控制冷却中钢板的翘曲解析

控制冷却中钢板的翘曲解析［日］吉原直武等１绪言现在，各公司都装有中厚板在线控制冷却设备，生产高强度、高韧性并且焊接性优良的产品。在尺寸大的中厚板在线控制冷却中，不容易获得上下面的冷却平衡，难以避免发生上下方向的翘曲。另外，由于冷却设备通板方面的原因，...     

采用快速冷却工艺提高大口径天然气管线钢厚板的力学和工艺性能

最近,用户对大口径钢管用低合金钢板的要求越来越高,一方面是由于管道使用条件苛刻,要求钢管在具有良好塑性和焊接性的同时,还应具备良好的强度和抗断裂性;另一方面是出于降低成本的要求。为生产出满足上述要求的钢板,在厚板轧机上开发出了热机械控轧工艺（ТМСР）,工艺包括热机械控轧（КП）和轧后快速冷却（УО）。实施该工艺要求轧机装备有现代化自动控制装置,保证轧件以规定速度冷却到指定温度,同时还要保证冷却均匀,钢板不翘曲。     

堆垛缓冷过程模拟及对钢板性能的影响

应用analysis软件对船板钢连铸坯堆垛缓冷温度场进行数值模拟计算,并对不同堆垛缓冷制度下的轧制钢板取样进行金相组织、Z向拉伸断口形貌、拉伸性能等分析,研究了不同堆垛缓冷工艺对钢板性能的影响。结果表明:堆垛铸坯冷却速率最快的是顶部铸坯,而中间区域和底部区域的冷却速率较慢,断面为300 mm×2 400 mm的船板钢连铸坯堆冷铸坯的平均冷却速率为8.1~14.2 K·h-1。随着堆垛缓冷时间的延长,钢板的拉伸断口分层、带状组织、中心偏析等缺陷得到有效控制,断面为300 mm×2 400 mm的船板钢连铸坯堆垛缓冷36 h可以有效避免拉伸断口分层等缺陷的发生。     

09MnNiDR钢板正火工艺的研究

通过研究09MnNiDR钢板的CCT曲线,确定了该钢种合理的正火冷却速率范围;同时比较了常规空气冷却存在的冷却速率不足的缺点,采用新型加速冷却工艺,细化晶粒,最终改善了钢板的实物质量。     

厚钢板控制冷却中的翘曲解析

籍助于具有一维应力和热弹塑性材料的梁型开发了一种关于控制冷却期间钢板翘曲的数字解析方法。为证实这种解析的有效性,应用新设计的实验装置进行了实验。测量了温度和翘曲的连续变化。（1）该解析的有效性经与实验结果比较被定量地证实。期待着该计算方法被用于控制冷却过程中钢板和型钢的翘曲控制。（2）根据解析结果,发现翘曲的主要原因是相变、屈服应力和导热系数。①在低温转变场合,冷却期间的翘曲行为和残余翘曲都较大,因为有相变时大的膨胀和低温下高的屈服应力。②较高的屈服应力导致较大的翘曲。③较低的导热系数导致在厚度方向上高的、陡峭的温度梯度,它将引起较高的热应力和较大的翘曲。     

控制冷却过程中钢板翘曲的分析

采用一维应力和热弹性材料的梁式模型，对控制冷却过程中钢板的翘曲进行了分析。为了验证这种分析的可靠性，用新设计的实验装置做了试验。在水冷过程中，测定了温度与翘曲的连续变化。（１）通过与试验结果的比较，定量地验证了这种分析的可靠性，预计这种计算方法将被用于控制冷却过程中钢板翘曲的控制。（２）由此分析结果可以得出：引起翘曲的主要因素是相变、屈服应力和导热性。ａ）在低温相变条件下，冷却期间的翘曲和残余翘曲     

水温对冷轧马氏体钢板淬火冷却速度和性能的影响

冷轧马氏体钢板以其高强度特点,在汽车零部件制造中具有较大的减重潜力,逐步获得越来越多的应用.冷轧马氏体钢板一般采用具有水淬冷却功能的连续退火机组生产,水淬过程工艺参数对马氏体钢板的组织和性能影响很大.以C-Mn系冷轧马氏体钢板为研究对象,研究水温对淬火冷却速度、钢板的力学性能和组织的影响.结果表明,在室温较低的情况下,马氏体薄钢板的冷速可达近1 000 K/s.随着水温的变化,不仅平均冷却速度发生改变,而且瞬时冷却速度曲线的形状也发生较大的变化.水温提高导致冷却速度下降,从而导致马氏体钢板强度和组织的较大变化.这种变化规律,对于马氏体钢板性能稳定控制有一定的参考意义.     

HTP型X65管线钢的开发与生产

介绍了济钢在3200／3500mm双四辊轧机上首次大规模研制生产X65管线钢的工艺和性能。所研制的管线钢采用低C、S、P和高Nb、无V、Mo的成分设计，有低的碳当量CE（≤0．34）和PCN（≤0．17）。应用精轧机HTP和ACC快速冷却工艺获得针状铁素体组织，采用堆垛缓冷实现热扩散处理，获得优良性能。采用所开发的X65管线钢板制成的直缝埋弧焊钢管具有良好的力学性能和焊接性能。     

热处理钢板气雾冷却数学模型的开发与应用

针对某钢厂新建的热处理钢板气雾冷却装置,基于有限差分传热仿真计算,开发了相应的热处理钢板气雾冷却数学模型,其中详细考虑了钢板在冷却区内所经历的多种传热边界条件,包括水冲击传热、辊子接触传热、辐射传热和自然对流传热。通过现场的钢板表面温度测试工作表明,模型预测值与实际测试值之间的吻合情况较为良好,模型具有较高的仿真精度。应用该模型,按照一定的热处理工艺要求（主要指对出口温度和钢板表面／中心温降速率的控制）,对气雾冷却区进行了冷却水表的理论设计（即各种厚度规格钢板所对应的冷却水流量）,其设计结果已成功地应用于生产现场。     

高品质980 mm x 1 960 mm电渣扁锭轧制 164 mm x 1 700/1 806 mm 12Cr2MolVR 钢板研发

12Cr2Mo1VR钢板生产的流程为100 t EAF-LF-VOD-CC-ESR-轧制工艺。电渣重熔过程中,采用熔速降低(160～180) kg/h及氮气保护等工艺;轧制过程采用低速大压下量轧制工艺;轧后采用650～700℃长时保温扩氢退火工艺;热处理采用930～950℃正火(加速冷却)+680～700℃回火工艺。生产的钢板表面质量良好,探伤级别满足NB/T47013.3-2015及第1号修改单TⅠ级要求,钢板成分、显微组织均匀,力学性能满足技术要求。     

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。     

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.     

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.