邯钢成功试制汽车用烘烤硬化钢镀锌板HC220BD＋Z

近日,邯钢公司成功试制汽车用超低碳烘烤硬化钢镀锌板HC220BD十Z．、规格为0．8X1250mm,表面质量均为一级。经检验,力学性能、烘烤硬化值等均满足用户使用要求,烘烤硬化钢的特点是冲压成形前较软、易成形加工,通过涂漆中的烘烤过程使屈服强度增加,主要用于汽车外覆盖件。随着汽车工业的发展,烘烤硬化钢用量正逐年增加,特别是在国内、外的中高端轿车的应用较为广泛。镀锌板烘烤硬化钢既可以提高汽车外板的耐腐蚀性、延长汽车寿命,又能通过提高外板的抗凹陷性,达到实现汽车轻量化的目的。     

各向同性钢与烘烤硬化钢的烘烤硬化性和抗凹陷性

 研究了烘烤温度、烘烤时间和预拉伸应变量对罩式炉退火工艺生产的各向同性钢的烘烤硬化性的影响，并与力学性能相当的冷轧烘烤硬化钢进行了对比。结果表明，在不同的烘烤条件下，各向同性钢的烘烤硬化值均低于同样强度级别的烘烤硬化钢。抗凹陷性测试结果表明，各向同性钢的抗凹陷性低于烘烤硬化钢。汽车外板实物分析结果表明，两种钢冲压成形后再烘烤，其屈服强度几乎没有提高。     

不同成分体系对超低碳烘烤硬化钢性能的影响

研究了不同成分体系超低碳烘烤硬化钢的性能特征,生产结果表明:Ti-BH钢屈服强度和BH值较低,伸长率和"值富裕量较大,并且BH值波动较大.通过对不同成分体系钢板的微合金化原理进行分析,确定了不同成分体系烘烤硬化钢性能不同的原因,并据此将烘烤硬化钢的成分体系由Ti-ULC改为Nb+Ti复合体系.更改后的烘烤硬化钢性能指标...     

应用铁素体区轧制工艺生产ELC钢

通过铁素体区热轧工艺生产ELC钢的工业试验,研究了一种ELC钢的热轧组织、织构及性能。结果表明,铁素体区热轧后,ELC钢大部分为变形带组织,放大1 000倍可以看到鱼骨状的晶内剪切带;热轧后,织构沿板厚方向均匀分布,织构的遗传性使得冷轧和退火后的织构沿板厚方向也均匀分布,但是退火织构中仍有{001}<110>织构存在;退火后钢板的r值在1.3左右,达到普通冲压级钢板的要求。     

车体外面板用高功能高强钢板

JFE开发了两种生产汽车车体外板面板用的高功能高强钢板。一种是SFG钢板,主要用于生产要求深冲性的侧面板部件,SFG钢通过精粒细化增大了强度,并且低屈服强度（低YS）,高n值（高兰克福特值）决定的高成形性使其成为精粒细化型高强钢板。另一种是“万能高强钢”,这种钢主要用于车门、车蓬等处,其优点在于拉伸性能好、表面形状质量高（耐表面变形性）,冲压成形后的烤漆可以加强钢的硬度,在尽可能保证耐电镀性基础上减少了厚度,又可称为低YS（低屈服强度）型440MPa级BH（烘烤硬化）钢。     

武钢开发轿车用热轧钢板

经过 3年多的技术攻关 ,武钢轿车用热轧钢板系列开发工作已取得突破性进展。通过对化学成分的设计 ,转炉冶炼、连铸、控轧及控冷工艺及其数学模型等的研究 ,已基本掌握了该系列钢材性能的关键工艺要点。现已开发出热轧车轮轮辐用钢、车架梁用钢、热轧冲压轿壳用钢、轿车结构件用钢、热轧深冲用钢板及拉延钢板等。形成了 32 0～ 540 MPa的轿车及轻型车用热轧钢板系列生产能力。其中车架梁用钢、热轧深冲酸洗板、车轮钢等产品 ,经汽车制造厂冲压汽车零件、装车试制 ,均达到用户工艺技术要求 ,部分产品质量达到了进口同类钢板实物水平 ,实现了…     

影响电镀锌镍烘烤硬化钢屈服强度的因素分析

介绍了电镀锌镍烘烤硬化钢的特性和其冲压过程中材料本身性能的变化,并研究了生产工艺对其重要力学性能指标--屈服强度的影响,对于理论研究和生产实践具有一定的指导意义.     

不同成分体系镀锌烘烤硬化钢特点

介绍不同成分体系的极低碳烘烤硬化钢汽车板实际生产情况,生产结果表明：NbULC、Ti-Nb．ULC成分体系的BH钢BH值波动较小。采用高温退火的Nb．ULC成分体系的BH钢较低温退火的Ti—Nb—ULC成分体系的BH钢R90、△r值大而n值稍低。同时通过对Ti-ULC、Nb-ULC、Ti—Nb—ULC三种成分体系钢板的生产实绩和7台金原理进行分析,确定了不同成分体系烘烤硬化钢性能不同的原因,并据此提出了可能的相关生产控制要素。     

预变形和烘烤对超高强度冷轧钢板二次变形特性的影响

以两种强度均在980MPa以上的超高强钢为研究对象,研究预变形和烘烤对不同马氏体含量钢的力学行为和断裂方式的影响。结果表明,随着预应变量的增加,两种试验用钢的烘烤硬化值均先增加,当达到最高点后又发生转折、下降;弯曲—烘烤—二次弯曲试验表明,在较大的预变形条件下,二次弯曲性能下降;超高强钢经较大的预变形和烘烤后,屈强比大大提高,延伸率明显下降;断口分析发现,在预应变量不同的情况下,烘烤后的拉伸断口明显不同,较大的预应变量对应的断口韧窝较浅,局部解理微区较多,尺寸也相对较大。     

碳含量对TRIP型双相钢深冲性的影响

1前言 近年来,环境保护要求轿车车体实现轻量化和提高轿车的冲撞安全性,在为此目的而开发出的高强度钢板中,利用残余奥氏体(γR)相变诱发塑性(TRIP)原理开发出的TRIP双相钢(TDP)具有非常良好的冲压成型性.590MPa级热轧TRIP钢板已经实际应用到轿车前梁等吸收冲击能的部件和车轮总成部件.TDP钢今后的发展是扩大应用到高强度钢板难成型部件,并用拼焊材料代替现有材料,在轿车车体轻量化和冲撞安全性方面发挥更大的作用.     

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)     

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。     

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.