超低碳钢方坯连铸钢水关键精炼工艺研究

介绍了小方坯连铸超低碳钢水的转炉冶炼、LF精炼和RH真空处理的生产工艺,针对钢水可浇性差和钢中Si含量偏高问题进行工艺技术优化。试验研究表明,降低LF脱硫任务,采用少渣精炼,造渣料石灰加入量控制在6. 5~7. 5 kg/t有利于钢包顶渣改质和控制钢中[Si]含量;RH根据经验公式确定吹氧量,既能满足强制脱碳的需要又可防止钢水过氧化,破真空后用高铝渣对顶渣进行改质,控制渣中TFe质量分数小于1. 0%,并对钢水Ca处理,有效提高了钢水的可浇性,顺利实现超低碳钢小方坯连铸。     

控制Ca添加量以提高低碳铝镇静钢的洁净度

为确定防止浸入式水口堵塞并提高钢洁净度所需的最小Ca添加量，本研究进行了两个浇次共14炉的试验。第一浇次的试验目的在于获得实际可能达到的最小Ca添加量，第二次旨在稳定该添加量水平。采用金相显微镜观察和扫描电镜分析（SEM／EDx）对试验结果进行评估。研究结果表明，将Ca添加量从0．095kg Ca／t钢降低到0．06kg Ca／t钢，可以成功预防浸入式水口堵塞。研究结果还证明，该添加量具有把氧化铝夹杂转变为球状钙铝酸盐的效果，并将CaS夹杂含量从4％～41％减少到0．05％～7．61％的范围。     

SWRCH22A冷锻钢100 t LF精炼造渣制度的分析和工艺优化

为减少钢中夹杂物和对夹杂物变性处理,防止连铸水口结瘤,对100 t LF 5炉SWRCH22A冷镦钢（/%:0.18~0.20C,0.44~0.62Si,0.85~0.89Mn,0.012~0.015P,0.006~0.009S,0~0.004Ca,0.000 7~0.0010B,0.011~0.088Als）夹杂物钙处理进行了Ca-Al,Al-O,Al-S,Ca-S平衡热力学计算和氧氮分析。得出1 873 K[Ca]-[Al],a[O]-[Al]和[S]-[Al]平衡曲线,1 823~1 923 K[Ca]-[S]平衡曲线,和5炉钢对应的实测值。通过分析,得出优化LF精炼工艺:（1）精炼终渣MgO=6%、SiO₂<6%、CaO/Al₂O₃=1.6~1.8;（2）转炉下渣量700 kg左右,精炼终渣量2 000 kg左右;（3）根据精炼终渣CaO/Al2O3=1.6~1.8的目标来决定造渣料的加入量;（4）避免喂钙线时钢水剧烈翻腾,并防止精炼结束到中间包过程钢水的氧化     

SWRCH22A冷镦钢100 t LF精炼造渣制度的分析和工艺优化

为减少钢中夹杂物和对夹杂物变性处理,防止连铸水口结瘤,对100 t LF 5炉SWRCH22A冷镦钢(/%:0.18~0.20C,0.44~0.62Si,0.85~0.89Mn,0.012~0.015P,0.006~0.009S,0~0.004Ca,0.000 7~0.001 0B,0.011~0.088Als)夹杂物钙处理进行了Ca-Al,Al-O,Al-S,Ca-S平衡热力学计算和氧氮分析。得出1 873 K[Ca]-[Al],a_([0])-[Al]和[S]-[Al]平衡曲线,1 823~1 923 K[Ca]-[S]平衡曲线,和5炉钢对应的实测值。通过分析,得出优化LF精炼工艺:(1)精炼终渣MgO=6%、SiO_26%、CaO/Al_2O_3=1.6~1.8;(2)转炉下渣量700 kg左右,精炼终渣量2 000 kg左右;(3)根据精炼终渣CaO/Al_2O_3=1.6~1.8的目标来决定造渣料的加入量;(4)避免喂钙线时钢水剧烈翻腾,并防止精炼结束到中间包过程钢水的氧化。     

提高低合金钢钢水质量的研究

结合攀钢实际情况,在生产低合金钢时,出钢过程向钢包内加入高碱度精炼渣,出钢后加入调渣剂,并在LF炉补加少量高碱度精炼渣和0.30～0.60 kg/t铝丸;以及将精炼后钢包底部软吹氩时间延长至6 min以上,改善了钢中夹杂的去除条件,大幅度提高了钢水质量,钢中T[O]平均为14.69×10-6,[S]平均为0.007%,[N]＜50×10-6,非金属夹杂中B、C类夹杂较少,A、D类夹杂多为0.5级.     

50t氧气顶吹转炉高锰生铁合金化试验研究

介绍了某钢厂的生产现状及工艺流程,阐述了高锰生铁合金化原理。通过在50 t氧气顶吹转炉进行高锰生铁合金化试验研究,分析高锰生铁合金化对钢水温度、钢水成分及炼钢钢铁料消耗的影响。试验结果表明,在出钢过程向钢包加入高锰生铁进行合金化是可行的,且有可观的经济效益。平均每炉加入200 kg高锰生铁进行合金化时,钢水温降增加4. 68℃,钢水磷质量分数增加0. 000 6%,但是对转炉钢水质量无影响,同时炼钢增碳剂消耗减少0. 22 kg/t,硅锰合金节省0. 45 kg/t,钢铁料消耗降低0. 44 kg/t。最终每年为钢厂创效270. 4万元。     

对钢中形成氧化物-硫化物复合夹杂物的热力学评价

采用钙处理不仅可以提高钢水的可浇性以及洁净度，而且还可对夹杂物进行变性处理以改善钢水质量。钙能使固态氧化铝夹杂物变性，对钢水进行脱氧，同时形成液态铝酸钙。钢水化学成分决定其可能形成硫化钙（CaS）和／或者各种不同形式的铝酸钙。硫化物通常与氧化物相共生，也就是我们熟知的典型氧化物-硫化物复合夹杂物。在钢包处理过程中，必须避免在钢水中形成固态硫化钙，因为它不利于钢水的可浇性。本文开发了在铝镇静钢中，预测由在[O]，[S]和[Ca]之间通过竞争反应形成氧化物-硫化物复合夹杂物的热力学模型。将本文开发的模型与文献中报道的那些模型进行了比较，同时对从钢厂收集到的钢样进行夹杂物类型观察。结果表明，为了在钢中得到完全的液态铝酸钙，而不形成硫化物，要求钢中的硫含量极低。随着钢中硫含量的增加，使氧化铝夹杂全部转为液态铝酸钙的难度也在增加。避免形成CaS的最大硫含量取决于钢水化学组成，主要是铝含量。硫化物夹杂通常为CaS和MnS的固溶体，同时也完成了该体系的热力学分析。根据对现有工作的分析，可能预测到硫化物组成对形成复合夹杂物的影响。     

钙处理钢中夹杂物行为的研究

为改善武钢CSP产线钢水的连浇性,通过工业试验对钙处理钢中夹杂物的变化进行了研究,试验结果表明,钙处理后,钢中夹杂由Al2O3和MnS转变为铝酸钙盐或CaO-Al2O3-MgO-CaS复合夹杂,由于钙处理对夹杂物的聚合变性作用,钢中夹杂物直径不小于5μm的比例增加。通过热力学计算,分析了钙处理使夹杂物变性的条件。根据试验结果对工艺进行了优化,钢水结瘤断浇次数由3.6次/月降低到1.5次/月。     

20G钢非金属夹杂物的行为研究

针对某钢厂在生产20G钢初期,存在表面裂纹,低倍检验不合格的问题,对其生产过程中非金属夹杂物类型、数量、来源、尺寸及分布进行了综合分析。研究表明:正常铸坯中显微夹杂物平均总体积率0.149%,连浇坯中显微夹杂物平均总体积率为0.184%;正常坯中大型夹杂物平均含量为1.81 mg/kg,连浇坯中含量为3.31 mg/kg,其夹杂物主要来源于结晶器液面保护渣,其次中包覆盖剂和钢包渣卷入也是钢水污染的一个原因。     

低碳钢夹杂物产生原因及控制

 CSP线100 t转炉生产SPHD冷轧夹杂物降等比例比较高,经分析夹杂降等主要原因是钢水夹杂物去除不彻底。通过优化转炉脱氧工艺减少夹杂产生,提高转炉终点温度减少LF处理过程中钢水中铝的氧化;精炼炉采用钢包渣循环渣利用快速造白渣,控制钢包渣w((CaO))/ w((Al₂O₃))为1.4～1.8,碱度为18～25,喂钙线前白渣时间大于8 min, LF炉出站镇静大于15 min促进夹杂的去除;开浇前中间包用氩气吹扫2 min、加硅钙粉防止开浇塞棒上涨,确保浇铸过程中恒拉速、钢包换包时中间包钢水大于20 t减少液位波动。最终基板夹杂降等率由1.8%降低至0.2%。     

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。     

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。     

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.     

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)     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.