道岔轨断裂原因分析

PD3在线热处理钢轨制作道岔轨时,部分钢轨在弯曲过程中发生冷弯断裂。采用电子显微镜、光学显微镜、计算机仿真模拟分析等方法,对断裂钢轨进行了分析。结果表明,钢轨在冷加工过程中应变过大,导致钢轨断裂;操作不当、顶进力和支点间距等多因素的影响也是造成钢轨在冷弯加工过程中断裂的另一原因。     

20号优质碳素结构钢板冷弯性能不合格原因分析

采用金相组织检验、化学分析、扫描电镜微观分析及能谱分析对20号优质碳素结构钢板冷弯断裂的试样进行了检测和分析。结果表明,钢板中有较多的非金属夹杂物及轧后冷却速度过快和冷速不均匀是导致冷弯性能不合格的主要原因。提出了相应的改进措施。     

大截面直流铜母线制作安装技术创新做法

金隆20万吨电解车间直流母线使用6×TMY-300×20铜母线，铜母线截面积和单位载流量在国内铜电解行业具有一定的先进性和代表性，我单位针对铜母线的制作和安装，进行了充分的准备，并对传统工艺进行了改进，保证了工期和质量。     

薄钢板的冷弯成型

分析了薄板的物理性能及冷弯成型的性能,并依据防盗门、防火门型材的冷弯成型生产中产生的冷弯裂纹、边部波浪、袋形波、纵向弯曲、角部皱褶、扭曲等冷弯缺陷,提出了相应的工艺改进措施.     

20钢板冷弯成型开裂分析

8mm厚的20钢板在冷弯成型时开裂,呈木纹状断口.经冷弯试验,电镜分析和金相分析发现钢板纵向冷弯完好,横向冷弯开裂,开裂原因为板材中存在带状偏析和硫化锰夹杂所致.     

输变电设备用铜铝复合母线研究现状与发展

阐述了输变电设备用铜铝复合母线的发展历史,详细介绍了输变电设备用铜铝复合母线的生产工艺技术、性能、温升计算方法以及行业发展趋势,以期为铜铝复合母线研究人员提供参考与借鉴。     

非180°冷弯试验的自动控制

金属的冷弯试验是检验金属材料承受规定弯曲程度的变形能力,并显示其缺陷。GB232—88《金属弯曲试验方法》标准及一些产品标准,对冷弯试验时的试验机加载速度、试样尺寸、支辊间的距离、弯心辊直径等都作了说明。GB232—88标准在试验程序中规定:试样弯曲到规定的弯曲角度或出现裂纹、裂缝或裂断为止GB712—88《船体用结构钢》中力学性能规定:B级船板宽冷弯弯曲角度为120°、GB3277—91《花纹钢板》对冷弯角度规定为90°。以上都没有规定测定冷弯角度的方法,也没有规定测量精度。这样,在实际试验中会遇到一些麻烦。特别是非180°冷弯试验,如果实际弯曲角度已接近规定角度,且没有缺陷,产品是否一定合格?如果超过规定冷弯角度出现了裂纹,那么在规定角度上是否还会出现裂纹呢?无法判定。 冷弯试验大多数仍在试验室的万能材料试验机上进行,使用样板与实际冷弯角度做对比。冷弯试验时,当试样弯曲角度与样板角度相吻合。再停机、卸荷。由于观测者与操作者的配合及其它原因,弯曲角度的偶然误差比较大。经统计,我们试验室B级船板120°冷弯试样,弯曲角度误差范围一般在-7°～+5°之间。     

提高冷弯型钢加工质量的探讨

随着社会需求的增多以及国家对钢材质量要求的提高,冷弯型钢设备加工精度的技术也要得到较大的提升。通过对国内外冷弯型钢生产技术的发展的分析与展望,从产品的应用、设备的改造、吸收先进技术等方面,提出了提高冷弯型钢加工精度的技术研究的几种思路,指出在提高冷弯型钢设备加工精度技术的过程中,应建立全新的技术体系,优化技术应用方案。     

SS400钢卷冷弯不合格原因分析

通过宏观检验、力学性能测试、化学成分分析和金相检验对SS400钢卷冷弯不合格的原因进行了分析。结果表明:钢板中氧化铝夹杂偏多是冷弯试样出现裂纹的主要原因,同时提出了减少冷弯裂纹出现的措施。     

组合截面冷弯薄壁型钢结构研究进展

冷弯薄壁型钢房屋抗震性能优越,适合工业化建造,在国内外建筑行业已占有一席之地,符合国家“十三五”规划对房屋建筑发展提出的新要求。该文对国内外在冷弯薄壁型钢房屋受力性能的研究成果和相关规范的设计规定进行了全面的综述,发现传统冷弯薄壁型钢房屋在传力机制、受力构件截面种类等方面的不足,提出新型组合截面的冷弯薄壁型钢“非盒子”式的框架结构体系,总结该体系中受力构件、节点以及整体框架受力性能的研究进展,给出了组合柱稳定承载力、节点极限弯矩和初始刚度的计算公式。最后对该类组合截面冷弯薄壁型钢框架结构体系今后需要深入研究的问题提出了建议。     

The effect of cyclic bending on the mechanical properties and dislocation structures of drawn steel bars

Axisymmetric bar drawing increases the strength and decreases the ductility of metals. The recovery of these final mechanical properties often employs costly annealing processes. This paper discusses the possibility of controlling the mechanical properties of AISI 1010 steel bars through cyclic bending after one or two drawing passes and between these two successive passes. It is shown that cyclic bending softens the drawn material and increases its uniform elongation. The attending dislocation structures are presented and related to the associated mechanical properties. It is considered that cyclic bending is of interest in the industrial control of the final mechanical properties of drawn AISI 1010 steel bars.     

Structural properties of Cu(In,Ga)Se2 thin films prepared from chemically processed precursor layers

We have developed a chemical process for incorporating copper into indium gallium selenide layers with the goal of creating a precursor structure for the formation of copper indium gallium diselenide (CIGS) photovoltaic absorbers. Stylus profilometry, EDX, Raman spectroscopy, XRD and SIMS measurements show that when indium gallium selenide layers are immersed in a hot copper chloride solution, copper is incorporated as copper selenide with no increase in the thickness of the layers. Further measurements show that annealing this precursor structure in the presence of selenium results in the formation of CIGS and that the supply of selenium during the annealing process has a strong effect on the morphology and preferred orientation of these layers. When the supply of Se during annealing begins only once the substrate temperature reaches ≈ 400 °C, the resulting CIGS layers are smoother and have more pronounced preferred orientation than when Se is supplied throughout the entire annealing process.     

Bending behavior of as-cast and annealed ZrCuNiAl bulk metallic glass

Here ZrCuNiAl bulk metallic glass samples were annealed below its glass transition temperature. The bending behaviors and thermal properties of the as-cast and the annealed samples were studied. The increase of annealing time leads to the transition from ductile to more brittle behavior during bending tests. Meanwhile, prolonging the annealing causes a gradual decrease in the free volume content. Based on free volume theory, the change in the microstructure and mechanical properties induced by annealing treatment has been interpreted in detail.     

40Cr磨光材端面及心部缺陷分析

某钢铁厂生产的40Cr磨光材在退火矫直车皮后的成品检查时发现,部分磨光材端面存在严重向内凹陷并伴有心部孔洞的缺陷。采用低倍检验、金相检验、扫描电镜观察和能谱分析等方法对缺陷形成的原因进行了分析。结果表明:40Cr磨光材端面及心部缺陷是在退火后的矫直过程中产生的,是由于受到了棒材内部的拉应力作用而形成的;同时试样轴向中心处的夹杂物细长且相对集中,也有可能成为产生心部孔洞的诱因。     

Annealing and diffusion processes in thin film CdS/Cu2S solar cells

Diffusion of copper during post-fabrication annealing of CdS/Cu₂S thin film solar cells was studied by Auger electron spectroscopy. Depth profiles of the constituent element concentrations indicate that, for samples annealed in air, a deep penetration of copper into the cadmium sulphide layer occurs together with a significant out-diffusion of cadmium. In contrast, the copper penetration which results from vacuum or hydrogen annealing treatment is substantially less and no out-diffusion of cadmium is observed for annealing temperatures up to 400°C.     

一种新型的空调连接管——Hylife合金管

本文介绍了一种新材料空调连接管路—Hylife合金管,并将其与铜管在材料本身以及安装使用性能等方面做了分析及实验对比。实验结果表明,经过合金成分优化,原材料特殊均质化以及在线退火晶粒细化等工艺生产出的Hylife合金管轻、热保持性好且抵抗腐蚀能力强;在操作上,Hylife合金管表现出比铜管更优良的弯曲和扩口性能,耐压超过14 Mpa,可满足空调室内连接管的耐压要求。另外,相比铜管,Hylife合金管更具经济性。     

Effect of carboxylic acid on sintering of inkjet-printed copper nanoparticulate films

The reduction effect of various carboxylic acids on inkjet-printed copper film was investigated. Carboxylic acids were exposed to the film by nitrogen gas that was bubbled through the liquid acids during the annealing process. It was observed that in the case of saturated monocarboxylic acid (formic, acetic, propionic, butyric), the acids with shorter hydrocarbon chains perform better in reducing the surface copper oxides in the printed copper conductive film. The printed films exposed to formic acid vapor exhibited the lowest resistivity (3.10 and 2.30 μΩ cm when annealed at 200 and 250 °C, respectively). In addition, the oxalic acid more effectively reduces copper oxide than formic acid and its usage can shorten the annealing time for highly conductive printed copper film. This reductive annealing process allows fabrication of copper patterns with low resistivity, (3.82 μΩ cm annealed at 250 °C) comparable to the resistivity of bulk copper.     

Strain energy release rates for a straight-fronted edge crack in a circular bar subject to bending

The strain energy release rate for a straight-fronted edge crack in a bar of circular cross section subjected to pure bending is determined. The cracked bar is modelled with two-dimensional plane-stress finite elements and strain energy release rates, determined from this model, are shown to be in close agreement with existing results for a bar subjected to three-point bending in which strain energy release rates were determined by measuring the compliance of the bar experimentally. The strain energy release rates for a crack in the circular cross section bar are found to be lower than those in a rectangular cross section bar having the same relative crack length and subjected to the same bending moment. Previously determined results for uniform tension are superimposed to obtain strain energy release rates for a circular cross section bar which is subjected simultaneously to a tensile load and a bending moment.     

钢筋混凝土立柱爆破后钢筋骨架承载特征研究

钢筋混凝土立柱爆破后通常会残留钢筋骨架,钢筋骨架的承载特性是判断结构局部失稳的重要前提,同时也是确定立柱爆破高度的理论依据。基于立柱爆后实际形态,开展了具有初弯曲形态的立柱钢筋骨架缩尺模型试验,模拟了顶部有水平向约束和无水平向约束两种工况。试验结果表明:立柱钢筋骨架的承载力随着其高度和初始挠度的增加而显著降低;顶部无水平约束钢筋骨架的失稳形态主要表现为侧向倾斜,顶部有水平约束钢筋骨架的失稳形态主要表现为竖向压缩和钢筋外凸。模型试验实测承载力远低于欧拉等直压杆模型计算值,而高于初弯曲压杆模型计算结果,且实测值与初弯曲压杆模型计算值存在线性关系。根据试验结果,给出了初弯曲压杆失稳模型的修正建议。     

TC11钛合金棒开裂原因分析

TC11合金钛棒在退火后发现裂纹。为分析裂纹产生的原因,对其进行了裂纹宏观和微观检验、显微硬度测试和能谱分析。结果表明：原材料在冶炼过程中氧、碳含量偏高聚集在材料中形成偏析,在轧制过程中开裂,退火后发现的钛棒纵表面的裂纹是由原材料带来的。