中厚板双边剪模拟剪切的研究

针对双边剪生产过程中的钢板跑偏问题,提出了双边剪模拟剪切模式。该模式增加了控制软件功能,能够在不剪切钢板的情况下验证夹送辊调整是否满足要求,节省试切钢板。在实际生产中有效地预防和解决了剪切跑偏问题,提高了成材率和作业率。     

弹丸高速冲击条件下高强度钢板抗弹性能

为了研究弹丸高速冲击条件下不同洁净度的40CrNi2Mo钢板的抗弹性能,利用12.7 mm穿甲燃烧弹对抗拉强度分别为800和1 200 MPa级的钢板进行抗弹性能测试。通过观察不同强度钢板出现的损伤形貌,评定背面强度极限,分析了穿甲机制。结果表明:抗拉强度为800 MPa级的钢板在弹丸冲击过程中以塑性扩孔方式侵彻,抗弹性能随着强度升高而提高,与洁净度关系不大。抗拉强度为1 200 MPa级的钢板,弹丸冲击过程中因钢板较低的绝热剪切临界失稳应变而出现绝热剪切;由于塑韧性较低,低洁净度钢板阻止绝热剪切引发裂纹扩展的能力较弱,因此形成与绝热剪切相关的裂纹,导致抗弹性能降低;高洁净度钢板抗弹性能相对较高,因背面出现剪切裂纹而失效,此裂纹与绝热剪切无关。     

弹丸高速冲击条件下高强度钢板抗弹性能

摘要：为了研究弹丸高速冲击条件下不同洁净度的40CrNi2Mo钢板的抗弹性能，利用12.7mm穿甲燃烧弹对抗拉强度分别为800和1200MPa级的钢板进行抗弹性能测试。通过观察不同强度钢板出现的损伤形貌，评定背面强度极限，分析了穿甲机制。结果表明：抗拉强度为800MPa级的钢板在弹丸冲击过程中以塑性扩孔方式侵彻，抗弹性能随着强度升高而提高，与洁净度关系不大。抗拉强度为1200MPa级的钢板，弹丸冲击过程中因钢板较低的绝热剪切临界失稳应变而出现绝热剪切；由于塑韧性较低，低洁净度钢板阻止绝热剪切引发裂纹扩展的能力较弱，因此形成与绝热剪切相关的裂纹，导致抗弹性能降低；高洁净度钢板抗弹性能相对较高，因背面出现剪切裂纹而失效，此裂纹与绝热剪切无关。     

双边剪夹送辊的同步控制系统

双边剪夹送辊同步控制系统经过参数调整及系统优化,实现了控制系统与现场电机的完美匹配,使钢板的运行方向得到保证,防止了钢板在剪切过程中跑偏,改善了钢板的剪切质量,钢板宽度误差为0～10mm、错刀差为0～0.5mm。     

圆盘剪切边钢板跑偏的影响因素分析及对策

结合炉卷轧线的生产实际,通过分析圆盘剪剪切过程中造成钢板跑偏的各种原因,找到了存在的问题并进行了全面的改进,从而提高了剪切质量和钢板成材率。     

钢板跑偏原因分析及改进措施

宝山钢铁股份有限公司厚板厂双边剪采用西门子控制系统进行剪切控制。本文针对双边剪在送板过程中出现的钢板跑偏现象进行研究和分析,并通过降低送板加速度、优化夹送辊同步控制、提高电流限幅等措施,有效改善了钢板跑偏现象,提高了钢板剪切质量。     

钢板剪切边开裂原因分析及改进剪切质量的措施

针对钢板原始剪切边在用户再加工过程中产生边部开裂的问题,采用钢板纵向样进行了实验室模拟试验,分析认为,边部开裂的主要原因是钢板原始剪切面剪切弯钩、毛刺引起的应力集中及再加工工艺不当。剪切间隙、重叠量调整、剪切温度、剪切力、剪切量等因素都影响钢板的剪切质量。结合安钢实际情况,采取新上风雾冷却装置,降低钢板剪切温度,优化剪刃重叠量、水平间隙调整工艺及热态毛边放尺量等措施,提高了钢板剪切质量,减少了质量异议。     

钢板自动定尺模型在滚切式横剪系统中应用

通过在滚切式定尺剪的定尺设备上建立剪切钢板长度为控制变量的钢板自动定位数学模型,使剪切设备根据钢板剩余的剪切长度进行自动速度调节,实现了滚切式横剪系统的全自动运行、精确定位及精确剪切功能,提高了钢板的剪切质量,增加了系统的稳定性。     

通过带卷连续剪切过程控制钢板的力学性能

在连续限制剪切的过程中 ,通过均一角状孔型的连续带卷剪切工艺 ,引入了金属在连续运作的模式中可重复使钢板成形的新概念 ,并对观察到的金属剪切变形曲线进行了数学模拟和试验室研究。利用观察到的带卷连续剪切组织作出剪切流曲线 ,验证了该试验方法的正确性。利用有限元法预测带卷剪切过程中产生的剪切变形及有效变形。同时在 TEM下观察其显微组织 ,并研究了斜角即剪切应力对硬度变化的影响通过带卷连续剪切过程控制钢板的力学性能@焦晓渝     

纵芬带钢边部裂纹问题的探讨

从钢板剪切抗力的分析入手，着重研究了钢板在剪切过程中所受弯曲力和扭转力的作用机理，对边部裂纹问题进行了一系列探讨，找出了影响断面质量的原因，并提出改进措施。     

粉煤灰提取氧化铝工艺能耗分析

介绍了粉煤灰预脱硅-碱石灰烧结法、盐酸浸取法和硫酸焙烧法提取氧化铝的工艺方法,计算和分析了以上三种工艺的理论能耗。结果表明,三种工艺中预脱硅—碱石灰烧结法能耗最高,为1 707kgce(每吨Al_2O_3,下同),其中烧结工序就占总能耗的53.67%;盐酸浸取法与硫酸焙烧法能耗较低,分别为1 396kgce和1 476kgce,比预脱硅—碱石灰烧结法分别降低了18.3%和13.5%。盐酸浸取法中42.57%的能耗集中在AlCl_3·6H_2O晶体热解工序,而Al_2(SO_4)_3·18H_2O晶体脱水能耗占硫酸焙烧法总能耗的51.38%。     

黄铜矿的湿法冶金工艺研究进展

介绍了黄铜矿湿法冶金的最新进展及工艺特性，探讨了黄铜矿湿法冶金的发展前景。Dynatec加煤粉流程和CESL二段浸出流程很好地解决了中温压力氧化酸浸过程中单质硫的影响，对材质的耐腐蚀性要求低，在低能耗下获得了高的浸出效果，对于主要分布于黄铜矿中的含金铜精矿，可获得很高的金回收率。Intec和Hydro Copper工艺在常压低温氯化介质中很好地浸出黄铜矿精矿，并能同时回收伴生的贵金属．生产的中间产品铜粉可直接加工高附加值产品，能耗低，回收率高，是复杂铜精矿湿法冶金的途径．Geocoat工艺的诞生使得高品位黄铜矿精矿大规模高温细菌氧化浸出成为现实，它克服了细菌浸出对设备要求高的缺点，利用堆浸的优势，以低的运行成本获取高的黄铜矿浸出率。     

安钢RH精炼工艺中的质谱炉气分析系统

对于高品质钢的冶炼,RH真空循环脱气工艺功能强大,技术效益显著,目前在国内的应用越来越普遍。采用质谱炉气分析系统在线分析RH工艺过程气体成分,结合流量、温度测控技术,可以实现对RH工艺的过程优化和终点控制。本文介绍了在安钢第二炼轧厂RH工艺中采用的质谱炉气分析系统,包括其组成、安装布局、分析性能和在现场的工作模式等。采用吹氧脱碳处理工艺、不吹氧脱碳处理工艺和脱气处理工艺对炉气分析系统进行测试表明：该系统能够实时、连续和准确地反映处理过程中各成分随时间的变化;60米采样距离,系统总滞后时间小于40s;炉气成分变化过程同处理工艺完全吻合。可预见采用炉气分析技术,可为RH精炼工艺的终点控制及工艺的实时调整提供判据,从而缩短RH冶炼时间,提升冶炼品质。     

低碳钢在RH工序碳粒脱氧的生产实践

对低碳钢RH工序碳粒脱氧工艺进行了论述。通过理论分析与实际工艺方案的设计,对RH工序碳粒脱氧工艺过程的到站温度、真空度、环流气体流量、吹氧等环节进行了有效控制。与原单纯使用铝脱氧的工艺比较,有效降低了合金成本,减少了夹杂物含量,提高了钢水纯净度。     

中钇富铕稀土矿萃取分离新工艺研究

报道了萃取分离中钇富铕稀土矿新工艺，第一步La～Gd/(Gd)TbDy(HoY)/Ho～LuY萃取分离，出口水相La～Gd组份再Nd/Sm分组；中间出口的(Gd)TbDy(HoY)组份Tb/Dy分离。进行了扩大试验和工业生产应用。与中钇富铕稀土Nd/Sm先分组的传统工艺相比，处理能力提高约35%，P507存槽量减少约40%，贵重Tb、Dy稀土从第一步就出口，流程短、收率高。     

湿法炼锌除铁工艺研究

介绍了常规法、热酸浸出、氧压浸出、针铁矿和赤铁矿等几种湿法炼锌除铁工艺,重点对SO2还原浸出、热酸还原浸出、氧压还原浸出的赤铁矿除铁工艺的各项指标进行了比较。含铁低的原料,适宜采用常规工艺和针铁矿工艺;含铁高的原料适宜采用黄钾铁矾法和赤铁矿法;而氧压浸出工艺两种原料都能适应。     

Spheroidization process in large-deformed high-carbon steel

In this study,the spheroidization process of large-deformed steel under various conditions was researched. Steel with a high carbon content(1.0% C)was first treated thermomechanically using multipass rolling.Then it underwent spheroidization treatments at different heating temperatures,using various heating times and cooling rates.Spheroidization processes with a lower heating temperature,shorter heating time,or faster cooling rate than those of the traditional process all showed good results,indicating that the spheroidization process was promoted significantly by the large deformation process.Grain refinement and fragmentation of cementite,along with the large deformation process,promoted this spheroidization process.     

Study on Austenite Grain Growth Law of Ultra-High Strength Hot-Stamped 22MnB5 Steel During Thin Slab Casting and Rolling Process

Clarifying the austenite grain growth law in the thin slab casting and rolling (TSCR) process can provide theoretical guidance for the control of austenite grain in the slab. Starting with the austenite nucleation during solidification process, the growth law of austenite grains is methodically studied throughout the TSCR continuous casting and soaking process. The results show that the austenite growth is not interrupted during the TSCR continuous casting and soaking process. The austenite grain growth in the continuous casting process accounts for more than 70% of the total growth. The growth rate of austenite in the continuous casting cooling process is always faster than that when reheated to this temperature. Compared with the holding temperature and holding time, the final size of austenite grains in the TSCR process slab is most affected by the continuous casting cooling rate. In addition, compared with the traditional process, the growth rate of austenite in TSCR process is faster at the end of soaking.     

Microstructural Evolution and Properties of a High Strength Steel with Different Direct Quenching Processes

A high strength low alloy steel with low carbon equivalent was selected for simulating online direct quenching and coiling(DQ-C)process.The influence of stop quenching temperature on mechanical properties and microstructures was studied and compared with normal direct quenching and tempering(DQ-T)process.The study confirmed that required mechanical properties were obtained for both the processes.Properties of the experimental steel with DQ-C process could reach the same level as that of DQ-T process in general.In the DQ-C process,strength decreased with increase in stop quenching temperature.Martensite was obtained and experienced an aging process at stop quenching temperature below Mf.On fast cooling below Ms,martensite was partially transformed and carbon partitioning occurred during slow cooling.The reduction in solid solution carbon and increased amount of retained austenite led to lower strength compared with the DQ-T process.DQ-C process was more favorable for microalloy carbide precipitation.However,impact toughness under different cooling conditions was adequate because of low carbon equivalent and refined microstructure.     

An unusual cause of low back pain. Osteomyelitis of the spinous process

STUDY DESIGN: A case report of osteomyelitis of the spinous process. OBJECTIVE: To describe the diagnosis and successful treatment of a patient with spinous process osteomyelitis. SUMMARY OF BACKGROUND DATA: Spinous process osteomyelitis is exceedingly rare and may be misdiagnosed as paraspinal muscle strain, discitis, or vertebral body osteomyelitis. The clinical presentation of spinous process osteomyelitis is subtle, laboratory findings are nonspecific, and radiographs are often normal. METHODS: The diagnosis, treatment, and outcome of two patients with spinous process osteomyelitis (an adult and a child) with insidious, nonspecific lumbar pain and fever are reviewed. RESULTS: Magnetic resonance imaging with and without gadolinium enhancement demonstrated increased signal of the spinous process with paraspinous musculature enhancement, a finding consistent with spinous process osteomyelitis. Biopsy results demonstrated the presence of staphylococcus aureus in the child and no organisms in the adult. Treatment with intravenous antibiotics led to resolution in both cases. CONCLUSIONS: The use of magnetic resonance imaging technology permitted the early and accurate diagnosis of spinous process osteomyelitis.