控轧控冷工艺对低合金高强钢Q460力学性能的影响

通过改变终轧温度及轧后冷却速度,研究了终轧温度及轧后冷却速度对力学性能的影响。研究结果表明：采用轧后加速冷却的方法,可以显著细化Q460的铁素体晶粒,从而提高其强韧性能。当冷速从2℃/s提高到3.86℃/s时,铁素体晶粒直径从11.5μm细化到8.33μm。当冷速达到2.96℃/s以上时,Rel≥475MPa,Rm≥600MPa,屈强比为70%-80%。     

FTSR低碳高强钢连续冷却相变和组织细化

用Gleeble-3500热模拟机研究了低碳钢 (%:0.19C、1.15Mn、0.008Mo、0.002Ti、0.032Als) 85 mm FTSR(薄板坯连铸连轧)铸坯在1 000℃以5 s^-1速率变形40%,然后以5℃/s冷却到900℃并以50 s^-1的速率变形30%,再以1～70℃/s冷却到400℃,空冷的连续相转变和组织。结果表明,冷却速度≤20℃/s时连续冷却转变的组织为铁素体和珠光体;冷却速度达30℃/s时,组织中出现少量粒状贝氏体。随冷却速度增加,晶粒尺寸减小,当冷却速度达10℃/s时,钢中的晶粒尺寸≤10μm,当冷却速度≥20℃/s时,钢中晶粒细化程度减弱。     

一种高强Al-Mg-Si-Cu铝合金铸造工艺研究

研究了一种Al-Mg-Si-Cu铝合金Φ310mm圆铸锭的熔铸工艺,通过实际生产同铸造模拟相结合,优化铸造温度、铸造速度、冷却水流量等铸造工艺参数,得到最优值。研究结果表明,当使用优化参数,即铸造温度为680℃～700℃、铸造速度为60mm/min、单根水流量为5m3/h时,铸造成型质量良好,内部成分均匀且低倍晶粒度达到1级。     

细化剂和冷却速率对Al-Mg-Mn合金凝固组织的影响

细化剂含量和冷却速率对凝固过程具有重要影响.分别加入不同含量的Al-3Ti-B晶粒细化剂,研究其对一种Al-Mg-Mn合金晶粒组织的影响.结果表明,随着晶粒细化剂含量的增加,晶粒愈加细小,在本实验范围内当细化剂含量为0.1%Ti时,组织最为均匀细小.采用连续测温的方法,测定了使用不同铸模时,铸锭的冷却速率,并分析了冷却速率对凝固组织的影响.与使用耐火材料铸模相比,使用石墨铸模时,铸锭的冷却速率提高1～2个数量级,铸态组织得到显著细化,平均晶粒尺寸由138μm细化到35μm.     

铌高性能结构钢相变规律的研究

利用MMS-100热／力模拟机,研究了不同冷却速度下铌高性能结构钢奥氏体动态转变规律及不同终轧温度和不同压缩比对显微组织的影响。结果表明：在冷却速度为1～5℃／s得到完全的铁素体和珠光体,且随冷速增大,晶粒明显细化,珠光体细小分散,当冷却速度大于15℃/s时,得到完全贝氏体组织;随变形温度的降低,铁素体晶粒细化,珠光体的球团和片层间距减小,组织的均匀性改善;随变形程度的升高,铁素体体积分数增加,且组织细小均匀。铌裔陛能结构钢终轧后冷却速度应控制在5℃/s左右,终轧温度选择850℃。     

冷却路径对V-Ti微合金钢组织性能的影响

 为了获得较大的沉淀强化增量,采用热模拟试验研究了UFC终冷温度和二阶段冷却速度对一种V Ti微合金钢组织和硬度的影响规律。结果表明,协同控制UFC终冷温度和二阶段冷却速度可显著优化V Ti微合金钢的组织性能。UFC终冷温度为750、700和650 ℃时,获得全铁素体组织的临界二阶段冷却速度分别为1.0、1.0和0.2 ℃/s。UFC终冷温度由750降低至650 ℃时,在二阶段冷却速度为0.2~1.0 ℃/s条件下,可将铁素体晶粒由10.5细化至8.4 μm,二阶段冷却速度为5.0 ℃/s时,可将铁素体晶粒由10.5细化至5.1 μm。在750和700 ℃较高UFC终冷温度条件下,适当提高二阶段冷却速度,在650 ℃较低冷却速度条件下,适当降低二阶段冷却速度,均可有效提高试验钢的维氏硬度,试验钢的最大维氏硬度可达到295HV。     

热变形对0.05C-0.13Nb钢组织和显微硬度的影响

用Thermeeomastor-Z热模拟试验机,研究了0.05C-0.13Nb钢单道次1 000℃、2 s-1形40%和双道次1 000℃、2 s-1变形40% 980℃ 5 s-1变形40%后冷却速度、变形量、原始奥氏体晶粒度和应变速率对组织和显微硬度(HV)的影响.结果表明,冷却速度增加,钢中粒状贝氏体逐渐增多,冷却速度达5℃/s时,贝氏体含量达93%,HV值显著增加;当冷却速度超过5℃/s时,贝氏体岛状组织形貌改变,HV值增加较小;随原始奥氏体晶粒尺寸减小和变形量增大,HV值减小,应变速率对HV值无显著影响.     

冷却工艺对Ti微合金化高强钢组织和硬度的影响

通过热模拟实验,研究了冷却工艺参数对Ti微合金化高强钢组织和硬度的影响。结果表明:当终冷温度为700℃时,随着冷却速度的增大,铁素体和珠光体组织得到了显著细化,实验钢硬度增加;随着终冷温度的降低,多边形铁素体晶粒尺寸呈减小趋势,铁素体和珠光体含量逐渐降低,珠光体片层间距逐渐减小,贝氏体含量增加,相变强化和细晶强化共同作用使得实验钢的硬度逐渐增加;钢中存在少量粗大的TiN和Ti_4C_2S_2粒子,冷却速度由5℃/s增大到30℃/s, TiC粒子的析出数量明显增加,平均尺寸由8.1 nm减小到6.7 nm;终冷温度由700℃降到600℃,第二相粒子TiC的析出数量逐渐减少,平均析出粒子尺寸由6.7 nm减小到5.9 nm。研究结果为Ti微合金化高强钢控制冷却工艺的制定奠定了理论基础。     

相变区控制冷却速度对60Si2MnA钢线材组织的影响

通过热模拟机 Gleeble- 15 0 0对控制冷却过程的模拟 ,研究了相变区冷速对 6 0 Si2 Mn A弹簧钢的组织结构、珠光体量、珠光体片层间距和平均晶粒尺寸的影响 ,结果表明 ,冷速 v≤ 5℃ / s时 ,组织为珠光体 +铁素体 ;v>5℃ / s时 ,有马氏体产生 ;v=3℃ / s时珠光体量达到 85 % ;珠光体片层间距在 v=9～ 11℃ / s时达到较小值 0 .118～ 0 .133μm;在 v=7℃ / s时 ,平均晶粒尺寸达到较小值 2 6 .1μm。综合考虑 ,终轧温度 95 0℃ ,吐丝温度在 870～ 930℃范围内 ,相转变时冷却速度控制在 5℃ / s,产品性能得到明显改善     

低碳钢热轧钢筋再结晶控制轧制与控制冷却实现晶粒细化

低碳钢低的再结晶温度使得其在钢筋的连续轧制过程中可以通过再结晶控制轧制及控制冷却工艺来实现晶粒细化。试验结果表明，成分为0．18C-0．22Si-0．60Mn的低碳碳素钢在850℃或更低温度以较大的变形量变形时，可以获得10～20μm的奥氏体晶粒尺寸；当加以20℃／s或更高的冷却速度冷却时，可以得到4～6μm或更细小的铁素体晶粒尺寸。晶粒细化使得钢筋的力学性能明显提高。     

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)