我国棒材品种结构调整趋势及展望

结合国家产业政策对棒材品种结构调整的要求,对我国棒材品种结构现状、棒材轧机装备现状及其改造关键技术以及提高棒材性能的关键工艺进行了分析,探讨了棒材品种结构调整和工艺装备改造趋势,并建议棒材生产商,要想实现可持续发展,应以国内市场占有率和自给率为目标,加快品种结构调整和工艺装备改造步伐,着手研发和生产高性能钢筋,按需调整棒材品种结构。     

棒材计数装置的研究

分析了棒材成品输送过程中的运动规律,研究了棒材自动检测计数新方法及其相应的机电一体化装置。该装置采用机械和光电巧妙结合的方法,解决了棒材计数问题以及不规则排列对棒材计数的影响,实现了对棒材稳定、准确的自动计数与控制。     

浅谈设备的维护和管理

南钢精整厂是一个专门从事圆钢棒材后道精整加工处理的工厂,主要业务为提升圆钢棒材平直度、对圆钢棒材表面缺陷修磨处理、对圆钢棒材表面光洁度提升处理、对圆钢棒材的热处理以及圆钢棒材表面缺陷和内部缺陷的检测和查找。面对先进的设备、面对棒材产品的高质量要求,如何保证设备安全、可靠、稳定、精度运行,是设备管理部门面临和解决的重要课题。     

棒材轧制工艺特点与老式轧机的利用

从棒材生产工艺特点出发，分析影响棒材产品精度的主要因素，认为棒材生产多种形式并存是产品本身特点所决定。为旧有的棒材车间工艺及设备改造提供参考     

锻造工艺和时效处理对TC10钛合金组织和性能的影响

采用工艺A和工艺B 2种不同锻造工艺获得Ф130 mm的TC10钛合金棒材,研究了锻造工艺对棒材组织和力学性能的影响。同时研究了时效温度对TC10钛合金棒材组织和性能的影响规律。研究结果表明,工艺A获得的棒材组织均匀性好,且棒材性能的各向异性小;工艺B获得的棒材组织均匀性差,且棒材性能的各向异性大。TC10钛合金棒材的抗拉强度随时效温度升高先降低再升高,而塑性则随时效温度升高先升高再降低,棒材经875℃×2 h/WC+550℃×6 h/AC热处理可以获得良好的综合力学性能。     

连轧棒材厂连轧工艺及孔型系统简介

概述了攀长钢连轧棒材厂棒材线的生产工艺以及孔型设计的基本情况,并简要叙述了连轧棒材线的主要配套设施,为大家进一步了解连轧棒材厂的情况提供了基础资料,为进一步优化连轧棒材生产线工艺及配置打下理论基础。     

棒材穿水冷却过程温度场有限元分析

针对棒材穿水冷却过程,利用ANSYS有限元分析软件建立了棒材温度场预报模型,研究了棒材穿水冷却过程中的热边界条件,分析了棒材温度场的分布及其变化规律。该模型的计算结果与实测值吻合较好,能够准确地预测棒材穿水冷却后的温度分布和最终的组织。     

在线棒材计数系统现状与研究

随棒材轧制尺寸精度和性能预报准确程度的大幅度提高,对棒材的精确计数要求也越来越高。在线棒材计数系统包括计数系统和打捆系统,后者主要是精确分离棒材。对此,在论述该系统理论研究和应用现状的基础上,提出一种新的计数方案,以解决在线棒材的计数问题。     

棒材计数装置的研究

通过对棒材成品输送过程中运动规律的分析,针对一种棒材自动检测计数新方法,及其相应的机电一体化装置进行了研究,该装置采用机械和光电巧妙结合的方法,解决了棒材不规则排列对棒材计数的影响,实现了对棒材稳定、准确的自动计教与拉制。     

无牌坊式十一辊棒材矫直设备

成品棒材通过运料辊道、剪切、冷却、移送等各道工序,往往使棒材产生弯曲,造成废品。矫直机能使弯曲的棒材产生适量的弹塑性变形,以此消除弯曲而得到平直的棒材,提高棒材的合格率,提高经济效益。     

Use of the BendMeister rod bender for occipitocervical fusion: technical note

The creation of various curves in bendable metallic rods remains difficult. We describe a simple instrument that uses two bending levers to provide the mechanical advantage required to easily shape up to 5.5 mm diameter bendable metallic rods with precision, control, and minimal nicking or scratching of the metal surface. We have successfully used this tool to contour primary and secondary curvatures in threaded Steinmann pins and grooved titanium rods for occipitocervical fusion.     

钢水连续测温的新方法

实验证明将两种不同材质的金属陶瓷棒作为测温热电偶的两极，置于液态金属中连续测量金属温度，其原理和方法是可行的。金属陶瓷棒组成的新型热电偶耐渣侵蚀性好，耐热震性强，输出热电动势值较大，在金属熔化温度范围内其热电动势与温度呈明显的线性关系，为高温液态金属的温度测量提供了一种新方法。     

WC/Co复合粉制备超细晶挤压圆棒工艺之研究

采用水溶液化学法制备的纳米复合粉作原料,研究制备超细晶挤压圆棒的生产工艺。含钴12%（质量分数）的WC/Co纳米复合粉中加入适量的复合抑制剂,经湿磨、挤压成型、加压烧结后检测其合金特性值,通过对比不同湿磨时间和烧结温度条件下的合金性能,研究复合粉生产挤压圆棒的工艺参数,研究结果表明：复合粉可应用挤压成型工艺生产出高性能的圆棒。钴12%合金圆棒的硬度可达92.8RA以上,抗弯强度达4 200MPa,碳化钨晶粒度小于0.4μm。     

GB/T701-1997低碳钢热轧圆盘条标准研究

针对GB/T 70 1标准成分、性能、为冶炼方法等相关问题进行探讨 ,建议拉丝用盘条应另立标准 ,并就此提出一些看法     

High Temperature Electric Conductivity of Pure Silicon

Abstract

The electric conductivity of high purity silicon has been measured at elevated temperatures. Thin silicon rods were heated in a horizontal electric resistance furnace up to temperatures of 1120 °C. By passing a current through the rods and by measuring the resulting voltage drop, the conductivity was determined in the temperature range from 550 to 1120 °C. The data compare very well with reported literature values.     

Carbide rods with helical twisted coolant holes

The production of carbide rods with helical twisted coolant holes is made less expensive thanks to new production processes says Konrad Friedrichs KG. The use of a continuous twisting process with simple spiral nozzles allows increased automation. The development of new plastifying agents makes it possible to produce carbide rods with diameters of up to 33 mm using extrusion presses. The optoelectronic monitoring and control of the new production process ensures the quality requirements placed on carbide rods with helical twisted coolant holes with regard to various carbide grades.     

六西格玛管理在高碳钢小方坯连铸中的应用

针对鞍钢股份有限公司炼钢总厂二分厂高碳硬线钢铸坯废品率高的问题,采用六西格玛管理的方法分析了工艺技术、设备和基础管理几方面存在的问题,通过控制中间包钢水过热度、二冷水比水量、稳定拉速并控制电磁搅拌频率和电流,高碳硬线钢铸坯的废品率降至0.12%以下。     

Ultrastructure of the rat periodontal ligament as observed with quick-freeze, deep-etch and replica methods: arrangement of collagen and related structures

The ultrastructure of the periodontal ligament of rat molars was examined with the quick-freeze, deep-etch replica methods. It was mainly composed of elongated fibroblast-like cells and 40- to 50-nm-wide collagen fibrils that are arranged parallel to one another to form fibers approximately 1 micron in width. Collagen fibrils are composed of 10-nm-wide substructures that may run helically against the long axis of the fibril. Numerous rod-like structures ('rods') approximately 10 nm in width are present around the collagen fibrils. Individual or groups of rods span spaces between neighboring collagen fibrils to interconnect them. The surfaces of the fibroblast-like cells are also connected to the nearest collagen fibrils through the rods. In place, strands with a thickness similar to that of the rods were seen self-assembled into irregular meshwork structures. The treatment of the tissue with 10% sodium hydroxide for up to 5 days removed most of these rods and strands, thus exposing a three-dimensional arrangement of collagen fibrils that is often not fully visualized in untreated tissues. With histochemical staining of thinly sectioned tissues using Alcian blue, these rods and strands were positively stained, and thus they were demonstrated to be composed of proteoglycans. The ultrastructural arrangement of the periodontal ligament, observed in this study as a delicate interaction of collagen and proteoglycan components, is likely to play a significant role in the transmission of occlusal forces applied to the tissue and in the dissipation of mechanical shock.     

Bond to Concrete of FRP Rebars after Cyclic Loading

The bond mechanism of fiber-reinforced polymer (FRP) rebars to concrete was studied to evaluate the effect of cyclic loading. Five different types of 12.0- and 12.7-mm rebars were tested. The FRP rods were embedded in concrete blocks and were subjected to up to 450,000 cycles at service stress level. The loading was accompanied by immersion in water at 60 and 20°C to accelerate deterioration effects. Pullout behavior of the rods was determined at the end of the loading period. The results indicated a reduction in the bond strength after loading. Three mechanisms of failure were identified: (1) Abrasion of the surface of the rod, which, in the case of uniform resin throughout the rod, may lead to a reduction of 20–30% in the bond strength; (2) delamination of the outer layer of the resin at the surface of the rod, which may lead to a reduction of up to 60% in the bond strength; and (3) abrasion of cement particles entrapped between the rod and the concrete, which serves as the main source of “bond” for smooth rods leading to approximately 70% of reduction in the bond strength. There was no significant change in the effect of curing temperature on the loss of bond.     

钢材打捆机盖轮系统功能的理论分析与实验验证

现代的钢材打捆机均装备有盖轮系统 ,抽线时盖轮顺次张开能使捆线以更大的力捆紧钢材捆。从理论上对盖轮系统的功能进行了分析 ,并作了实验验证。