Q195L钢方坯连铸二冷技术的优化

针对韶钢Q195L钢方坯存在严重的中心裂纹和中心缩孔问题,对方坯连铸二次冷却工艺进行了试验优化.通过建立凝固数学模型计算二冷区的铸坯表面温度分布,分析并调整连铸比水量和二冷区水量分配,制定了满足Q195L钢连铸工艺要求的二冷控制制度.生产应用表明,Q195L钢连铸坯内部质量明显提高,铸坯中间裂纹不大于1级的比例由90.74%提高到100%,中心缩孔不大于1级的比例由83.33%提高到92.50%,中心疏松不大于1级的比例由96.30%提高到97.50%.     

360mm×450mm大方坯连铸二冷技术研究

针对攀钢360 mm×450 mm连铸大方坯存在的表面纵裂、中间裂纹、中心裂纹等质量问题,通过采用适当增大连铸比水量、调整二冷区各回路的冷却能力及水量分配比例的方法,优化了大方坯连铸二冷制度.生产应用表明,大方坯表面质量和内部质量明显提高,因铸坯中间裂纹严重而产生的表面纵裂缺陷率由53.85%降至0.30%,铸坯中心疏松评级≤1.0级的比例由74.87%增至99.53%,无中心裂纹的比例由68.83%增至82.77%,无中间裂纹的比例由82.95%增至90.98%.     

含钒高氮高强耐候乙字钢大方坯连铸二冷技术

针对攀钢高强耐候乙字钢大方坯连铸二冷控制制度在连铸比水量和二冷区水量分配等方面存在的问题,通过采用延长喷水冷却区长度、适当增大连铸比水量、调整二冷区各回路的冷却能力及水量分配比例的方法,优化了YQ450NQR1大方坯连铸二冷制度.生产应用表明,高强耐候乙字钢大方坯内部质量明显提高,中心疏松评级≤1.0级的比例由79.71%增至90.70%,中心偏析＜0.5级的比例由1.45%增至44.19%,无中心缩孔的比例由86.96%增至93.02%,无中心裂纹的比例由39.13%增至62.79%,无中间裂纹的比例由85.51%增至88.37%,无皮下裂纹的比例由78.26%增至97.67%,无角部内裂纹的比例由73.91%增至93.02%,为攀钢开发生产屈服强度450MPa级高强度耐大气腐蚀乙字钢提供了高质量的铸坯.     

凌钢2号方坯连铸机二冷制度的优化

凌钢通过对2号方坯连铸机二冷制度的优化结果表明,采用合理的喷嘴型号和布置以及适当的水量控制等制度,对减轻铸坯中心偏析、扩大铸坯等轴晶率、提高铸坯内部质量有明显效果,铸坯合格率由优化前的87.26%提高到优化后的99.81%,为进一步完善连铸二冷控制制度奠定了坚实的基础.     

改善轴承钢GCr15矩形坯缩孔的生产实践

通过对本钢矩形坯生产GCr15铸坯缩孔的成因分析,同时对GCr15的浇铸工艺进行了大量的生产试验研究工作,提出了采用合适的二冷制度、轻压下制度和拉速,以及严格控制过热度等改善矩形坯缩孔缺陷的措施。实践表明:采用改进工艺后铸坯质量得到了明显改善,不大于1.0级的铸坯缩孔比例提高到95%以上。     

改善二冷系统提高连铸小方坯的质量

分析了新疆八一钢铁有限公司第一炼钢厂1#连铸机二冷存在问题对120 mm×120mm断面连铸坯质量的影响,通过缩短外弧、侧弧喷淋管支管长度,使连铸坯在二次冷却时趋于均匀;降低HPB235钢二冷冷却强度,优化了二冷配水制度,取得了较好的效果：脱方废品率由0.034%逐渐降低到0.003%;中间裂纹率由10%降到8%,平均裂纹级别由原来2.0级降至1.5级;轧钢质量异议由5起降低到1起。     

260mm×300mm合金钢连铸坯质量控制集成技术的开发和应用

简述了莱钢50 t EAF-LF(VD)-CC流程中合金钢260 mm×300 mm连铸坯质量控制集成技术的开发和应用效果.通过合理的铸坯纯净度和全程保护浇铸,二冷动态控制的二冷工艺设备设计,工艺设备精度参数群优化,热装工艺的铸坯质量在线预报判定系统等控制技术的开发,提高了铸坯质量,钢材酸浸低倍检验合格率由2007年的97.50%提高到2009年的99.01%,铸坯合格率在99.92%以上,成材率由原来的96.50%提高到%.80%,铸坯热装率由45%提高到75%.     

360mm×450mm大方坯连铸二冷技术研究

针对攀钢360mm×450mm连铸大方坯存在的表面纵裂、中间裂纹、中心裂纹等质量问题,通过采用适当增大连铸比水量、调整二冷区各回路的冷却能力及水量分配比例的方法,优化了大方坯连铸二冷制度。生产应用表明,大方坯表面质量和内部质量明显提高,因铸坯中间裂纹严重而产生的表面纵裂缺陷率由53．85％降至0．30％,铸坯中心疏松评级≤1．0级的比例由74．87％增至99．53％,无中心裂纹的比例由68．83％增至82．77％,无中间裂纹的比例由82．95％增至90.98％。     

25MnSiV矩形连铸坯疏松缩孔模拟研究

建立了25MnSiV矩形连铸坯凝固组织数学模型，研究了拉速、过热度、二冷区给水量对连铸坯疏松缩孔的影响规律。结果表明，提高拉速和过热度均会增加铸坯疏松缩孔比例，而增加二冷区给水量能降低铸坯疏松缩孔比例，最佳工艺参数分别为拉速1.0 m/min、过热度20℃、二冷区给水量为最大给水量的60%。     

S650MC高强钢连铸轻压下工艺优化

为解决S650MC钢热轧卷拉伸试样出现一定比例的分层问题,针对影响拉伸分层主要原因之一的铸坯中心偏析质量进行了动态轻压下工艺优化试验。结果表明:在固相率为20%~75%压下区间,压下量由3.6 mm提高至4.4 mm;总压下量由4.5 mm提高至5.5 mm的工艺方案能显著提高其中心偏析质量;S650MC钢铸坯中心偏析评级由原来的平均B1.0级提高至C1.0级,热轧卷拉伸试样出现分层比例由4.20%下降至0.78%。同时也表明二冷电磁辊对S650MC钢中心偏析质量改善效果不明显,但能提高铸坯中心等轴晶比例2%~3%。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.