SKF钢包炉精炼钢中Al_S含量对夹杂总量的影响

精炼车轮钢的化学成分(%)为:Ｃ0.60±0.02,Ｓｉ0.25±0.03,Ｍｎ0.75±0.03,Ｓ、Ｐ<0.020。钢中夹杂物采用ＡＳＴＭ标准评级,要求Ｂ类(Ａｌ2Ｏ3)夹杂<1级,Ａ类(硫化物)夹杂<2级、Ｃ类(硅酸盐)夹杂<2级、Ｄ(点状氧化物)夹杂<2级。为了保证车轮钢的质量,对工业生产中的数据进行了分析研究,确定出用铝的工艺参数。1　精炼工艺　　精炼炉采用90ｔＬＦＶＤ(ＳＫＦ)钢包炉,设有除渣、加热、真空处理3个工位,具有加热、电磁搅拌、成分微调、真空处理、吹Ａｒ搅拌等功能。工艺流程:初炼钢水→除氧化渣→脱氧造渣→ＬＦ(升温、脱氧、微调)→ＶＤ→搅拌…     

P110石油管坯水平连铸工艺改进和质量控制

20 0 2年衡阳钢管公司成功研制生产了2 6ＣｒＭｏＮｂＴｉＢ钢水平连铸管坯 ,用于生产 3 0 0 0ｍ以下油井中使用的Ｐ1 1 0级石油管。1　 2 6ＣｒＭｏＮｂＴｉＢ钢的技术要求及工艺钢中有害元素要求为 :ΣＡｓ +Ｓｎ +Ｐｂ +Ｓｂ +Ｂｉ≤ 0 0 4 0 %、Ｐ≤ 0 0 1 5 %、Ｓ≤ 0 0 1 0 %。要求铸坯无近表面裂纹 ,一般和中心疏松≤2 .0级 ,点状偏析≤ 2 .5级 ,缩孔残余≤ 2 .0级 ,中间和中心裂纹≤ 1 .0级。铸坯每米弯曲度不得大于 1 0ｍｍ ,总弯曲度不得大于总长度的 1 .0 %。工艺流程为 :电弧炉冶炼→ＬＦ二次精炼→ＶＤ真空处理→喂丝→加合…     

铁道车辆用LZ50钢精炼工艺的控制

随着火车的不断提速 ,对铁道车辆用车轴钢的质量要求越来越高。铁道部于 1 999年 2月颁布新标准《铁道车辆用ＬＺ50车轴及钢坯技术条件》(ＴＢ Ｔ2 945 1 999)。为满足车轴钢新标准要求 ,实现铁路运输快速、安全、重载的目标 ,北满特钢公司发挥现有先进设备的优势 ,合理地制定工艺路线及工艺参数 ,对ＬＺ50钢的化学成分、非金属夹杂物、力学性能、气体含量、晶粒度等理化指标进行控制 ,使车轴钢的冶炼达到一个新水平。1　新铁标对ＬＺ50钢的要求铁道部颁布的新铁标 (ＴＢ Ｔ2 945 1 999)等效采用美国铁路协会ＡＡＲＭ 1 0 1 90热处理及非热…     

45钢高速机车轴坯的试生产

为满足机车车轴用钢需要 ,中国铁路物资总公司与本钢特殊钢公司签订了机车轴坯试制合同 ,按ＪＣＺＰ 0 1 98《铁路机车用车轴坯订货技术条件》及ＭＳＣ 98 2 0《机车轴坯试制合同》试制了 2 80ｍｍ× 2 80ｍｍ× 650 0ｍｍ的轴坯。试制的轴坯和经锻制的机车轴 ,经铁道部及车辆产品质量监督检验部门检验 ,各项指标满足轴坯和车轴技术条件要求。1　试制工艺和检验项目试制工艺为 :30ｔＥＢＴＥＡＦ→ 40ｔＬＦ→ＶＤ→喂丝→模铸 5ｔ锭→红送→ 80 0 /650成坯→入坑保温→检查→超声波探伤→包装入库。本钢特钢公司、铁道部产品质检中心 ,戚…     

本钢铁道车辆用LZ50钢车轴坯的研制

本钢采用铁水预处理、12 0t顶底复吹转炉冶炼、LF +RH TB二次精炼、4 8t钢锭 80 0轧机成坯工艺试生产了铁道车辆用LZ5 0钢 (% :0 4 7～ 0 5 5C ,0 17～ 0 4 0Si,0 6 0～ 0 90Mn) 2 30mm× 2 30mm车轴坯。LZ5 0钢材中氢含量为 (0 5～ 0 7)× 10 -6,氧 (9～ 10 )× 10 -6,氮 (5 5～ 70 )× 10 -6。A +C类非金属夹杂级别为1 0～ 2 5。LZ5 0钢 84 0℃正火处理后的机械性能为σs370～ 385MPa ,σb710～ 735MPa ,δ52 1%～ 2 3%。     

重轨钢连铸结晶器电磁搅拌技术应用研究

针对大方坯连铸机投产初期重轨钢连铸电磁搅拌冶金效果不明显的问题,开展了优化重轨钢连铸结晶器电磁搅拌工艺参数的现场试验,对比研究了电磁搅拌电流强度对重轨钢铸坯中心疏松、中心偏析、等轴晶率等内部质量的影响,制定了满足攀钢重轨钢连铸工艺要求的电磁搅拌工艺制度.生产应用表明,重轨钢连铸坯内部质量明显提高,铸坯中心区等轴晶率由18.8%增至36.2%,中心疏松≤1.5级,中心偏析≤1.0级,中心缩孔≤1.0级,中心碳偏析指数≤1.05,连铸坯轧成重轨的内部质量和力学性能能够满足350 km/h高速铁路用钢轨的要求.     

CAS冶炼低碳低硅铝镇静钢的生产实践

新钢第二炼钢厂采用KR→BOF→CAS→CC工艺路线生产低碳低硅铝镇静钢,通过控制入炉铁水硫含量、转炉出钢挡渣及脱氧合金化、CAS精炼造渣及钙处理、连铸保护浇铸及稳定结晶器液面等措施,钢水可浇性增强,可实现一个浇次生产10炉及以上,钢水满足客户要求,w (Si)控制在0. 03%以下,低倍结果显示铸坯质量良好,C类中心偏析为1. 0级,中心疏松0. 5级。     

70t DC EBT EAF-LF生产FT9780非调质钢的工艺实践

非调质抽油杆钢ＦＴ9780要求含 0 .0 1 2 %～0 0 1 8%Ｎ ,钢材使用强度大于 60ＭＰａ。为防止白点等缺陷 ,又要求 [Ｈ]尽可能低 ,所以生产该钢有一定难度。本文介绍生产该钢的工艺实践。1　主要设备工艺该钢种由 70ｔＤＣ ＥＡＦ与 70ｔ单臂钢包炉生产 ,连铸由 4机 4流 ,断面为 1 2 0ｍｍ× 1 2 0ｍｍ～1 40ｍｍ× 1 40ｍｍ方坯连铸机浇注 ,其中电弧炉由兑铁水配碳 ,ＢＳＥ自耗式炉门Ｃ Ｏ枪进行泡沫渣操作和成分控制 ,ＥＢＴ出钢 ,冶炼周期 (4 7± 5 )ｍｉｎ ,最大出钢量 80ｔ,ＬＦ最大升温能力 4.5℃ ｍｉｎ ,处理时间要求在 45ｍｉｎ以…     

湘钢提高特厚钢板内部质量生产实践

通过优化LF渣系,VD和LF的吹氩制度以及连铸的工艺参数,有效地提高了钢水的洁净度和板坯质量,优化后钢水中w(P)≤0.015%、w(S)≤0.003%、w(O)≤4×10-6、w(H)≤1.3×10-6、w(N)≤40×10-6。板坯的中心偏析和疏松均为C类1.0级,钢板中心偏析和疏松均为C类0.5级;钢板平均探伤合格率提高了3.15%,探伤合格率最高达到了99.51%。     

结晶器电磁搅拌改善重轨钢连铸坯内部质量的试验研究

针对攀钢大方坯连铸机投产初期重轨钢连铸电磁搅拌冶金效果不明显的问题,开展了优化重轨钢连铸结晶器电磁搅拌工艺参数的现场试验,对比研究了电磁搅拌电流对重轨钢铸坯中心疏松、中心偏析、等轴晶率等内部质量的影响,制定了满足攀钢重轨钢连铸工艺要求的电磁搅拌工艺制度.生产应用表明,重轨钢连铸坯内部质量明显提高,铸坯中心区等轴晶率由18.8%增至36.2%,中心疏松≤1.5级,中心偏析≤1.0级,中心缩孔≤1.0级,连铸坯轧成重轨的内部质量和力学性能能够满足时速350 km高速铁路用钢轨的要求.     

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。     

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。     

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.     

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.     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.