对先进熔融还原工艺关键点的评价

经过15年的研究开发,有几种熔融还原工艺已到了中间设备试验阶段.对AISI(美国钢铁协会)、DIOS(铁矿直接熔融)和HIsmelt工艺的一些数据进行了对比.本文简要讨论了反应机理,评价了几个关键操作参数.AISI和HIsmelt工艺的主要区别在于装料方式的不同.HIsmelt对铁矿和煤使用深喷方法,而AISI和DIOS凭借重力给料;HIsmelt使用空气加氧气,而AISI和DIOS只使用氧气.这些区别会对还原、炉子粉尘产生和二次燃烧产生影响.这三种工艺的还原速率相当,但是对于HIsmelt,当喷吹的矿粉通过铁碳熔体时也产生一些还原.在HIsmelt中,当使用高挥发分煤时,由于其挥发分的有效燃烧,产生的粉尘量和粉尘中的碳含量都很低.这也是其达到较高二次燃烧率的原因之一.在这三种工艺中,硫和磷在渣铁之间都达到了平衡.而HIsmelt工艺因为其在较低温度下操作且温度分布更均匀,所以其达到了较高的硫磷分配比(即铁水中含量较低).     

70t电炉生产弹扁工艺优化实践

介绍了八钢70t电炉生产60Si2Mn钢的工艺技术优化及冶炼的效果,分析了电炉生产弹簧钢的技术要点及影响因素。通过采取相应的技术措施确保了电炉产品的质量。     

PIDAS工艺评估和工艺设计模型开发

随着PIDAS系统在宝钢厚板的建立与应用,生产、工艺、设备、性能数据得到了系统的采集、整理,海量工业数据的价值得到了有效的挖掘,开始发挥重要作用.基于PIDAS,首先开发了一种工艺评估模型,与传统的性能预测模型相比,它能根据工艺参数,预测产品性能值所在的区间,以及真实值位于此区间内的概率.此模型使用了自主开发的概率区间估计算法,通过全面评估不同机器学习回归模型的效果、充分考虑历史生产数据的分布规律,来预测产品性能值所在的区间,取得了良好的效果.在此基础上,又开发了一种工艺设计模型,它能够根据化学成分、产品规格和性能目标,设计出最优的轧制工艺参数.此模型应用了自主开发的自定义权重的模拟退火算法.所提出的工艺评估和工艺设计模型均取得了良好的效果,达到产品质量预报和优化工艺设计的目的.     

氮化锰制备工艺研究进展

锰、氮作为冶金添加物质,在钢铁冶炼中起着重要的作用.将锰、氮元素以氮化锰化合物的形式加入时体现出许多优点,因此氮化锰的制备工艺得到了长足的发展.文章重点讨论了几种典型的氮化锰制备工艺的研究现状与进展.     

综采工艺在铝土矿开采中的应用浅谈

伴随着国民经济的发展,人们对于铝土矿资源的需求缺口越来越大,传统开采方式难以满足现代人们的需求,主要在于传统铝土矿开采的生产能力较低,损失率较高,采出率较低,安全系数低。随着时代进步,需要注重对铝土矿资源的合理开采,提高铝土矿的资源生产效率以及回收率。分析煤矿综采工艺在铝土矿资源开采中的运用,促进铝土矿安全、高效、可持续发展。     

钢中稀土加入工艺技术研究与应用

为解决钢中稀土加入难题，济钢开发了结晶器喂稀土金属丝工艺，即采用SLW2-4(A)多齿辊无级调速结晶器稀土喂丝机，通过严格控制原始钢水的脱氧程度，合理选择喂丝工艺参数，提高了钢中稀土成分的合格率．稀土回收率达80％以上，稀土在钢中的分布基本均匀。在09CuPTiRE和JCL355等部分钢种应用表明，稀土在钢中有净化、变质和微合金化的作用，钢中夹杂物总量评级平均只有5级，比正常生产钢降低2．2个级别以上。     

球状金属颗粒在流动熔体中熔化过程的数学模型

针对冶金过程中常涉及到的固态金属在液态金属中的熔化过程建立数学模型,用焓法描述相变过程,采用有限体积法,对过热熔体中球状金属颗粒熔化过程及其影响参数进行研究.结果表明,金属颗粒的熔化受颗粒初始温度、熔体过热度以及熔体流动强度的影响.熔体流动对相变影响作用较大,受周围流体对流强度的影响,颗粒从表面凝固壳形成到熔化过程呈现非均匀性,在靠近上游的颗粒前端以及下游尾迹处颗粒熔化速度较快,而颗粒边缘熔化速度较慢.     

The development of urologic complications in relationship to bladder pressure in spinal cord injured patients

Usually the upper ankle joint is described as a typical hinge though it had been often remarked that the axis of rotation moves considerably with regard to the angular adjustment between the tibia and the trochlea tali. In the present study the relation between the movements in the upper ankle joint and the geometry of the lateral ligaments was analysed. The contours and elected landmarks of 6 dissected ankle joints were measured using a digitizer which allowed the computerized scanning of motion x-rays. In addition the proximal and distal insertion planes of the lateral ligaments were registered. Mathematical procedures were applied on the experimental data to predict the kinematic principles. The model of an hinged joint could not reproduce the motion curve which was actually found. Using the model of a link chain with four pivots, which was determined by the course of the talofibular and the calcaneofibular ligament, a good correlation with the experimental results was evident. This model implies a rotary and gliding component in the movement of the tibia against the trochlea tali. Beside the correspondence with the data of the present study the model allows an easy explanation of many other well known morphologic phenomena of the upper ankle joint for which a stringent interpretation was not yet available.     

UK20运矿车液压系统设计及计算

UK20运矿车载重量为20 t,前后机架采用铰接式结构,转向采用双缸、倾翻卸料采用双缸,转向、倾翻卸料采用先导手柄控制液控换向阀进行控制,制动采用弹簧制动液压释放湿式多盘制动器,安全可靠。     

New hinged silicone penile implant

A new paired hinged silicone prosthesis is described. The hinge allows the penis to move freely and hang in a dependent position without constrictive clothing and permits satisfactory coitus. A conical tip more nearly conforms to the distal corpus and the proximal end may be trimmed during the operation to fit the individual patient.     

Two-stage treatment process of pickling wastewater in the cold-rolling production of stainless steel

Based on the characteristics of pickling wastewater in the cold-rolling production of stainless steel,a new processing route,featuring source sludge reduction,wastewater two-stage treatment,heavy metal-contained sludge and calcium salt sludge separating recovery,was proposed.As shown by the research results,after the two-stage process treatment,the effluent water can steadily reach the emission standards,the sludge yield can be decreased by more than 8%;within the heavy metal-contained sludge,the recovery rates of Fe,Cr and Ni can either reach or surpass 95%,and the total content of F and S can drop to around 3%.Therefore,the sludge in the front part can be used as ferric dust.In the calcium salt sludge,the recovery rate of F can either reach or surpass 85%,and the total contents of Fe,Cr and Ni can fall below 0.5%.So the sludge in the rear part can be used as fluorgypsum or fluorite.Meanwhile,the results of the analysis on heavy metals leaching toxicity and morphologic distribution indicate that the two kinds of sectionalized sludge are not classified as hazardous wastes,which have a stable behavior and better utilization values compared with the former mixed-sludge.     

Summary of SAC Case Study Building Analyses

Summarized in this paper are the major findings from analytical studies of nine steel moment frame buildings conducted under Phase 1 of the SAC Steel Project. The buildings range in height from two to seventeen stories and most of them experienced damage to welded beam-column connections during the Northridge earthquake of 1994. Elastic response spectrum, inelastic static pushover, and elastic and inelastic time-history analyses were conducted using ground motion data representative of the Northridge earthquake to establish the loading∕deformation demands that the buildings experienced. The primary performance indices obtained from the analyses were demand-to-capacity ratios, interstory drift ratios, and inelastic hinge rotations. Maximum ratios of elastic member force demands to plastic strengths ranged between 1.0 and 2.0; maximum inelastic hinge rotations were 0.005–0.010 rad; and maximum interstory drift ratios were from 1 to 2%. These damage indices increased by 50%–150% under more severe ground motions recorded during the Northridge earthquake at the Sylmar site. Accuracy of the analyses is shown to be sensitive to a number of modeling parameters including finite joint size, joint panel behavior, composite beam action, strain hardening, second-order (P-Δ) effects, and three-dimensional response. Overall, there was only modest correlation between the frame performance indices and the observed connection damage, due largely to the fact that significant aspects of the connection fracture behavior are not captured in the frame analyses.     

小松铰卡分动箱拆装新工艺

城门山铜矿目前拥有10台小松HM400-2铰卡,自2017年设备进入大修期后,分动箱开始出现漏油及内部磨损故障,需要对分动箱进行拆卸检修。而按小松铰卡装配手册拆卸步骤,需要将变速箱和分动箱一起拆卸吊出后,才能对分动箱进行拆装及检修,需耗费大量人工。针对分动箱拆装困难的难题,我们对其安装方式及结构进行分析,研究发明一种分动箱拆装新工艺,节省了大量人工成本及检修时间,此方法亦对其他设备总成件拆装具有借鉴意义。     

CSP热轧过程中夹杂物周围孔洞的演变

借助于动态显式有限元软件ABAQUS/Explicit,模拟了CSP热轧过程中,板坯厚度方向上不同位置处直径为50μm的Al2O3夹杂物周围孔洞的形成和演变过程。结果表明,对于不同位置处的Al2O3夹杂物,在它们沿轧制方向的前、后部位都形成了孔洞,但前孔洞面积大于后孔洞面积;夹杂物越靠近板坯表面,形成的孔洞越大;热轧过程中,孔洞的演变是一个"愈合—长大—愈合"的动态过程;随着道次的增加,夹杂物前、后孔洞在轧制方向上的投影长度变化与面积变化趋势相一致,而与孔洞尖端夹角的变化趋势恰好相反;孔洞在热轧过程中发生转动,导致前孔洞尖端朝着带钢表面扩展。模拟结果有助于揭示夹杂物周围孔洞与表面缺陷的关系,并为实际生产提供理论指导。     

铌钛复合微合金化载重汽车轮辐钢板的研制

通过合理设计成分和性能，采用Nb Ti复合微合金化技术和结晶器喂稀土丝等工艺，开发生产了JCL355载重汽车轮辐钢板,JCL355钢的平均屈强比达0．77，钢板晶粒度在8级以上。经用户使用验证，JCL355钢冲压和焊接性能良好，耐疲劳性能达到原用20g钢板的2倍。