Effect of abrasive blasting on the internal surface of L80-13Cr tubing and casing

In this study,two sandblasting textures,namely,quartz and high-chromium(Cr)stainless steel sands,were used for sandblasting of the internal surface L80-13Cr tubing and casing.The contrastive analysis on the properties of the pipes before and after abrasive blasting was conducted,including the metallographic phase detection of the internal surface,simulating accelerated corrosion tests,and residual stress tests for the pipe after abrasive blasting.Based on the analysis results,it is explained why the API standard requires that no scale appears on the internal surface of L80-13Cr and iron contamination when internal sandblasting media are applied.The results show that abrasive blasting can effectively remove scales on the internal surface of L80-13Cr tubing and casing and improve corrosion resistance.The abrasive blasting process does not produce obvious residual stress on the internal surface of the tubing and casing.Also,the de-rusting effect of stainless sand is better than that of quartz sand,and the former does not produce iron contamination.

Regardless of the Puncture Angle, a Tuohy Needle with Sand-Blasted Steel at the Tip of the Bevel Is a Valid Needle on the Ultrasonic Images

Background: A high ability to visualize the needle on the ultrasonic images is necessary to perform the ultrasound-guided nerve block safely. The Rafa Tuohy needleR (Vygon, Paris, France, Rafa) is a non-stimulating Tuohy needle with sand-blasted steel at the tip of the bevel. We examined the degree to which the Rafa enhanced the visibility of ultrasonic images compared with the non-coated Tuohy needle. Methods: We punctured the Blue Phantom. The dimensions of both the Rafa and the non-coated Tuohy needles were 18 G × 80 mm. The puncture angle is 30 degrees and 45 degrees from the Blue Phantom. We measured the intensity of the tip of the bevel at a depth of 0.5, 1.0, 1.5 and 2.0 cm for the puncture angle of 30 degrees, and 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm for the puncture angle of 45 degrees. Six anesthesiologists with more than seven years of experience performed three punctures using each needle. Results: As an outcome, we concluded that at a puncture angle of both 30 degrees and 45 degrees, the intensity of the non-coated Tuohy needle decreased with the depth. On the other hand, at an angle of 30 degrees, the intensity of the Rafa needle did not decrease, and at an angle of 45 degrees the intensity only decreased very slightly as the depth increased. Conclusions: The Tuohy needle with sand-blasted steel at the tip of the bevel provided greater visualization than the non-coated Tuohy needle on the ultrasound images.

Synthesis of (Ca, Mg)-α′-Sialon-AlN-BN powders from boron-rich blast furnace slag by microwave carbothermal reduction-nitridation

(Ca, Mg)-α′-Sialon-AlN-BN powders were synthesized by the carbothermal reduction and nitridation (CRN) method using boron-rich slag, one of the intermediate products from pyrometallurgy separation of pageit, as the staring material. The influences of synthesis temperature and holding time on the phase composition and microstructure during the microwave CRN were studied by XRD, SEM and EDS. The comparison between two heating techniques, conventional and microwave heating, on the synthesized powder was presented as well. The experimental results revealed that the phase compositions and microstructures of the synthesized products were greatly affected by the synthesis temperature and holding time. With an increase in the synthesis temperature or holding time, the relative amount of α′-Sialon increased and α′-Sialon became the main crystalline phase at 1400 °C for 6 h. The synthesized products also contained AlN, BN and a small amount of β-SiC. Elongated α′-Sialon grains, short rod AlN grains, aggregate nanoscale BN grains were observed in the synthesized powders. The reaction temperature of microwave heating method was reduced by 80 °C, the reaction time was shortened by 2 h, and more elongated α′-Sialon grains with large aspect ratio were observed.

Experimental analysis of sand particles' lift-off and incident velocities in wind-blown sand flux

The probability distributions of sand particles＇ lift-off and incident velocities in a wind-blown sand flux play very important roles in the simulation of the wind-blown sand movement. In this paper, the vertical and the horizontal speeds of sand particles located at 1.0 mm above a sand-bed in a wind-blown sand flux are observed with the aid of Phase Doppler Anemometry （PDA） in a wind tunnel. Based on the experimental data, the probability distributions of not only the vertical lift-off speed but also the lift-off velocity as well as its horizontal component and the incident velocity as well as its vertical and horizontal components can be obtained by the equal distance histogram method. It is found, according to the results of the X^2-test for these probability distributions, that the probability density functions （pdf＇s） of the sand particles＇ lift-off and incident velocities as well as their vertical com- ponents are described by the Gamma density function with different peak values and shapes and the downwind incident and lift-off horizontal speeds, respectively, can be described by the lognormal and the Gamma density functions, These pdf＇s depend on not only the sand particle diameter but also the wind speed.

Changes in Protein Content and Chitinase and β-1,3- glucanase Activities of Rice with Blast Resistance Induced by Ag-antibiotic 702

[Objective] The paper was to explore the effect of rice blast resistance induced by Ag-antibiotics 702 on protein content and chitlnase and β-1,3-glucanase activities in rice. [ Method] At the fourth leaf stage of Luliangyou 996, 15 μg/mL Ag-antibiotic 702 was sprayed, while Validamycin and distilled wa- ter were sprayed as positive control and negative control, respectively. All treatments were inoculated with spore fluid of Magnaporthe grisea at 48 h post spraying, and the rice inoculated with only distilled water was used as blank control. The enzymes activities （endochitinase, exochitinase and β-1,3-glucanase） and total pro- tein content in rice leaves were determined every 24 h within 168 h post spraying. [ Result] Compared with the blank control, the rice inoculated with spore fluid of M. grisea could significantly increase the total protein content and the activities of β-1,3-glucanase and chitinase. The induction effect of Ag-antibiotics 702 exceeded that of Validamycin treatment. And the changes in activities of β-1,3-glucanase and chitinase had obvious synchronicity. [ Conclusion] Ag-antibiotic 702 can significantly improve the total protein content and the activities of β-1,3-glucanase and chitinase, thus enhancing the resistance to rice blast.

Self-aggregating behavior of poly(4-vinyl pyridine)and the potential in mitigating sand production based onπ-πstacking interaction

Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline.In this study,the poly(4-vinyl pyridine)(P_(4)VP)incorporated with self-aggregating behavior was proposed for sand migration control.The P_(4)VP could aggregate sand grains spontaneously throughπ-πstacking interactions to withstand the drag forces sufficiently.The influential factors on the self-aggregating behavior of the P_(4)VP were evaluated by adhesion force test.The adsorption as well as desorption behavior of P_(4)VP on sand grains was characterized by scanning electron microscopy and adhesion force test at different pH conditions.The result indicated that the pH altered the forms of surface silanol groups on sand grains,which in turn affected the adsorption process of P_(4)VP.The spontaneous dimerization of P_(4)VP molecules resulting from theπ-πstacking interaction was demonstrated by reduced density gradient analysis,which contributed to the self-aggregating behavior and the thermally reversible characteristic of the P_(4)VP.Dynamic sand stabilization test revealed that the P_(4)VP showed wide pH and temperature ranges of application.The production of sands can be mitigated effectively at 20-130℃ within the pH range of 4-8.

Development and Application of Al_2O_3-Si_3N_4 Refractories Used in Blast Furnace

Newly developed Al2O3-Si3N4 composite refractories used for blast furnace is introduced in this work. Al2O3-Si3N4 composite refractories attacked by alkali vapor and blast furnace slag was investigated. High performance Al2O3-Si3N4 composite refractories was produced and used at both 2560m^3 blast furnaces of Tan-gsteel and No. 5 blast furnace of Shaosteel.

喷砂对MCrAlY-单晶高温合金界面组织影响研究

目的 研究在单晶表面喷砂预处理对MCrAlY-单晶高温合金界面的组织的影响。方法 对单晶基材进行不同载荷条件下的喷砂处理(包括无喷砂、轻喷砂及重喷砂),然后采用超音速火焰喷涂(HVOF)工艺在单晶试样上制备MCrAlY涂层,观察高温氧化后涂层-单晶界面组织的演变。真空热处理后,首先对基材和涂层的微观组织结构进行扫描电镜观察表征,然后对涂层进行1 050℃的高温氧化试验,保温287 h后,继续采用背散射电子模式观察TCP相的析出行为,测量并绘制互扩散区和二次反应区析出厚度柱状图。结果高温氧化热暴露过程中,涂层和基体之间发生了明显的元素互扩散现象,喷砂处理对互扩散区大小,尤其是二次反应区的深度,有着显著影响。在该高温氧化试验条件下,轻喷砂和重喷砂对互扩散区厚度的影响不大(重喷砂17.5μm,轻喷砂20μm),但显著促进了SRZ的析出厚度(重喷砂52.5μm,轻喷砂40μm)。结论 喷砂会导致单晶内产生塑性变形(形成GPDZ),且重喷砂会析出更深的二次反应区,对于包覆型MCrAlY涂层在单晶热端部件的表面应用,应当对单晶表面实施轻喷砂或无喷砂处理。

Non-water Injection Mix for Blast Furnace YB/T 4153-2006

1 Scope This standard specifies the classification, techni cal requirements, test methods, quality appraisal pro- cedures, packing, marking, transportation, storage, quality certificate, and construction manual of nonwater injection mix for blast furnace.

严重生物降解原油GC-MS特征及油源对比

图牧吉油砂位于松辽盆地边缘,搞清它的油源对于该地区的油气勘探有着十分重要的意义.气相色谱-质谱分析表明,该样品受到了严重的生物降解,部分用于对比的甾、萜烷生标标志物受到了降解,使与之有关的参数值发生了变化,给油源对比带来了困难.……

WC-Co-Cr涂层和0Cr13Ni5Mo基材的气体喷砂冲蚀行为

研究不同结构HVOF热喷WC-Co-Cr涂层和0Cr13Ni5Mo基材的冲蚀行为,重点分析高速粒子冲击下涂层孔洞和层状结构等缺陷在不同攻角下的作用,提出高攻角气体喷砂冲蚀模型,解释了WC-Co-Cr涂层和0Cr13Ni5Mo基材的冲蚀行为规律。结果表明:低攻角时,涂层与基材的损伤机制均以微切削去除为主,涂层还伴有少量剥落,WC-Co-Cr涂层的耐冲蚀性能一般优于基材,但高孔隙率涂层更易切削导致冲蚀率比基材高。随攻角增大,涂层冲蚀率呈上升趋势而基材冲蚀率下降。高攻角时,层状结构明显的涂层其裂纹更易在层间萌生和扩展导致片状剥落,高孔隙率反而有利于吸收冲击能量和抑制裂纹扩展;基材则出现严重塑性变形。在气体喷砂条件下,涂层的层状结构对法向冲击极为敏感,攻角高于45°后,WC-Co-Cr涂层的冲蚀率为基材的1.3～4.1倍。

爆炸-强夯联合加密饱和砂基的工程实践

爆炸加密饱和砂是近年来码头建设中采用的一种新方法，加密深层饱和砂效果尤为明显；强夯法是传统的加密松散介质方法，但其有效影响深度一般不超过6m。通过试验，将两种方法结合起来用于加密陆域推填的饱和砂层取得了很好的效果。本文结合南方某电厂陆域推填饱和砂的加密工程，介绍了这一新工艺的施工方法及检测结果，说明该工艺用于饱和破的加密是完全可行的。

淀粉液化芽孢杆菌β-1,3-1,4葡聚糖酶基因的克隆和表达

提取淀粉液化芽孢杆菌(Bacillusamyloliquefaciens)基因组,通过PCR克隆了该菌的β-1,3-1,4葡聚糖酶基因全长。结果显示,该基因全长843bp,ORF为717bp,编码239个氨基酸,计算相对分子质量为26800,等电点为6.07。经Blast分析,该序列与基因库中的淀粉液化芽孢杆菌(M15674)同源性最高(97%)。该基因已被GenBank接受(AY205562.1)。用BamH和Xho双酶切目的片段和表达载体pET-30a(+)后相连接,构建了重组表达载体pET-amy,并导入BL21细菌中表达,酶学特性表明SDS-PAGE电泳在26000左右有表达蛋白带,该工程菌总酶活达90.74U/mL,是出发菌的3倍,最适温度在60℃左右,pH值在4～10之间。该工程菌可作为酶活高的理想材料,用以构建耐热性好和酶活高的杂合基因工程菌。

氧化锆陶瓷-复合树脂粘结界面耐老化性能的研究

目的探讨对氧化锆瓷层不同表面处理后,结合硅烷偶联剂的应用,通过人工老化实验,对比氧化锆瓷表面与复合树脂之间剪切粘结强度的影响,为临床应用提供依据。方法将120个试件随机分成酸蚀、喷砂、喷砂加酸蚀、空白组4组,各组再分为涂布硅烷偶联剂组和对照组,充填复合树脂2 mm。经人工老化实验后,利用万能试验机对比其剪切粘结强度。结果氧化锆瓷层表面3种表面处理组,酸蚀并结合硅烷偶联剂组所获得的粘结强度最大,喷砂组其次,喷砂加酸蚀组最低。结论经过3种不同表面处理后,均能提高瓷层表面与复合树脂之间的粘结剪切强度,酸蚀组效果最佳。通过耐老化实验比较分析瓷表面应用硅烷偶联剂有利于提高瓷与复合树脂间的粘接强度。

钴铬合金表面喷砂及烤瓷厚度对金-瓷结合强度影响

目的探讨不同的喷砂处理及瓷层厚度对钴铬合金烤瓷冠金-瓷结合的影响。方法处理因素有两点:①喷砂直径,60目及90目的氧化铝,压力为0.4MPa,②瓷层厚度,1.5mm及2.0mm。实验分为四组:A组,60目砂、1.5mm厚度瓷层;B组,60目砂2.0mm厚度瓷层;C组,90目砂1.5mm厚度瓷层;D组,90目砂2.0mm厚度瓷层。按照要求制作剪切强度试件,用万能试验机进行剪切强度测试。应用SPSS10.0软件进行统计学分析。结果各实验组抗剪切强度分别为:A组33.5987±5.3926MPa,B组29.0446±2.4165MPa,C组27.9936±2.7097MPa,D组21.9586±0.2209MPa;统计分析结果表明,A组与D组之间的差异有统计学意义(P<0.05),而其余各组之间的差异均无统计学意义。结论喷砂用的氧化铝粒径较大者,钴铬合金表面的金瓷结合力较强;1.5mm瓷层组的金瓷结合力大于2.0mm瓷层组。

喷砂工艺对金属-橡胶缓冲条结合强度的影响研究

采用不同喷砂工艺参数对金属-橡胶缓冲条中铝合金基体表面进行喷砂毛化预处理。研究了铝合金基体表面粗糙程度对金属-橡胶缓冲条中铝合金基体与橡胶层之间结合力的影响。结果表明,橡胶层与铝合金基体的结合力受到铝合金基体表面粗糙程度很大的影响。对于金属-橡胶缓冲条(其中基体为6063-T5铝合金、橡胶为复合橡胶)的结合力,有一个最合适的基体表面粗糙度值。喷砂时间为10s,喷砂距离在40mm、磨料粒度80目、气压0.7MPa、角度60°时,结合力最好。

Polyacrylamide hydrogel application in sand control with compressive strength testing

Sand production is one of the major problems in sandstone reservoirs. Different mechanical and chemical methods have been proposed to control sand production. In this paper, we propose a chemical method based on using polyacrylamide/chromium triacetate hydrogel to investigate sand production in a synthetic sandpack system. To this end, a series of bulk experiments including the bottle test and rheological analysis along with compression tests were conducted. Experimental results indicated that the compressive strength of the sandpack was increased as much as 30 times by injecting 0.5 pore volume of hydrogel. Also, it was found that the increases in cross-linker and polymer concentrations exhibited a positive impact on the compressive strength of the sandpack, mostly by cross-linker concentration(48 psi). Hydrogel with a higher value of cross-linker could retain its viscoelastic properties against the strain which was a maximum of 122% for 0.5 weight ratio of cross-linker/polymer. The presence of salts, in particular divalent cations, has a detrimental effect on the hydrogel stability. The maximum strain value applied on hydrogel in the presence of CaCl_2 was only about 201% as compared to 1010% in the presence of distilled water. Finally, thermogravimetric analysis and its derivative showed that the hydrogel could retain its structure up to 300 °C. The results of this study revealed the potential application of the hydrogel to control sand production.

碱热处理对Ti-Ta复合材料表面组织结构的影响

Ti-Ta复合材料具有比强度高、模量低和生物相容性好等特点,在生物医疗和化工等领域具有重要应用。本文选用Ti和Ta两种粉末为原料,通过放电等离子烧结与热变形方法制备高致密的Ti-20%Ta(摩尔分数)复合材料。通过表面喷砂和碱热处理改性材料表面状态,对材料进行显微组织分析。结果表明:Ta颗粒均匀分布在Ti基体中,Ta与Ti的界面具有一定的成分梯度,但扩散范围较小。相较于喷砂处理的Ti-Ta复合材料表面,经过喷砂与碱热双重处理的Ti-Ta复合材料具有更好的细胞相容性。改性后Ti-Ta复合材料生物学性能改善的原因可能是表面形成的纳米孔隙结构有助于蛋白质吸附,以及表面生成的钛酸钠与钽酸钠对蛋白质有更好的吸附性。因此,表面碱热处理是提高Ti-Ta复合材料生物相容性的有效手段。

抛丸清理技术的起源与发展史(1870年-1954年)

本文介绍了抛丸、喷丸、喷砂清理技术的发展史,及其领域的重要人物、相关发明及重要事件。

喷砂处理对Al-Zn-Mg合金焊接接头应力腐蚀性能的影响

采用慢应变速率应力腐蚀方法研究喷砂处理对高速列车车体材料A7N01铝合金焊接接头应力腐蚀性能的影响。试验结果表明,经喷砂处理后,A7N01铝合金焊缝的残余拉应力转变为压应力,同时接头整体应力降低,趋于均匀分布。经喷砂处理后,A7N01铝合金焊接接头在3.5%NaCl中的应力腐蚀敏感指数降低,断口未呈现脆性断裂特征,表明喷砂处理增强了其抗应力腐蚀能力。喷砂试样表面均匀分布的压应力,降低了在外加载荷作用下焊缝所承受的拉应力,增加了焊接接头的强度。同时,表面压应力层的存在抑制了接头在腐蚀环境中裂纹的萌生,从而减少腐蚀介质向内部的扩散和作用,增强了焊接接头的抗应力腐蚀能力。