盐酸机组的拉伸弯曲矫直机浅析

热轧带钢在冷轧前既需要进行酸洗以去除带钢表面的氧化的皮，也需要良好的板形。在酸洗前增加拉伸弯曲矫直机，带钢经过反复弯曲以及表面压缩和延伸，可使其表面氧化铁皮产生裂纹甚至破裂，为酸洗液清洗掉氧化铁皮提供了良好的界面，易物彻底清除带钢表面氧化铁皮。而在弯曲矫直的同时，对带钢施加一定的张力，在张力和反复弯曲矫直的作用下，带钢产生永久的延伸变形，从而改善了带钢板形。     

轧件宽度对热轧带钢轧机弹跳的影响

 轧机的弹跳方程是AGC控制系统不可缺少的模型,但轧制过程中轧机的实际弹跳与轧件的宽度有关,当轧件宽度显著偏离全辊面宽度时,轧机的弹跳也会严重偏离预压靠方法得到的结果。采用影响函数法分析了轧件宽度对轧机弹跳的影响,计算结果表明随着轧件宽度的减小,轧机弹跳宽度补偿量增加;随着轧制力的增加,轧机弹跳宽度补偿量增加。根据影响函数法计算结果,建立便于工程应用的轧机弹跳宽度补偿回归模型。     

板厚对冷弯成型过程及回弹影响的有限元模拟

采用ANSYS／LS-DYNA有限元软件的显式求解功能对厚度分别为4mm、5mm、6mm、7mm、8mm的板料进行有限元弹塑性分析，得到板料成型过程中厚度因素对轧件应力、应变的影响规律。接着利用ANSYS的隐式求解功能分析厚度因素对板料回弹的影响规律，并将回弹量的模拟数值与工作现场的回弹数值进行比较，表明计算结果具有一定的可信度。     

余热处理钢筋冷、反弯裂纹及消除措施的研究

针对应用轧后余热处理工艺生产的大规格英标钢筋所存在的冷弯和反弯裂纹问题作了较为系统的研究，并根据研究结果，提出了明确可行的技术措施和工艺改进方案。     

新型汽车用高强度钢的应用现状与发展趋势

对先进的高强度钢及其在汽车工业中的应用进行了评述,详细介绍了几种高强度钢,如烘烤硬化钢、双相钢、相变诱发塑性钢等的原理、成分、性能特点以及目前的应用现状与开发进展状况.简述了高强度钢板在成形中所遇到的延伸凸缘性和弯曲成形性有所降低、回弹和弯曲开裂现象增多等问题,指出应把高强度钢板研究与对应的成形应用技术研究结合起来.还简述了国内外在高强度钢板上的研究方向,即在进一步提高强度、降低车重的同时,综合考虑安全、成形等因素,通过更多的新的强化机制来提高强韧性.     

Energy Method in Stretch Reducing Process of Steel Tube

According to the theories for stretch reducing process and steel tube plastic deformation, the energy method was used to mesh the rolled deformation zone of the steel tube into the upper limit elements, and an admissible velocity field was constructed to deduce a series of formulas of the inner virtual power consumption of deformed bodies. The roiling force during the stretch reducing process could be obtained by optimizing the upper limit power, which could provide guidelines for a proper choice of the stretch reducing process and devices for steel tube companies, as well as new products and devices.     

Q195盘条多颈缩现象原因分析及消除

针对Q195线材在拉伸过程中出现的多颈缩导致断后伸长率偏低的现象进行了分析,结果表明混晶和夹杂物是引起Q195线材断后伸长率偏低的主要原因,并根据分析结果提出了相应的改进措施。     

张力减径钢管质量缺陷及预防

张力减径是热轧无缝钢管生产中不可缺少的一道轧制工序,钢管在经过减径机后容易出现一些质量缺陷.文章详细介绍了钢管在张力减径后容易产生质量缺陷及其形成原因和预防.     

Histological study of the tracheal adventitia, perichondrium and annular ligament

The trachea begins at the lower border of the cricoid cartilage and passes down to bifurcate into the left and right mainstem bronchi. The presence of tracheal invasion is crucial factor influencing the prognosis for patients with cancers of the thyroid gland, hypopharynx, esophagus, etc. In order to understand the manner of invasion of the above tumors, precise knowledge of the normal tracheal structure is indispensable. This study was undertaken to clarify the normal microscopic structure of the trachea. Five normal tracheal specimens obtained at surgery were examined histologically and immunohistochemically. The loose connective tissue around the trachea, known as adventitia, was divided into a loose outer and a dense inner layer by hematoxylin and eosin (HE) staining. This two-layer pattern was clearly seen near the annular ligament but was obscured away from it. The connective tissue of the inner layer ran obliquely to joint the connective tissue of the annular ligament and ended in the submucosal layer. This arrangement of connective fibers seems to play a role in allowing the trachea to stretch and bend. Tracheal cartilage is covered with a dense fibrous membrane known as the perichoundrium. Between the superficial fibrous membrane and mature cartilage cells lies zone of immature cartilage made up of oval or spindle cells, and the inclusion of this zone in the perichondrium has long been a subject of controversy. In our study, the zone was homogeneously stained red by the elastica van Gieson's stain and was clearly distinguished from other structures. Immunohistochemical staining revealed a wide distribution of type I and type III collagen on the fibrous membrane and the zone of immature cartilage cells, while mature cartilage cells did not show such collagen. Based on these findings, we conclude that the zone of immature cartilage cells belongs to the periochondrium, which thus contains two layers, an outer fibrous layer and an inner transitional layer of immature cartilage cells. Our conclusions are as follows: 1. Tracheal adventitia is divided into two layers, an outer loose and an inner dense fibrous layer. 2. Tracheal perichondrium also consists of two layers, an outer fibrous layer and an inner transitional layer. 3. The fibrous bundle originating from the adventitia joins the connective tissue of the annular ligament, probably in order to allow the trachea to stretch and bend.     

Supercritical Flow in Bend Manhole

Supercritical flow in a bend manhole for combined sewer systems is considered for a typical relative curvature and deflection angles of 45° and 90°. The typical features of bend flow in a U-shaped channel are determined, including the surface profiles along the inner and the outer bend walls, impact flow at the manhole outlet into the downstream sewer pipe, air entrainment characteristics, and wave development in the downstream sewer. Also, typical velocity distributions along the manhole are presented, and the capacity of the conventional bend structure is determined. To increase the discharge capacity across a bend manhole, the so-called bend cover is introduced. This cover element finished in steel can be removed for maintenance and inspection purposes. It limits the wave height close to the bend outlet to 90% of the sewer diameter and allows air entrainment into the downstream sewer. The performance and capacity of bend flow may significantly be increased, and the novel element may easily be added to existing manholes.     

钼镧合金板材高温抗载荷弯曲性能研究

通过轧制和热处理工艺制备出了两种不同组织的钼镧合金板材,研究了该板材在1700oC和1800℃高温条件下的抗载荷弯曲性能。结果表明：采用常规工艺轧制和退火后生产的钼镧合金板材组织细小均匀,采用大变形量加工并提高温度进行完全再结晶退火后生产的钼镧合金板材形成了一种粗大的、燕尾搭接的再结晶组织;在1700—1800℃高温和相同载荷条件下测试时,粗大晶粒的钼镧合金板材具有优异的抗弯曲性能,其最大弯曲值小于常规热轧板材最大弯曲值的20％。     

Experimental Analysis and Prediction of Springback in V-bending Process of High-Tensile Strength Steels

Experimental setup has been designed, to study the effects of thickness, width, bend angle and machine tool parameters on the springback, in two high-tensile strength steel grades, namely JSC440 and JSC590, during the V-bending process. Relationship between the springback and the parameters are analyzed using plots. Optimal combination of parameters for the minimum springback is evaluated. Analysis of variance has been carried out to analyze the magnitude of influence of these parameters on the springback. Using the experimental results, analytical models for the prediction of springback for the combinations of blank thickness, width, bend angle and machine tool parameters have been developed. Results reveal that in V-bending of JSC440, thickness and width are the dominant factors influencing the springback, whereas in JSC590 steel, insignificant change in springback is observed with the change in width of blank and using the hydraulic press with holding. However, thickness of steel sheet and bend angle influence significantly the springback in JSC590 steels.

     

Stretch Bending of Aluminum Extrusions: Effect of Geometry and Alloy

An experimental stretch bending study is presented in this paper. A total of 24 tests on 2-m-long rectangular hollow section aluminum specimens are performed in a specially designed stretch bending rig. All tests are carried out with a constant tensile force corresponding to the material's yield stress. Factorial analysis is systematically used in the planning of the experimental program as well as in the result interpretation. Special attention is paid to the influence of the alloy, die radius, and specimen wall thickness on certain response parameters. As stretch bending is an important industrial forming process, die force, sagging, and springback are considered to be the most relevant responses. The tests show that the alloy has the largest influence on the die force and springback, while the sagging behavior is primarily controlled by the geometric parameters (i.e., die radius and thickness).     

Method for Improving Transverse Wall Thickness Precision of Seamless Steel Tube Based on Tube Rotation

The tube rotation method(TRM) refers to the rotational movement of steel tube about its axis as well as translation in rolling direction in stretch reducing rolling process.The influence of the TRM on transverse wall thickness precision of seamless steel tube was studied.Thickness distribution of the TRM was obtained by superimposing the thickened amount of single pass rolling.Results show that the TRM can effectively improve the evenness of thickness distribution.In order to analyze the influence mechanism of the TRM,the finite element method was adopted to simulate the thickness distribution in stretch reduction process.Results show that the TRM changes the roundtrip flow between two fix places of conventional stretch reducing and inhibits the directional accumulation of metal.In addition,the TRM has a correction effect on thickness cusp.All these advantages of the TRM help to improve the transverse wall thickness precision of seamless steel tube.     

7475铝合金大型锻件时效工艺研究

测定了7475铝合金双级时效及回归再时效（RRA）工艺状态下的常规拉伸性能和电导率，并通过标准三点弯和圆周切口圆柱试验测定各时效工艺的断裂韧性。从而研究双级时效和RRA工艺对常规力学性能，断裂韧性，电导率和微观组织的影响，结果发现回归再时效工艺并不适用于7475铝合金大型锻件的生产实践。     

连铸板坯热装炉对材性能的影响

分析比较了Ｑ２３５－Ａ碳结钢及Ｂ级一般强度船板钢连铸板坯红坯“裸送”热装炉与冷装炉轧制成材的板材工艺与力学性能，热装炉工艺成材的冷弯及冲击性能明显低于后者。     

轧制过程中宽展的原理及应用

轧制过程中，轧件不可避免的会出现压下、延伸和宽展变形。本文主要对宽展的原理及其在轧制工艺中的应用进行了阐述。     

板带轧制头部弯曲机理的研究

对板带轧制过程中产生的头部弯曲从理论上进行了研究。结果表明：简单对称轧制过程中轧件不会产生头部弯曲;对于异步轧制而言,轧制过程是轧件压缩、剪切和弯曲变形的复合变形过程,由于金属的流变状态和力学状态的不对称,全后滑产生的不均匀应力导致轧件头部易产生弯曲。     

热带钢精轧机板形在线设定系统设计

结合1450mm6机架热带钢连轧机板形在线设定系统软件，介绍了该系统的数据通信、多线程编程方法和数据处理等，并推导了弯辊力预设定模型及其补偿系数。通过对现场考核，并分析了系统投入前后大量实测结果的统计情况，证明了设定模型的有效性、数据通信的可靠性和多线程编程方式的优越性。     

G206H高风压钻具用球齿的开发与应用

针对G206高风压钻具用球齿开采坚硬岩层时易出现碎片的问题,通过调整原料中碳化钨粉的配方和改进生产工艺,开发出了一种牌号为G206H的高风压钻具用球齿,其耐磨性、抗弯强度等物理性能优良,在现场凿岩试验过程中未出现碎片状况。