况以及材料表面质点的运动情况的有限元模型,为同类别的钛合金管材的轧制工艺参数制定和优化提供理论指导。     

TA16钛合金管材拉伸性能及组织研究

对大变形轧制的TA16钛合金管材在不同温度下进行热处理,分析热处理温度对管材室温拉伸性能和显微组织的影响,选择最优工艺对管材进行热处理,测定室温拉伸性能及工艺性能。并对管材进行不同温度高温拉伸,分析温度对管材高温拉伸性能和拉伸断口形貌的影响。结果表明:在600~750℃热处理时,管材强度和塑性随着温度升高呈下降趋势,晶粒逐渐长大。在100~350℃高温拉伸时,管材强度随温度升高而降低,拉伸断口均出现颈缩,表现出塑性断裂特征。     

聚乙烯/镁合金复合材料层合板的制备及辊压机理研究

采用常温下的胶合-辊压制备法,制备出由覆层增强体镁合金(AZ31B)以及基体聚乙烯(PE)组成的"三明治式"复合材料层合板。探究了制备过程中施压静置压力、施压静置时间、辊压过程压下量对辊压过程中轧制力变化规律的影响;通过"咬入敲击法"和二次轧制,获得了层合板的刚度以及成品层合板二次轧制加工中的弹性回复率与覆层增强板和基板分别对压下量的贡献率。结果表明,层合板在辊压过程中,"咬入"过程轧制力会存在瞬间升高的冲击效果,"咬出"过程轧制力会缓慢卸载;施压阶段中的静置时间与静置压力对辊压过程中的轧制力变化有一定的影响;在二次轧制过程中,轧制力会随着压下量的增加而变大,但轧制力提升速率会随着压下量的增加逐步变小且设定压下量对层合板的弹性回复率、各组分压下贡献率与轧制效果均存在一定的影响。     

异型截面化工法兰轧制中导向辊的控制

导向辊的运动控制,是异型截面化工法兰轧制数值模拟中的关键和难点。以环轧过程中法兰体积不变原则为基础,利用数学软件MATLAB计算了导向辊的运动轨迹。将计算结果导入模拟软件ABAQUS中,对某一内台阶截面化工法兰径向轧制过程进行了数值模拟。结果表明,所提出的方法较好地控制了导向辊的运动,轧制过程进行平稳,为进一步研究异型截面法兰轧制提供了参考。     

导电辊电镀技术

0 前言 导电辊是冶金工业中轧制薄板化学处理、电解、电镀、热熔过程中,用来传递电流和引导薄板通过. 根据导电辊用途,其辊面镀层应满足如下要求: (1)良好的导电性能轧制钢板进行电化学处理时,通常电流在5 000～20 000 A.铜是良好的导电材料,钢辊表面镀铜是导电辊良好的选择.镀铜层厚度根据导电辊所需要通过的电流而定.铜层必须细致、均匀,电镀时通过的电流不应引起辊面发热而影响镀锡(锌)电解液的温度控制.如无须导电或不通过大电流的导电辊,为防止腐蚀,可选择镍为底镀层.     

玻纤增强聚丙烯缠绕管的层间性能及表观质量研究

采用缠绕成型工艺制备了玻璃纤维增强聚丙烯管材,考察了预热通道温度和芯模温度对管材内外壁表观质量的影响;同时分别单独研究了芯模温度、热风枪加热角度、预浸带张力、缠绕速度和压力辊径向压力对管材层间剪切强度(ILSS)的影响,对成型工艺条件进行了优化,并利用扫描电子显微镜(SEM)对层间破坏试样进行了微观表征。结果表明,适当提高预热通道温度可使管材获得较好的外壁表观质量,提高芯模温度可使管材获得较好的内壁表观质量;管材的ILSS随着热风枪加热角度及缠绕速度的增加而提高,达到一定值时又出现下降,随芯模温度、预浸带张力和压力辊径向压力升高而在总体上呈增加趋势;在预热通道温度为220℃、芯模温度为160℃、热风枪加热角度为6°、预浸带张力为24 N、缠绕速度为4.71 m/min、压力辊径向压力为0.15 MPa的最优工艺条件下制备的缠绕管材的内外壁表面光滑,ILSS达到了29.60 MPa;SEM分析表明,管材中树脂和纤维结合紧密,层间粘结良好。     

轧钢过程中宽带热轧工作辊热凸度变化的研究

工作辊热凸度与轧制时间、轧制速度、轧制节奏、轧辊冷却水等有着密切的关系,充分了解轧辊热凸度在轧制过程中的变化,不仅可以提高宽带钢热连轧机组热辊形的模型控制及预报精度,而且可以通过及时调整轧制节奏,轧辊冷却水系统的工作情况调整轧辊热凸度,对于板形控制具有重要意义。     

工艺条件对两步法缠绕成型连续玻璃纤维增强聚丙烯管材层间剪切强度及树脂含量的影响

本文以熔融浸渍法制备的预浸带为原料,通过两步法缠绕成型工艺制备了连续玻璃纤维增强聚丙烯管材,采用正交试验研究了工艺条件对管壁层间剪切强度及管材树脂含量的影响。结果表明,提高芯模压力辊温度、热风枪温度、预热器温度,选择适中的压力辊压力,在层间剪切强度提高的同时,树脂含量下降,当芯模压力辊温度为160℃、热风枪温度为260℃、预热器温度为170℃、压力辊压力为0.15MPa时,综合性能最好,其中层间剪切强度为20.47MPa,树脂含量为45.58%,芯模压力辊温度对层间剪切强度的影响最大。     

轧制工艺对柔性石墨力学性能的影响

研究了柔性石墨生产过程中初压力、轧制方向、轧制咬入角和轧制辊径等因素对其宏观力学性能的影响,结合对不同密度的柔性石墨取向度的分析,对柔性石墨的强度机制作了进一步的探讨。     

NiTi形状记忆合金特性及管材的研究进展

NiTi形状记忆合金管材在微创外科及介入内镜检查学等医学领域中取得了广泛的应用。NiTi形状记忆合金管材的成型方法包括挤压、轧制、旋锻、拉拔等方法。目前,医用NiTi形状记忆合金成品管材的制备仍然以拉拔工艺为主。同时,也要探索NiTi形状记忆合金管材加工的新技术、新工艺。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

粉煤灰中烧失量检测的不确定度分析

以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。     

生物油的成分分析及物性测定

以添加FeCl2的ZnCl2-KCl混合熔盐裂解纤维素和秸秆,制得生物油。采用傅立叶变换红外光谱法和气相色谱-质谱法分析生物油的成分。结果表明,生物油中成分复杂,含有氧元素、多种有机化合物,主要包括酮类、醛类、酚类及羧酸类等。测定了20～80℃生物油的密度和粘度,发现生物油的密度与温度呈较好线性关系,而生物油的粘度均大于水的粘度,且不同熔盐体系对秸秆生物油的粘度无较大影响。     

分解炉扩径的技术改造

我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉     

Process of acceleration of filtration of viscose

Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969.     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003