CSP板卷边部缺陷的研究

针对涟钢CSP板卷存在的主要质量问题--板卷边部缺陷,统计分析大生产数据,现场跟踪试验,以及实验室验证,研究查找出CSP板卷边部缺陷的主要影响因素,通过采取相应控制与改善措施,获得了良好效果.     

CSP板卷边部缺陷的研究

针对CSP板卷存在的主要质量问题——板卷边部缺陷，统计分析大生产数据，现场跟踪试验，以及实验室验证，研究查找出CSP板卷边部缺陷的主要影响因素，通过采取相应控制与改善措施，获得了良好效果。     

酒钢CSP热轧钢带边损的相关因素分析

针对酒钢CSP钢带存在边部缺损质量问题,运用统计技术对生产数据统计对比,通过现场跟踪试验以及实验验证:查找出CSP板卷边部缺陷的主要影响因素,并通过采取相应的控制与改善措施,从逐年趋势图对比看,其边损率显著降低,获得良好效果。     

CSP板卷边部裂纹影响因素分析

 对钢中碳含量、Ca/Als、拉速、结晶器振动及二冷制度等工艺因素进行了综合分析，并从理论上对钢中氮含量、钢中铝含量及AlN质点析出等方面进行了阐述，指出了影响CSP板卷边部裂纹的主要因素是结晶器振动和二冷制度，为生产实践中减少CSP板卷边部裂纹发生指明了方向。     

酒钢CSP热CLN带边损的相关因素分析

针对酒钢CSP钢带存在边部缺损质量问题，运用统计技术对生产数据统计对比，通过现场跟踪试验以及实验验证：查找出CSP板卷边部缺陷的主要影响因素，并通过采取相应的控制与改善措施，从逐年趋势图对比看，其边损率显著降低，获得良好效果。     

CSP热轧板卷边部裂纹成因及控制

为了抑制CSP热轧板卷边部裂纹,对CSP热轧板卷边部裂纹的成因进行了研究.CSP热轧板卷边部裂纹缺陷主要有3类:边部横裂纹、边部纵裂纹、边部烂边或掉块等.板卷产生边部裂纹的主要原因是:连铸坯表面边部横裂纹(包括深的振痕)和边部的细小纵裂纹,在加热和轧制过程中不断扩展;钢液在凝固以及铸坯在冷却、均热、轧制、层流冷却和卷取等过程中的热应力、机械应力以及相变应力等作用力超过钢的塑性变形抗力.抑制CSP热轧板卷产生边部裂纹的主要措施是:控制好合适的钢水成分;制定有效的工艺参数,如结晶器热流密度、结晶器振动参数、二冷冷却强度等.工业试验结果表明,CSP热轧板卷边部裂纹率由7.93%降低到1.81%.     

主要精炼工艺参数对边裂的影响分析

薄板坯连铸连轧是世界上最先进的板材生产线，其对精炼炉所提供的钢水有严格的质量要求。成分和温度合适及纯净的优质钢水是CSP顺利生产和生产优质板卷的基本保证，是生产无边裂，无烂边，以及没有各种内部缺陷并且符合性能要求的优质板卷的基础。     

300系不锈钢退火酸洗黑边缺陷分析

不锈钢酸洗板卷以优质的热轧板卷为原料,经过连续退火和酸洗去除氧化皮,表面形成钝化膜,成为表面质量好、机械性能优的冷轧原料.本文主要针对酸洗后板卷黑边缺陷,对钢卷黑边进行微观分析,结果表明钢带边部发黑主要为Fe/Cr氧化物,通过增加退火酸洗产线的抛丸机侧抛设备和高压水冲洗边部装置,黑边缺陷发生率降至1％以内,本文对热酸线和冷酸线的生产具有参考意义.     

CSP热轧SPHC板卷氧化皮厚度分布

研究了CSP热轧SPHC单张板和板卷的氧化皮厚度，并与传统热连轧产品进行了比较。研究发现，从CSP板卷宽度中心至边部氧化皮厚度逐渐增加，且中心到1／4宽处的增加趋势比1／4宽到边部的强；单张板的氧化皮比板卷的厚；下表面的氧化皮比上表面的厚；CSP板卷厚度（h）与氧化皮厚度（x）间呈x=3．95695＋2．09607h关系，而传统热连轧产品则呈x=8．152＋3．132h；CSP板卷的氧化皮较传统热连轧的薄，其厚度对板厚也不太敏感。应以板卷下表面的氧化皮性状作为制定酸洗工艺的基础。     

热轧板卷边裂成因浅析及控制

采用金相显微镜、扫描电镜并结合工艺调查,对某厂热轧板卷边裂缺陷成因进行了研究分析.结果表明:冶炼脱氧不良、浇注异常是造成烂边边裂缺陷的主要原因;铸坯待轧时过热过烧是造成翘边边裂缺陷的主要原因.根据研究结果对生产工艺进行了优化,取得了较好的效果,板坯边裂缺陷率由80～85炉/月降至4～5炉/月,板卷"烂边"缺陷基本消除,"翘边"缺陷率由17.6%降至1.2%.     

对多孔物质或固体粉末比表面积测定方法探讨

本文对氮吸附法测定多孔物质及固体粉末比表面积进行了探讨。实验结果表明样品检测精密度明显提高。     

A simplified screening test for identifying people with low vision in developing countries

Simple but effective tests have been produced for screening subjects with low vision in developing countries. These tests of distance and near vision, based on the E test, were evaluated and validated in trials with people aged 4-90 years, and have been field tested in the health, education and rehabilitation services in 32 developing countries. Their sensitivity and specificity as screening tools for low vision have been calculated; sensitivity of 85% and specificity of 96% for the distance vision test, and sensitivity of 100% and specificity of 84% for the near vision test. The content and format of the tests have been demonstrated to be appropriate for developing countries, and their effectiveness for screening for low vision has been confirmed.     

ICP-AES法测定低铬、中铬合金中Si、P、Mn的含量

利用全谱直读分析技术,通过对试样溶解方法、试验仪器、分析参数等因素进行研究,综合确定了最佳试验条件.实验结果表明,该方法测定低铬、中铬合金中的Si、P、Mn,其分析误差符合冶金类合金中的误差要求,可用于普通材质的检验.     

Experimental Studies on Supersonic Cold Flow Mixing with Ramp Mixers

The mixing field in a supersonic cold flow past a set of compression–expansion ramps mounted at the downstream end of a strut, with staged injection at two tandem locations on the strut upstream of the ramps, has been experimentally investigated. Air and helium have been used to inject into a primary stream of air at an inlet Mach number of 2.0. Two test section geometries, one having a flow cross section twice that of the other, have been considered. The larger test section has wall struts as well as a middle strut, whereas the smaller one has the strut only in the middle. Terminal bulk pressure and wall static pressure measurements, and Schlieren visualization have been performed. The Mie scattering technique has been used to obtain the concentration contours of the injectant across the flow cross section at several axial locations downstream of the injection points. The results indicate better mixing with helium injection and less influence of the boundary layer along the test section walls with the larger test section, as expected.     

致密型MoB-CoCr涂层在钢铁工业中滚镀锌生产线中的应用

MoB/CoCr涂层具有较高的耐熔融锌侵蚀的能力,并被广泛地应用于钢铁工业镀锌生产线中[1].然而在实验室测试中,这种涂层有时还没有显示出其原有特性就失效了.研究发现,这些失效的试样往往具有较高的孔隙率,导致了熔融Zn通过孔洞加速渗透对基体钢材产生腐蚀并使涂层脱离.这表明,在实际应用中,高密度涂层对于展现其耐蚀性与保证质量的极度重要性.在本文中,我们通过优化粉末性能并采用JP-5000超音速火焰喷涂制备了高密度MoB/CoCr涂层.我们通过盐雾试验来评估涂层的致密性.最佳密度的涂层在经过300小时的盐雾试验后,其低碳钢基体材料没有发生锈蚀.另一方面,多孔的涂层在经过24～48小时的盐雾试验后,其基体材料出现了锈蚀.经盐雾试验验证的最佳涂层在工业镀锌浴中浸没90天后（＞2000小时）没有发生失效.     

A numerical and experimental study of deformation characteristics of the plane strain punch stretching test

Recently, a simple new test method called the plane strain stretching (PSS) test has been developed to evaluate the stamping formability of sheet materials. The PSS test has been proven to have good reproducibility and show good correlation with press performance. In order to clarify the deformation characteristics of the PSS test and investigate the effect of material and process variables on the performance of the PSS test, three-dimensional finite element simulations for the PSS test were performed and the results compared with experiments.     

The effect of inertia on tensile ductility

One-dimensional numerical simulations of dynamic tensile tests have been carried out over a wide range of test velocities for materials having aHollomon-type constitutive law with power-law strain-rate sensitivity. A variety of values of the strain-hardening exponent and strain-rate-sensitivity index have been used to analyze the effect of inertia on tensile ductility. Results show that the total elongation of the specimen is enhanced by inertia at high test velocities. This inertial effect varies with the strain-hardening exponent and strain-rate-sensitivity index and can be scaled with the normalized material density and the test velocity. Based on these results, the critical test velocity for the onset of the inertial effect as a function of material parameters has been numerically determined. To account for the effect of inertia on the enhancement of tensile ductility, a simple phenomenological explanation has been proposed.     

Colorectal cancer and hemoccult

Hemoccult slides have been used in an attempt to determine their usefulness as a screening method for the detection of colorectal neoplasia. Two methods have been used. In the first, 300 unprepared patients had an immediate single-stool specimen tested with Hemoccult. Only nine patients were referred for investigation after this single test, and no case of colorectal neoplasia was discovered. In the second method over 2,500 three-stool test kits were distributed to the public, of which 1,160 (46%) have been returned and tested. Positive tests were obtained in 68 patients. Follow-up of 58 of these patients has led to the detection of three cases of carcinoma of the colon and nine cases of benign polyps greater than one centimetre in diameter. The cost of screening patients with a three-stool test has been calculated to be $2.50 per patient.     

光谱分析钢中酸溶铝方法的研究与应用

介绍了在光谱仪上用PDA(脉冲分布分析法)方法测定钢中酸溶铝的原理与优点. 通过试验,确定出最佳分析参数,得出钢中Als(酸溶铝)的光电光谱PDA分析方法,与化学分析法对比,该方法准确可靠.