高合金铁基烧结材料在轧钢导位中的应用研究

本文研究了高合金铁基烧结材料在轧钢导位中的应用。实验表明,通过粉末冶金液相烧结技术,可以获得具有优良综合性能的制品,材料密度ρ≥7.5 g/cm3,硬度≥55 HRC,抗弯强度≥1 000 MPa,冲击韧度αk≥3.9 J/cm2,满足了轧钢导位辊的工作要求。材料利用率可达95%以上、降低了制备成本。使用寿命是普通轧辊寿命的3~6倍,适用于线材和小型型材的轧钢生产。     

用高梯度磁场净化轧钢废水

通过用高梯度磁场处理热轧厂废水的试验,得到了在试验条件下浊度(水中不溶物的含量)和铁的去除率,确定了最佳净化条件.在此条件下,能够有效去除废水中的不溶物和铁,经过处理的水质达到了工艺循环水的水质标准.     

二次混合机改造

南钢烧结厂二次混合机通过降低筒体的仰角、提升筒体的转速,增加了混合料的混匀时间,提高了混合料的造球效率,介绍了设计中各种部件的选型和校核计算,该设备投产后大幅度提高了生产能力。     

一种用于强振环境的转速传感器

该文介绍一种简单、可靠、小巧的转速传感器。它的特点是在强振环境下仍具有很高的可靠,可用于坦克底盘、重型工程机械,燃气轮机组等机械作为转速监测。     

Linguistic Knowledge, Processing Speed, and Metacognitive Knowledge in First- and Second-Language Reading Comprehension: A Componential Analysis.

The authors report results of a study into the role of components of first-language (L1; Dutch) and second-language (L2; English) reading comprehension. Differences in the contributions of components of L1 and L2 reading comprehension are analyzed, in particular processing speed in L1 and L2. Findings indicate that regression weights of the L1 and L2 components are different. Although correlations between most processing speed components and reading comprehension are substantial, there are no unique contributions to the explanation of either L1 or L2 reading comprehension when linguistic and metacognitive knowledge are accounted for. In addition, L1 reading comprehension is shown to have a large contribution to L2 reading comprehension, supporting theories of L1-L2 transfer of reading skills. Results are discussed from a developmental perspective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phase Composition of Oxide Scales during Reheating in Hot Rolling of Low Carbon Steel

Low carbon steel was oxidized over the temperature range 1000‐1250°C in O₂‐CO₂‐H₂O‐N₂, O₂‐H₂O‐N₂, and O₂‐CO₂‐N₂ gas mixtures. Oxidation times were 12‐120 min. and the scales were 50‐2000 μm thick. The variations of these parameters were chosen to elucidate the phase composition of oxide scales under conditions similar to those of reheating furnaces in hot strip mills, using either thin slab casting or conventional casting and rolling technology. Two types of scales have been observed which are influenced by the furnace atmosphere, oxidation time, and temperature. The first type is a crystalline scale with an irregular outer surface, composed mostly of wustite (FeO), and a negligible amount of magnetite (Fe₃O₄). The second type is the classical three‐layer scale, composed of wustite (FeO), magnetite (Fe₃O₄), and hematite (Fe₂O₃). In general, the experiments showed that an increase in oxidation time decreased the percentage of wustite while the percentages of magnetite and hematite increased. A rise in oxygen concentration in the gas mixture increased the percentages of magnetite and hematite, confirming earlier experimental findings. In water vapour‐free atmospheres O₂‐CO₂‐N₂, the oxide scales had a low percentage of wustite, and high percentage of magnetite and hematite. Carbon dioxide showed a small influence at 1100°C, and a negligible one at 1250°C.     

Concast连铸机自控系统简介

天津钢铁有限公司引进了瑞士Concast公司6机6流方、圆坯连铸机及相关技术，文章简要介绍了Concast连铸机的自动控制系统的特点和功能。     

基于遗传算法的工作辊温度场参数优化模型

针对热连轧机工作辊热辊形计算中温度场模型的热交换等参数难以确定的问题 ,建立了基于遗传算法的参数优化模型 ,可以解决复杂条件下的热参数的求解问题。利用优化参数计算的轧辊温度场与实际测量结果一致。     

轧后穿水冷却工艺对棒材组织性能的影响

针对轧机产量提高后冷床冷却能力不足的问题 ,研制开发了棒材轧后穿水冷却技术。通过对小规格 2 0MnSiV热轧带肋钢筋进行轧后穿水冷却 ,钢材上冷床温度降低了 90～ 110℃ ,提高了产品质量 ,改善了各项力学性能 ,抗拉强度平均提高了 3 5～ 40MPa ,钢材性能合格率由 97.5 %提高到了 99.6% ,解决了冷床冷却能力不足、制约生产的瓶颈问题。     

Q195冷轧板材轧制困难原因分析

针对部分Q195冷轧板材存在轧制困难的现象，进行了现场检验与分析。带状组织、混晶现象严重导致变形强化系数偏高是造成轧制困难的主要原因。