变形量对EH40钢连续冷却转变的影响

利用Thermecmastor 100 kN热模拟压缩机进行实验,应用热膨胀法绘制EH40级船板用钢在33.3%、50%变形量下的连续冷却转变曲线,应用OM、SEM和TEM图像并配合硬度法研究了EH40级船板用钢不同变形量的连续冷却转变产物及组织特点。实验结果表明,冷却速度在1～5℃/s时,实验钢组织以多边形铁素体为主;冷却速度在5℃/s以上时,组织为少量铁素体、粒状贝氏体的混合组织;变形量越大,显微组织尺寸越小,贝氏体组织含量越多;在相同变形条件下,冷却速度越大,实验钢硬度值越高。     

铌-钛微合金化高强钢连续冷却的相变规律

利用Gleeble 3500热模拟试验机研究了铌-钛微合金化试验钢在变形与未变形条件下的连续冷却相变规律。研究结果表明:试验钢在2~50℃/s的较大冷速范围内均可获得贝氏体组织,且随着冷却速度的增加,组织中粒状贝氏体的量下降,板条贝氏体的量增加;同时变形促进相变,有利于奥氏体中新相的形成。用热膨胀法建立了试验钢静态与动态条件下的连续冷却转变(CCT)曲线。     

27SiMn钢CCT曲线的测定

在Gleeble1500D热模拟机上利用膨胀法测定了27SiMn钢在不同冷却速度下连续冷却转变的膨胀曲线,获得了该钢的连续冷却转变曲线(CCT曲线),利用蔡司显微镜观察了不同冷速下试样的金相组织,借助莱卡硬度计测定了各试样的显微硬度值.随着冷却速度增加,硬度值越来越大.通过对CCT曲线的分析为生产工艺的制定提供了一定的实验依据.     

低合金高强钢形变奥氏体相变行为及其模型

 为了研究低合金高强钢的形变奥氏体连续冷却转变行为及组织变化规律,利用Gleeble-3800热力模拟试验机对试验钢进行了多道次轧制工艺模拟试验,并根据试验所得相变温度和各冷却速度下的室温组织相对量,回归出相变模型。结果表明,试验钢在变形后的连续冷却过程中发生铁素体、珠光体、贝氏体和马氏体转变,基于对各转变的温度和组织相对量得到的相变模型分析,证实了模型的可靠性。     

工艺参数对耐蚀钢12CuCrNiV组织与性能的影响

采用热力模拟试验机、光学显微镜、显微硬度计研究了耐蚀钢12CuCrNiV在不同冷却速率下的连续冷却组织转变规律,并绘制其CCT曲线,同时研究了形变温度和冷却速度对耐蚀钢热变形后的组织和硬度的影响规律。结果表明:连续冷却转变情况下,耐腐蚀钢在冷速小于15℃/s时,有铁素体转变;冷速小于1℃/s时,有珠光体转变;冷速在0.5~20℃/s之间时,有贝氏体转变。控制冷速在5~15℃/s可得到铁素体和贝氏体复相组织。随变形温度的降低,试验钢形变过程中形变诱导铁素体相变现象显著,且伴随有M/A岛生成;随冷却速度的增高,形变诱导相变现象减弱,M/A岛数量减少。与连续冷却试验相比较,形变诱导析出现象明显,其硬度增量为40~50HV,形变可使试验钢的析出向更高冷速移动。     

Q690钢的过冷奥氏体连续冷却转变曲线

采用Formastor-F型全自动相变仪测定Q690钢的连续冷却转变曲线(CCT曲线),研究了Q690钢在不同冷却速度下的显微组织形态,分析了合金元素对连续冷却转变曲线的影响,通过对CCT曲线的测定为Q690钢热处理制度和控冷工艺提供理论依据.     

含钛低合金超高强耐磨钢的连续冷却相变行为

在MMS-300热力模拟实验机上对一种含钛低合金超高强耐磨钢进行热模拟实验,研究了热变形奥氏体在连续冷却转变过程中的相变行为,建立了其连续冷却转变曲线(CCT曲线),观察了不同冷速下的组织变化情况,并探讨了精轧阶段变形量和变形温度对试验钢组织和性能的影响.结果表明,变形促进了先共析铁素体和珠光体的转变,缩短其孕育期,在...     

TMCP工艺对微合金高强度钢组织性能的影响

  在实验室条件下,对一种微合金高强度钢进行热膨胀试验和热轧试验,测定了该试验钢的连续冷却转变动力学(CCT)曲线,并研究了不同温度转变的组织和第二相的体积分数、尺寸对其力学性能的影响。试验结果表明：变形温度的降低,贝氏体转变开始温度与转变结束温度均升高,硬度值也出现不同程度的提高;变形温度的降低,使得不同冷却速度下组织细化程度存在明显差异。利用合理控轧控冷工艺,使得屈服强度均达到690MPa以上,-30℃冲击功均达到230J以上。其中,第二相粒子在整个基体内呈细小弥散分布,起到有效的强化作用并改善钢的冲击韧性。     

X70级别耐磨管线钢连续冷却转变规律研究

采用■型热膨胀仪,对X70级别管线钢在不同冷却速度下的连续冷却转变规律进行研究,结合金相法建立了试验钢的连续冷却转变曲线,并通过光学显微镜对在不同冷却速度下得到的显微组织进行观察。结果表明:随着冷却速度的增加,奥氏体-铁素体相变温度逐渐降低,并向贝氏体组织转变,获得耐磨管线钢合适组织的冷速为10～30℃/s。     

不同硼含量微合金钢的连续冷却相变行为

 利用热模拟试验技术对实验室制备的含硼微合金钢连续冷却转变形为进行了试验研究,利用光学显微镜研究冷却速度、变形对试验钢显微组织的影响,探讨了硼对转变行为的影响规律。结果表明：适量硼延缓多边形铁素体生成,有利于获得贝氏体组织;无硼及wB=00020%时,分别在1~25及05~25℃/s的冷速都能得到贝氏体组织;wB=00030%时,冷速在2℃/s 以上能得到贝氏体组织;与未变形相比,变形导致试验钢贝氏体冷速区间变窄。在同一冷速下,随硼含量增加贝氏体开始转变温度先降低再升高,显微硬度随硼含量增加先增加而后降低。     

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。     

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。     

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.     

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)