提高烧结低温余热发电机组发电作业率和发电量的措施

分析、研究了导致烧结低温余热发电机组发电作业率和单位小时发电量低的主要原因,在此基础上提出了提高烧结低温余热发电机发电组作业率和单位小时发电量措施.     

搞好攀钢烧结备料上料工作的几点措施

通过对备料车间皮带上料系统物料运输能力的理论核定和对设备运转作业率、上料作业率等主要上料运转参数的实际调查。得出了上料作业率低、分料、消石灰上料占用设备时间长是造成供料困难的主要原因，并提出解决问题的几点措施。     

提高方坯连铸机作业率的实践

通过分析影响方坯连铸机作业率的各因素,制定塞棒与水口的装配原则,优化各钢种保护渣理化指标及结晶器电磁搅拌的电流参数,稳定钢液过热度等措施,减少了影响连铸机实际作业率的寨棒失控及溢漏钢等断流事故,从而提高了连铸机的实际作业率.     

提高1550mm酸轧机组作业率的攻关实践

对1550mm酸轧机组日历作业率进行分析,查找存在不足,从人员管理、生产组织管理、设备改造和设备点检等角度制定攻关措施,使日历作业率由年初的71.75%提高到86.75%,机组年产量突破150万吨。     

提高烧结矿产量的生产实践

鞍钢股份有限公司炼铁总厂近几年为增加烧结矿产量,自2013年以来,利用现有生产线,采取了提高烧结机利用系数、作业率和增大烧结机有效烧结面积等措施,取得了显著效果。至2015年底,烧结机作业率提高11.53%,烧结矿增产近200万t。     

艾萨炉生产指标优化探讨

介绍了艾萨炉炉寿、作业率以及能耗的情况,分析探讨了以上指标的优化措施.     

艾萨炉生产指标优化探讨

介绍了艾萨炉炉寿、作业率以及能耗的情况,分析探讨了以上指标的优化措施。     

415m^2鼓风环式冷却机的改进

分析了415m^2鼓风环式冷却机的常见故障,提出和实施了相应的改进措施,使设备作业率稳步提高。     

提高热轧带肋钢筋切分作业率的生产实践

宣钢公司二棒生产线为提高产线作业率,优选采用高速钢轧辊后,切分单槽轧制量在950 t以上。通过减少换辊换槽次数、加强生产过程控制,降低千吨堆钢率、实施小改小革,消除"工艺事故点"等措施,确保了生产线设备运行稳定,提高作业率。     

提高球团回转窑作业率的攻关

分析柳钢氧化球团生产线回转窑设备作业率偏低的原因,介绍实施的开发新型回转窑窑衬结构、回转窑窑头改型、下环冷机受料装置耐火材料改型、液压站动力管网优化、粒度分离器改型、支撑托轮大轴承受力点切换、热工制度与生产操作的优化等措施,使设备作业率提高了4%,年提高产量16万吨。     

The effect of grain size, strain rate, and temperature on the mechanical behavior of commercial purity aluminum

Commercial purity aluminum AA1050 was subjected to equal channel angular extrusion (ECAE) that resulted in an ultrafine-grained (UFG) microstructure with an as-received grain size of 0.35 μm. This UFG material was then annealed to obtain microstructures with grain sizes ranging from 0.47 to 20 μm. Specimens were compressed at quasi-static, intermediate, and dynamic strain rates at temperatures of 77 and 298 K. The mechanical properties were found to vary significantly with grain size, strain rate, and temperature. Yield stress was found to increase with decreasing grain size, decreasing temperature, and increasing strain rate. The work hardening rate was seen to increase with increasing grain size, decreasing temperature, and increasing strain rate. The influence of strain rate and temperature is most significant in the smallest grain size specimens. The rate of work hardening is also influenced by strain rate, temperature, and grain size with negative rates of work hardening observed at 298 K and quasi-static strain rates in the smallest grain sizes and increasing rates of work hardening with increasing loading rate and grain size. Work hardening behavior is correlated with the substructural evolution of these specimens.     

仲钨酸铵晶体生长速率常数和活化能研究

采用“成核期积分平均速率法”,运用阿累尼乌斯实验定律,求出仲钨酸铵晶体生长的表观活化能E表=94.657kJ/mol,得出仲钨酸铵晶体生长速率常数与温度的关系式为kn=8.46×1014exp(-94657/RT)。研究结果表明,温度升高,APT成核速率的增长幅度大于晶体生长速率的增长幅度,结晶产品粒度变细。     

硫氢比与钢板探伤合格率关系调研

通过对重庆钢铁股份有限公司生产的低合金钢Q345R硫氢比与钢板探伤合格率关系的综合分析,得出随着硫氢比的提高、钢板探伤合格率呈上升趋势的基本结论。     

Influence of strain rate on the stress-strain curve in the range of Lüders strain

The influence of strain rate on the stress-strain curve of materials showing yield point phenomenon are determined in the range of small strains and high strain rates by means of the indirect impact tension test. With increasing deformation velocity, the Lüders strain is found to increase considerably. The stress reduction after reaching the upper yield point, is not abrupt and takes place gradually with increasing strain. These phenomena are investigated on Armco iron, on the tempered steel 42 CrV 6, on pure tantalum and tungsten alloys. A simple mechanical model is introduced which shows that the Lüders front velocity increases with strain rate approaching asymptotically the value of the plastic wave velocity as an upper limit. With this restriction, the local strain within the Lüders band must increase by increasing the rate of elongation of the tensile specimen. The Lüders strain could be estimated quantitatively as a function of strain rate. The model describes also the stress-strain function after reaching the upper yield point considering the limited stiffness of the test arrangement.     

SHPB加载作用下考虑节理分形的闭合变形性质研究

为了探讨动载荷作用下的节理闭合变形性质,用水泥砂浆制作出含节理的人工试样,并采用SHPB装置对具有不同分形（JRC）的含节理试样进行不同加载率作用下的冲击试验,获得了不同加载率下具有不同Barton标准 JRC值的节理动态闭合变形曲线。冲击后试样及其结果分析显示：随着加载率的增加,碎裂的块数明显增加,表现出较强的加载率相关性;节理闭合变形曲线的变化趋势基本不受加载率的影响,节理变形量δ均随着应力σ的增大而增大。在加载速率相同的情况下,不同节理形貌试样的节理法向变形量存在较大差异;具有相同节理的试样在不同加载率作用下的闭合变形曲线也是显著不同的;无论加载率多大,δ和σ之间均具有很强的指数关系,可用统一的公式表达。该研究成果为进一步开展动载荷作用下节理闭合变形本构方程研究提供了试验基础。     

炼钢过程中钢液氢含量的变化及分析

为了进一步降低钢中氢含量,保证探伤合格率,利用G8 GALILEO-ON/H分析仪对铸坯进行定氢,结果表明,随着铸坯氢含最的增大,钢板探伤合格率逐渐降低,其氢含量(质量分数,余同)小于(2～3)×10-6时探伤合格率为100%;用贺利式定氢仪测定炼钢过程中氢含量的变化并对其进行了分析,结果表明,转炉复吹和LF精炼是主要...     

等静压成型工艺参数对高纯石墨制品的影响研究

实验研究了高纯石墨材料制备过程中,等静压成型工艺参数对制品的影响.研究了升、降压速度,等静压压力及保压时间、包套长径比对压坯体积密度的影响.结果表明,降低升压速度、增加等静压压力有利于提高制品密度,适当的降压速度、保压时间和包套长径比可使压坯致密均匀.     

Influence of Strain Rate,Temperature, Plastic Strain,and Microstructure on the Strain Rate Sensitivity of Automotive Sheet Steels

This work identifies the influence of strain rate, temperature, plastic strain, and microstructure on the strain rate sensitivity of automotive sheet steel grades in crash conditions. The strain rate sensitivity m has been determined by means of dynamic tensile tests in the strain rate range 10^?3–200 s^?1 and in the temperature range 233–373 K. The dynamic flow curves have been tested by means of servohydraulic tensile testing. The strain rate sensitivity decreases with increasing plastic strain due to a gradual exhausting of work hardening potential combined with adiabatic softening effects. The strain rate sensitivity is improved with decreasing temperature and increasing strain rate, according to the thermally activated deformation mechanism. The m‐value is reduced with increasing strength level, this decrease being most pronounced for steels with a yield strength below 400 MPa. Solid solution alloying with manganese, silicon, and especially phosphorous elements lowers the strain rate sensitivity significantly. Second phase hardening with bainite and martensite as the second constituent in a ferritic matrix reduces the strain rate sensitivity of automotive sheet steels. A statistical modeling is proposed to correlate the m‐value with the corresponding quasistatic tensile flow stress.     

基于离散元理论的自然崩落法放矿细颗粒渗移过程研究

为探讨自然崩落法放矿过程中废石细颗粒的渗移规律及诱因,利用离散元软件EDEM分别从粗细颗粒数量比、直径比及矿岩含水率三个方面对细颗粒的渗移过程进行模拟,并设置标志颗粒对不同区域的相邻粗细颗粒进行跟踪.研究结果表明:放矿提前贫化率随粗细颗粒数量比的增大不断降低;废石细颗粒渗移速率随粗细颗粒直径比的增大而增大,且受含水率影响显著;相邻位置的细颗粒的渗移速度大于粗颗粒的下降速度.研究结果为进一步探讨矿石损失贫化、确定采场结构参数及优化放矿管理制度提供理论支持.