水泥抗折强度与孔隙结构的关系

本文从钢渣水泥入手，研究了水泥抗折强度与孔隙结构的关系，发现水泥抗折强度与浆体总孔隙率相关性不强，而与直径大于1000A的大孔数目密切相关。     

水泥抗折强度试验机的设计

笔者从机械结构、控制电路和计算机软件等方面入手，设计、开发和研制成功了机电一体化的SYZ新型全自动水泥抗折强度试验机(简称水泥抗折机)；并且可对已有电动抗折仪进行了改造，制成改造型全自动水泥抗折机。     

低水泥刚玉浇注料的高温抗折强度研究

采用板状刚玉、电熔白刚玉、工业氧化铬微粉、α-Al2O3微粉、Secar71水泥、烧结尖晶石粉为原料,研究了水泥、α-Al2O3微粉、氧化铬微粉、尖晶石粉以及烧成温度对低水泥刚玉基浇注料高温抗折强度的影响。研究结果表明:烧成温度、水泥、尖晶石和α-Al2O3微粉对低水泥刚玉基浇注料的高温抗折强度影响较大。烧后膨胀越大,高温抗折强度越低;1700℃烧后试样的高温抗折强度高于1600℃烧后试样的高温抗折强度;控制加热永久线变化率,添加合适的水泥、α-Al2O3微粉和粒度细的尖晶石粉可以得到高温抗折强度高的试样。     

高温抗折强度自动测试机

1.引言 MgO-C耐火砖普遍应用于氧气顶吹转炉、铁水包和电弧炉中,其发展始终与炼钢中出现的变化相关,并且主要靠经验来获取。此类耐火材料的任何发展变化,都需要清楚了解     

熟料强度偏低的原因分析及解决措施

YB集团HT公司近三年来熟料强度长期偏低,3 d抗压强度平均值27.0 MPa,28 d抗压强度平均值50.3 MPa,与同属新疆南疆区域的LX公司相比熟料各龄期抗压强度平均值低3.0~5.0 MPa。本文从两家公司进厂原燃材料、熟料率值控制和熟料中有害成分等方面进行对比分析,制定改进措施,取得了较好的效果。     

水泥水化物晶胶比对水泥抗折性能的影响

通过在水泥中引入晶体源调整水化物晶胶比以提高水泥的抗折性能,测试了引入不同晶体源的水泥胶砂强度及脆性系数,确定用CA调整水泥石的晶胶比较为适宜。测定了不同CA掺量时水泥砂浆膨胀率及强度,对试验结果进行了分析,得出了CA的最佳掺量。     

水泥熟料强度长期偏低原因分析及改进实践

有效控制生料配料中原材料带入熟料中Mg O、R_2O等有害成分,从进厂原材料预均化及搭配管理入手,将不同品位石灰石搭配使用,适当提高熟料KH,控制熟料f-CaO含量及水泥熟料强度主要特征值C_3S、C_2S矿物含量范围,加强熟料煅烧,工艺操作采用薄料快烧方式,加大窑内通风,减少窑内还原气氛,稳定回转窑热工制度,解决了水泥熟料强度长期偏低问题。     

磨损对套管抗挤强度影响的有限元分析

通过建立磨损后套管三维模型导入ANSYS有限元软件的方法,分析了不同磨损程度对弯曲套管和直套管抗挤强度的影响。结果表明,随着磨损深度的增加,弯曲套管的剩余抗挤强度逐渐降低,且磨损深度与弯曲套管剩余抗挤强度基本呈线性关系;弯曲也会降低套管的抗挤强度。     

水泥窑协同处置市政污泥熟料强度降低原因分析及对策建议

本文分析了水泥窑协同处置处置污泥后对熟料28 d强度的影响情况,从熟料KH值、硅率、铝率及w（f-CaO）的变化情况,分析了处置污泥后熟料强度降低的原因,并给出相应的对策建议。     

Improvement of flexural bond strength of zirconia-resin cement by surface patterning using sub-nanosecond UV laser

Zirconia is a dental material that shows excellent biocompatibility and high strength in clinical applications. This study aims to evaluate the effects of ultrafast laser applications. The surface nanostructures were classified into three groups. Group 1 was generated using the burst mode, with three different distances between dots: 52 µm (Group 1a), 104 µm (Group 1b), and 156 µm (Group 1c). Group 2 was processed using the scanning mode configuration, with a set of parallel lines. Group 3 was also processed using this scanning configuration creating a set of square-shaped patterning. Group 4 was the control group. After the surface treatments, a pair of zirconia specimens was bonded end to end with resin cement. Flexural bond strength (FBS) test was applied in a universal test machine. Multiple comparisons were performed using a one-way analysis of variance and the Tukey's HSD test. All the samples that were treated with the laser showed higher FBS values than the untreated surface. Using the burst mode, preformed circular-shaped surface on an angle of 90⁰ at 52 µm distance (Group 1a) showed the highest FBS values among all groups (p < .05). Groups 2 and 3 had significantly higher values than 1b and 1c.     

粗骨料颗粒级配对混凝土抗折强度的影响

粗骨料最大粒级及颗粒级配影响混凝土的抗折强度,本文主要研究了粗骨料最大粒级、粗骨料单级配、二级配、三级配对混凝土抗折强度的影响。研究表明,粗骨料的最大粒级及颗粒级配对混凝土抗折强度影响很大,合理的最大粒级和级配能够提高混凝土的抗折强度。     

Small scale fracture and strength of high-entropy carbide grains during microcantilever bending experiments

The fracture behaviour of (Hf-Ta-Zr-Nb)C high-entropy carbide grains was investigated by microcantilever bending experiments, and fracture related properties (e.g. strength, toughness) were determined using linear beam theory. Microcantilevers were FIB-milled from large grains with {001} and {101} orientations and were subjected to micro-bending experiments. SEM based fractographic analysis of the broken cantilevers revealed that approximately half of them fractured at the fixing position at FIB-induced surface cracks, while the rest of the beams failed at small cracks located at submicron size pores or inclusions. In all cases, fracture occurred on the {001} cleavage plane. The fracture strength of beams fractured at the fixing position was 11.8 ± 0.2 GPa, while the strength of the beams that failed at submicron defects was in the range of 3.8-8.9 GPa. The calculation of stress concentration in the vicinity of pores revealed that local stress field exceeded the value that induced cracking in ‘defect free’ beams.     

全钢子午线轮胎抽丝爆产生原因分析及对策

在我国部分矿区,车辆超载严重,轮胎静态负载率超过260％,轮胎圈部抽丝爆缺陷明显增加。国外的尼日利亚、沙特阿拉伯、科威特等常年高温国家．年平均气温超过30℃．最高地表温度超过60℃．轮胎圈部抽丝爆现象也较多。本文主要从车辆载荷、制动鼓结构、轮辋材料、司机驾驶习惯等方面进行分析,就如何降低抽丝爆缺陷提出建议。     

磷酸二铵装置现场漏料的原因分析及解决措施

传统法磷酸二铵装置固体物料和粉尘泄漏是造成现场环境污染的原因。分析胶带输送机隙缝带料、设备密封漏料、系统正压漏料和皮带粘结漏料的原因,提出更换耐热胶带、解决设备密封问题、调整系统至微负压和调整成品包裹工况等解决措施,通过改造成功解决了磷铵装置现场漏料的问题。     

浅谈试验小磨细度控制与大磨水泥强度的对应关系

惠州光大水泥公司在确定大磨生产水泥时各物料配比的情况下,以同样配比、同样物料进行了小磨试验,42.5R水泥粉磨至不同的比表面积,32.5R水泥粉磨至不同的45μm筛余,以各组试验强度与大磨生产水泥强度进行比较分析,确定大小磨强度,比表面积和45μm筛余控制差值。较好地实现了水泥质量的预前控制。     

CKP240水泥立磨常见故障分析及解决措施

由于CKP立磨结构复杂,维护工作要求高,操作难度大,一直是制约生产稳定运行的难题。本文介绍在生产过程中,针对该立磨出现的密封压盖螺栓断裂、加载装置频繁损坏、蓄能器菌形阀损坏、辊套炸裂等问题,提出了有效的技术改造措施,不仅彻底解决了以上各类问题,还消除了隐患,降低了维修成本,提高了设备可靠性。