帝人试制成功树脂一体成形的全景车顶

帝人向媒体展示了使用树脂将窗框与车窗一体成形的全景车顶(Panoramic Roof)。该车顶的面积相当大,达到了1.7平方米。此次通过与日本名机制作所共同开发成形设备,在大面积成形工件上实现了均匀成形。两公司共同开发的成形设备,可将车窗原料透明PC(聚碳酸酯)与窗框原料黑色PC/PET(聚对苯二甲酸乙酯)这2种不同种类的树脂整体射出冲压成形。该设备是能够成形面积达2平米的的大型设备,合模压力高达3400t。成形设备的形状为:在车窗与窗框2个型腔模之间,配置有两面加工成型芯形状、称为“中子”型芯模。成形的原理是,当车窗部分成形之后,使中子旋转,继续对窗框部分进行2次成形。由于采用的是在模具张开一定程度的状态下射出树脂,然后通过冲压使树脂遍布模具内的方式,因此与一般的射出成形相比,模具内树脂的压力分布易于保持均匀。当然,要想使全景车顶这样的大面积工件均匀地成形,仅凭上述这些条件是不够的。为此,帝人苦心研制出了使模具在保持平行的状态下进行开闭的机构。对作为模具驱动机构的4根带有致动器(油压式)的轴,利用计算机分别进行精密控制,以保证平行。通常如果模具倾斜,即使在成形件的厚度本来应该均匀的区域,也会随着部位不同而出...     

中国陶瓷工业应加强粉料压力成形技术及装备的研究与开发

从古至今,世界陶瓷制品生产工艺基本上走的是物料(原料)由干法变湿法又由湿法变干法(产品)的路子,即干→湿→干.尽管是绕弯路,但目前尚未找到更好的方法.此工艺以制坯原料的形态来划分,有注浆成形、塑性成形和粉料压力成形(干压或半干压)三大基本方法.选用何种工艺方法并无特殊的规定,而是由各企业根据本身的条件和产品结构特点具体制定.即使在同一工艺方法中也可再细分.例如卫生洁具的注浆成形又有管道压力注浆、微压注浆、高压注浆等.在现有的三大方法中由湿变干走的路最短者,当推粉料压力成形法.假定坯体入窑水分定为1%,注浆成形坯体需脱水分26%以上;塑性成形坯体需脱去水分18%以上;而粉料压力成形坯体最多只需脱去水分5%～6%.坯体脱水工艺就是干燥,需要很大的投资.而粉料压力成形坯体干燥成本要低得多.     

Incoloy825+12Cr2Mo1R复合板封头冲压加工研制

煤焦油深加工项目中的核心设备沥青预处理塔设计材料为Incoloy825(复层)+12Cr2Mo1R(基层)复合板。由于材料的特殊性和使用工况的复杂性,要求成形后封头即耐热又耐蚀。封头成形是本设备制造中的难点。采用高温热冲压成形和随后的正火加回火热处理,封头的各项技术指标达到了设计要求。文中介绍了复合板Incoloy825+12Cr2Mo1R材料特性,封头成形工艺,热处理工艺和合格指标。     

奥氏体不锈钢炉体应力腐蚀破裂失效分析

316L不锈钢是一种耐蚀性能很好的材料，但是安装质量特别是焊接质量对其应力腐蚀破裂(SCC)性能有很大的影响，针对抚顺石化多次沿焊接热影响区(HAZ)发生断裂事故的一套316L不锈钢设备进行失效分析，认为该设备的断裂属于SCC，焊接接头质量差是造成断裂的根本原因。     

非标设备不可展部件成形的工艺技术

论述了石油化工非标准设备 (以下简称非标设备 )不可展部件的定义、成形方式、成形模具和成形的工艺技术。不可展部件的加工制作有一定的难度 ,熟练地掌握其成形的工艺技术 ,对降低非标设备的制造成本、提高产品的质量具有重要的意义     

干压结合冷等静压成形对陶瓷力学性能的影响

本文通过研究在不同压力下进行干压结合冷等静压成形过程对陶瓷素坯体和烧结体的结构、性能的影响,得出了最佳的成形工艺条件,即干压压力为20T、冷等静压压力为200MPa。     

热量再生的甲醇精馏工艺及装置

<正>对粗甲醇精制工艺和设备,包括至少三个蒸馏阶段操作级联降低压力,其中第一阶段(200)工作在最大蒸馏压力(P2),第二阶段(300)工作在一个中等蒸馏压力(P3),和最后的蒸馏阶段(400)操作最小的蒸馏压力(P4),其中第一阶段和蒸馏阶段均产生相应的蒸馏甲醇气体流(204,304),不同的溶液都包含作为下一阶段的原料甲醇。在最开始的气流中     

意大利SITI压机模具的设计

１　前言瓷砖由于形状规整、尺寸要求严格,一般采用压机压制成形,也就是通过对布置于模腔中的含水在４％～６％的粉料施加一定的压力而获得所需形状、尺寸和密度的坯体。为了保证最终产品———瓷砖在加工及质量上的要求,坯体必须“压制完好”。压机是最初的设备,只有压机及模具几何尺寸良好,在挤压成形阶段中才能保证压力均匀,获得完美的挤压产品,即坯体。我公司引进了意大利ＳＩＴＩ公司８０３型和１７０３型压机,在压机定型的情况下,如何保证压制的坯体完好,关键在于压模的几何尺寸是否良好,而要保证压模几何尺寸良好,首先要…     

德国Lippert Gains推出陶瓷茶具压力注浆成型新设备

德国Lippert Ganins最近推出了TDG／500系列陶瓷茶具压力注浆成形新设备，该设备采用伺服控制轴来代替以往的水压装置，这样茶具杯子和把柄成形可一次浇注完成，不仅可满足多种器型设计的浇注成形需要，而且即使是成形复杂形状仍具有很高的精确度，     

应用塑压法生产深异形制品的探讨

通过应用塑压法生产异形制品，探讨了成形过程中各阶段的要求，压坯压力、充气压力及排气管的安装方式对石膏模型质量的影响。     

Thermal and mechanical properties of fiber reinforced high performance self-consolidating concrete at elevated temperatures

This paper presents the effect of temperature on thermal and mechanical properties of self-consolidating concrete (SCC) and fiber reinforced SCC (FRSCC). For thermal properties specific heat, thermal conductivity, and thermal expansion were measured, whereas for mechanical properties compressive strength, tensile strength and elastic modulus were measured in the temperature range of 20–800 °C. Four SCC mixes, plain SCC, steel, polypropylene, and hybrid fiber reinforced SCC were considered in the test program. Data from mechanical property tests show that the presence of steel fibers enhances high temperature splitting tensile strength and elastic modulus of SCC. Also the thermal expansion of FRSCC is slightly higher than that of SCC in 20–1000 °C range. Data generated from these tests was utilized to develop simplified relations for expressing thermal and mechanical properties of SCC and FRSCC as a function of temperature.     

Experimental study of filling capacity of self-compacting concrete and its influence on the properties of rock-filled concrete

Rock-filled concrete (RFC) was developed in China mainly for large-scale concrete construction. The distinctive casting procedure of RFC makes it highly dependent on the filling capacity of self-compacting concrete (SCC). This study investigated two of the most controversial issues regarding RFC—the filling performance of SCC and the large interface between SCC and rocks. These issues were examined through an experimental setup designed to stimulate SCC flow in rock skeleton. The effects of different factors (aggregate size, yield stress, etc.) on the filling capacity of SCC and the properties of RFC were investigated on the basis of filling rate, cross-section porosity, and interface microstructure. Two clogging mechanisms were summarized from literature and used to explain the experimental results. The findings indicate that the interface microstructure of RFC greatly depends on the filling performance of SCC which is significantly affected by the size and condition of the large rocks.     

Radiation-Induced Senescence Reprograms Secretory and Metabolic Pathways in Colon Cancer HCT-116 Cells

Understanding the global metabolic changes during the senescence of tumor cells can have implications for developing effective anti-cancer treatment strategies. Ionizing radiation (IR) was used to induce senescence in a human colon cancer cell line HCT-116 to examine secretome and metabolome profiles. Control proliferating and senescent cancer cells (SCC) exhibited distinct morphological differences and expression of senescent markers. Enhanced secretion of pro-inflammatory chemokines and IL-1, anti-inflammatory IL-27, and TGF-β1 was observed in SCC. Significantly reduced levels of VEGF-A indicated anti-angiogenic activities of SCC. Elevated levels of tissue inhibitors of matrix metalloproteinases from SCC support the maintenance of the extracellular matrix. Adenylate and guanylate energy charge levels and redox components NAD and NADP and glutathione were maintained at near optimal levels indicating the viability of SCC. Significant accumulation of pyruvate, lactate, and suppression of the TCA cycle in SCC indicated aerobic glycolysis as the predominant energy source for SCC. Levels of several key amino acids decreased significantly, suggesting augmented utilization for protein synthesis and for use as intermediates for energy metabolism in SCC. These observations may provide a better understanding of cellular senescence basic mechanisms in tumor tissues and provide opportunities to improve cancer treatment.     

A methodology to assess robustness of SCC mixtures

The present paper highlights the importance of a robust SCC mixture for the successful introduction of this innovative technology in the concrete industry. A methodology to quantify SCC mixture robustness is also proposed. A central composite design was carried out to mathematically model the influence of five mixture parameters and their coupled effects on deformability, passing and filling abilities and compressive strength of SCC mixtures. The target SCC mix composition, to be applied during full-scale tests in a precast factory, was selected to be the central point in the factorial design. The mixture parameters suggested by the Japanese SCC-designing method were adopted. The derived models were used to estimate SCC properties while mixture parameters variations were simulated, based on daily fluctuations inherent from production process. SCC robustness was assessed by measuring how frequently the properties of simulated mixes fall inside the acceptance intervals.     

Slow strain rate and constant load tests of A 285 and A 516 steels in Bayer solutions

Stress corrosion cracking (SCC) experiments were carried out on A 285 and A 516 steels by slow strain rate and constant load techniques. The influence of the impurities contained in Bayer solution on the susceptibility to SCC was studied. The results obtained by both techniques indicated that aluminate ions promote passivation but the oxide layer includes numerous defects and the SCC susceptibility increases. The slow strain rate experiments provided a rapid method for investigating caustic stress corrosion cracking and intensified the susceptibility to SCC compared to the results obtained by the constant load technique. In the passive potential region, some shallow cracks were detected only when the experiments were conducted at slow strain rate in solutions containing aluminate ions. The presence of such cracks indicated that anodic protection could not entirely prevent SCC in the Bayer solution.     

35CrMo和00Cr13Ni5Mo硫化氢环境应力腐蚀开裂

用慢应变速率拉伸实验和U形试样浸泡实验、电化学极化技术并结合微观分析手段,在湿硫化氢介质中研究了35CrMo和00Cr13Ni5Mo两种钢的应力腐蚀开裂行为规律。结果表明,35CrMo和00Cr13Ni5Mo钢在实验条件下均具有一定应力腐蚀开裂（SCC）敏感性,其敏感性随着溶液pH的降低和H₂ S浓度的增大而增大;00Cr13Ni5Mo 在实验条件下抗SCC的能力均高于同条件下的35CrMo,在pH3.0的溶液中,二者性能比较接近,在pH4.5的溶液中,00Cr13Ni5Mo 耐H₂S环境SCC的性能明显提高,高于35CrMo,这主要是因为00Cr13Ni5Mo中的耐蚀合金元素增强了其钝化膜的稳定性、降低了氢脆作用所致。     

Parameter-study on the influence of steel fibers and coarse aggregate content on the fresh properties of self-compacting concrete

Self-compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their propagation, and improve several characteristics and properties of the concrete. Fibers are known to significantly affect the workability of concrete. Therefore, an investigation was performed to compare the properties of plain SCC and SCC reinforced with steel fibers. Two mixtures of SCC with different aggregate contents were used as reference. Each of the concretes was tested with four types of steel fibers at different contents in order to answer the question to what extent the workability of SCC is influenced. The slump flow, a fiber funnel and the J-ring test were used to evaluate the material characteristics of the fresh concrete. This paper discusses the suitability of the applied test methods and the effect of the coarse aggregate content, the content and type of steel fibers on the workability of SCC.     

不同硫化物浓度碱性溶液中16Mn钢及热影响区应力腐蚀行为

利用U形弯试样浸泡实验和电化学技术研究了16Mn钢及其模拟热影响区在不同硫化物浓度的碱性(pH=11.7)介质中的应力腐蚀开裂(SCC)行为与机理。结果表明:16Mn钢原始组织、粗晶组织(空冷组织)和硬化组织(淬火组织)在碱性硫化物环境中均能形成保护性腐蚀产物膜、导致电极过程近似呈钝化状态,钝化电流密度依次降低;淬火组织析氢电流密度较高,腐蚀速度较低,长期服役后会造成靠近熔合线部分腐蚀深度大而暴露出残余拉应力区,引起SCC;HAZ中硬化组织、粗晶组织和原始组织在碱性硫化物环境下SCC敏感性逐渐降低,硬化组织具有较明显的SCC敏感性,粗晶组织和原始组织SCC敏感性小;硫化物浓度升高,16Mn钢及其模拟热影响区SCC敏感性增加;16Mn钢焊缝区在碱性硫化物环境中SCC裂纹扩展机制为阳极溶解机制。     

Use of different limestone and chalk powders in self-compacting concrete

This paper presents a study on the use of different types of limestone and chalk powders as fillers in self-compacting concrete (SCC) and their effects on superplasticizer demand and the strength properties of concrete mixes. It was found that all the different limestone and chalk powders selected could be used successfully for producing SCC mixes, although modest adjustments of superplasticizer dosage were necessary. Generally, higher superplasticizer dosages were required for SCC using chalk powder than for that using limestone powder. The fineness of the powders had little effect on the superplasticizer demand. The compressive strength of the SCC mixes containing the limestone and chalk powders was significantly greater than that of the conventional vibrated reference concrete at the same water/cement ratio, particularly at early ages.     

Phase angle analysis for stress corrosion cracking of carbon steel in fuel-grade ethanol: Experiments and simulation

The stress corrosion cracking (SCC) of carbon steel in simulated fuel-grade ethanol (SFGE) was investigated using electrochemical impedance spectroscopy (EIS) and slow strain rate test (SSRT). Phase angle at low frequency range (<1 Hz) is sensitive to SCC process of carbon steel in SFGE. Phase angle decreases during an active crack growth. Frequency at maximum phase angle also increases towards an active cracking region at around 1 Hz. A transmission line model (TLM) is used to simulate the EIS response for SCC based on real geometrical parameters. By systematically changing the values of the circuit elements, the activities of the sample surface, crack tip and crack wall were studied in detail. By comparing the Bode plots from both experiment and simulation during SCC, a detailed mechanistic picture is derived to describe the behavior of the stress corrosion crack on carbon steel in the fuel-grade ethanolic environment.