半固态ZnAl 27合金及其二次加热组织

研究了半固态ZnAl27合金及其二次加热组织。结果表明，半固态ZnAl27合金基本无宏观偏析，其组织为细小均匀的近球形非枝晶，综合力学性能远远高于常规铸造合金；二次加热后，α相进一步球化，边缘变得光滑圆整，可以满足半固态触变成形的需要。     

实炉底节能连续式加热炉

轧钢生产使用实炉底连续式加热炉加热钢坯，炉内双纵滑管用耐热耐高温材料，无水冷，起到节约水、电的作用，达到节能增效的目的。     

氧量分析仪在加热炉上的应用

介绍了仕富梅700B型氧量分析仪在加热炉的成功应用，阐述了设备型号的选择。检测设备的安装位置，环境选择及设备维护均是设备能充分发挥效能的重要环节。     

REHEATING TEMPERATURE CONTRAST AND MICROSTRUCTURES OF 7075 Al ALLOY CAST BY LIQUIDUS SEMI-CONTINUOUS CASTING

In this study, reheating of liquidus semi-continuous cast billets of 7075 Al alloy was carried out in a resistance furnace, and the temperature contrast of the outer and the center of the reheated billets was investigated, then the reheating microstructures were investigated. Results show that: the difference of temperature between the outer and center is small and the difference of their microstructures are also small. During reheating at 576℃ the spheroidization of grains is significant after 5min and no rosettes are visible after 20min by optical microscopy. Similar observations were madeon materials reheated at 596℃, but the ripening process is faster. The grains growup to 30-60μm, fine enough for thixoforming.     

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.     

钢水化学热法升温技术的研究

依据热力学原理，用计算机计算了某些元素与合金的氧化热效应。综述了各种上化学热法升温技术的应用效果。分析讨论了发热剂的类型，升温速度和热效率问题等。     

基于炉区分段的BP神经网络钢坯温度预测

利用神经网络可以逼近任意非线性系统的特点,建立加热炉内钢坯温度预报模型。由于钢坯的边界热流系数和热传导系数、比热、重度等物理参数都是随温度变化的函数,所以,按加热炉的分区采用多个BP神经网络进行分段预测,以适应钢坯的物理参数的变化。仿真结果表明:所建模型简单,精度高,能满足工程实际需要。     

A2017半固态合金二次加热工艺及组织演化机制

相同加热温度条件下,随着保温时间的延长,晶粒逐渐长大和球化,液相分数增加;提高二次加热温度,晶粒长大和球化速度加快.在620～625℃加热,保温40～60min,可获得由均匀球形晶粒悬浮于液相组成的半固态组织,晶粒大小为70～90μm,液相率为40%～45%.而常规铸造枝晶A2017合金坯料二次加热后仍然保留粗大的枝晶网络结构.半固态合金锭坯二次加热初期晶粒的熔合合并是晶粒长大的主要方式,相界面能的升高和相界面表面张力是组织演化的主要驱动力.     

热轧生产过程加热炉优化调度模型及算法

钢铁生产中的加热炉调度问题是一类复杂的组合优化问题。本文进一步考虑不同轧制位对应的候选板坯集存在交集的生产实际,建立了以板坯住炉时间最小为优化目标的数学模型,提出了三阶段的启发式算法,确定各轧制位板坯的入炉和出炉时间。仿真实验表明,给出的模型和求解算法对加热炉调度问题的优化效果很好。     

基于PLC的步进式加热炉演示系统设计

本系统以八一钢铁股份有限公司棒材厂加热炉控制现场为背景,设计完成了步进式加热炉演示系统.系统采用西门子S/-200系列PLC为核心,通过检测传感器信号,根据加热炉控制工艺,并利用MCGS组态软件实现了对步进式加热炉工作情况的上位监控,为过程控制和PLC等相关课程提供实验平台.