N对15MnVq桥梁钢组织和性能的影响

采用VN合金和V合金,熔炼15MnVNq钢和15MnVq钢.从这两种钢的显微组织、硬度、强度、冲击性能和析出相等方面对二者进行对比研究,分析N对15MnVq组织及性能的影响.结果表明,N的加入对15MnVq钢晶粒细化和力学性能的提高均有显著的效果.     

Si含量对超超临界汽轮机转子钢30Cr2Ni4MoV组织和性能的影响

30Cr2Ni4MoV钢(%:0.15～0.16C、0.03～0.45Si、0.12～0.14Mn、0.005P、0.005～0.006S、1.62～1.72Cr、3.60～3.63Ni、0.52～0.53Mo、0.07V、≤0.005A1)由10kg真空感应炉冶炼,锻后经930℃空冷+900℃空冷+640℃空冷处理,再经850℃水淬+600℃回火调质处理。试验结果表明,当钢中的Si含量由0.03%增加至0.45%时,钢中马氏体量增加,晶粒更为粗大;钢的抗拉和屈服强度分别从922～936 MPa和868～873 MPa增至1015～1028 MPa和950～959 MPa,但平均冲击功由205 J降至154 J。     

氮含量对500E抗震钢筋20MnVN组织和性能的影响

研究的Φ5 mm 500E抗震钢筋20MnVN（/%:0.19~0.20C,0.23~0.26Si,1.26~1.31Mn,0.016~0.023P,0.006~0.012S,0.10~0.11V,0.0038~0.0163N）的生产流程为50t顶底复吹转炉-LF-160 mm×160 mm方坯连铸-控轧控冷工艺。结果表明,随着钢中氮含量增加,500E 20MnVN钢盘条拉伸断口的韧窝变深,口径增大,组织中铁素体含量由63.6%增加至74.8%;增加氮含量有助于20MnVN钢盘条屈服强度、抗拉强度和伸长率的提高,当氮含量由0.0038%增加到0.0163%时,该钢屈服强度、抗拉强度和伸长率分别由513 MPa、650 MPa和10.5%提高到571 MPa、703 MPa和13.0%。分析了V-N微合金化和V（C,N）析出的强韧化机理。     

非调质钢50MnSiV新能源汽车电机轴的开发

非调质钢50MnSiV(/%:0. 50C,0.52S,1.20Mn,0.010P,0.025S,0.15Cr,0.10V,0.015Ti,0.015N)制造的新能源汽车电机轴,省去传统调质钢20CrMnTiH渗碳热处理和矫正精整工序,不仅可提高材料95%利用率和2天交货周期,还可以降低25%成本。50MnSiV钢抗拉强度1100 MPa、屈服强度858 MPa、冲击功48J。其静扭扭矩(4697 Nm)、疲劳寿命(±1600 Nm双向扭转12万次、±1400 Nm双向扭转27万次)较渗碳20CrMnTiH钢提高了27%和93%～140%,并且其性能指标和8万公里的路试结果均满足电机轴的技术要求。     

16Mn钢V(N)微合金化在大规格高强度角钢生产中的应用

大规格角钢主要用于铁塔和建筑结构中。唐钢过去用16Mn钢生产Q345级别角钢，因供轧制用钢的内控标准化学成分窄(T16Mn钢％：0．18～0．20C，1．35～1．55Mn，Ceq≥0．41)，致使供轧率仅为30％。通过V-N微合金化，开发了T16MnV(N)钢(％：0．14～0．20C，1．30～1．60Mn，0．05～0．09V，0．009～0．018N)，V(N)微合金化显著提高了该钢的力学性能：σb520～625MPa，σs395～465MPa，δ5 24％～28％，冲击功43～96J，并取得较高的经济效益。     

600 MPa低硅Nb-Ti微合金化优质3.5 mm热轧双相钢板的开发

通过真空感应炉熔炼和浇铸的50 kg锭锻成40 mm×150 mm坯和热轧成10 mm板以及热模拟试验研究了开发的低硅Nb-Ti微合金化双相钢(/%:0.082C,0.15Si,1.20Mn,0.010P,0.002S,0.020Nb,0.015Ti,0.045Al,0.0035N)静态和动态连续冷却转变(CCT)曲线、组织(11%马氏体+89%铁素体)和力学性能(抗拉强度682 MPa)。并通过铁水脱硫-260 t BOF-LF-RH-230 mm×1300 mm连铸-热轧工艺试制了低硅双相钢(/%:0.075C,0.15Si,1.16Mn,0.012P,0.003S,0.016Nb,0.015Ti,0.033Al,0.0043N)3.5mm板。结果表明,精轧出口温度810℃,水冷至700℃,空冷4.5 s,卷取温度150℃时,该钢的组织为15%马氏体+85%铁素体,晶粒度12~12.5级,抗拉强度672~692 MPa,伸长率24.0%~28.5%,屈强比0.65~0.67,钢板冲压成塑性能优良,制造的轿车轮辐弯曲疲劳性能15×10⁴次。     

V含量对高氮20MnSi钢自然时效性能的影响

试验钢（/%:0.22C,1.46~1.66Mn,0.45~0.58Si,0.011~0.013S,0.010~0.012P,0.014~0.047V,0.040~0.044N）由真空感应炉冶炼,浇铸成10 kg锭,锻成25 mm×25 mm坯,并进行870℃ 40 min空冷热处理,经180天自然时效后,观察该钢的组织和测试其力学性能。结果表明,自然时效后高氮20MnSi螺纹钢晶粒变细小,晶粒尺寸为0.8~6μm,带状组织消失,因V（CN）析出,钢的屈服强度提高25~93 MPa,抗拉强度提高17~157 MPa,伸长率由9%~15%提高至26.0%~31.5%,并且自然时效后试验钢的脆性区消失。     

Mo对TMCP工艺轧制EH460高强度船体钢组织和性能的影响

试验用EH460钢(/%:0.06~0.08C,0.20~0.33Si,1.51~1.52Mn,0.003~0.013P,0.002S,0~0.18Mo,0.34~0.36Ni,0.04~0.05Nb,0.05~0.06V,0.013~0.015Ti,0.006~0.026Als)300 mm铸坯由Φ550 mm轧机轧制成60 mm钢板,终轧温度798~817℃,冷却速率5~20℃/s。研究了不含Mo和含0.18%Mo对该钢组织和力学性能的影响。实验结果表明,当冷却速率为15℃时,不含Mo钢抗拉强度645~655 MPa,-40℃冲击功168~200 J,含0.18%Mo钢抗拉强度677~679 MPa,-40℃冲击功48~64 J;对于高强度船板钢EH460,采用含Mo钢,可以提高钢板强度,达到船级社对其强度要求(屈服强度≥460 MPa,抗拉强度570~720 MPa,-40℃冲击功≥46 J),但含较高Mo钢的冲击功降低较多,因此,在实际生产中,高强度船板钢EH460中的Mo含量,宜≤0.15%。     

空冷低碳贝氏体钢DB590的组织和性能

试验用空冷低碳贝氏体钢DB590(%:0.06C、0.92Mn、0.49Mo、0.65Cr、0.02Nb、0.08V、0.001 0B)由50 kg真空感应炉熔炼、铸成22 kg锭、锻成(mm)100×100×150钢坯,并控制轧成16 mm板,空冷。通过Gleeble 1500热模拟机得出该钢的CCT曲线。DB590钢轧后空冷(3℃/s)的组织为贝氏体+铁素体基体,钢板的抗拉强度645 MPa,屈服强度471 MPa,伸长率32%,0℃冲击功94 J以及优良的冷弯性能。     

Ti-Nb微合金化对低碳高强度钢组织和性能的影响

0.153Ti-0.038Nb和0.080Ti-0.062Nb两种Ti-Nb微合金化低碳钢(/%:0.061～0.075C、0.22Si、1.76～1.77Mn、0.002～0.003S、0.006P、0.003Als、0.003 8～0.004 2N、0.004 0～0.004 5O)由50 kg真空感应炉冶炼,轧成10 mm板,终轧温度880℃,水冷至630℃。试验结果表明,两种Ti-Nb微合金化钢的析出物均为(Nb,Ti)(C,N)复合析出物;当Ti含量由0.080%增加至0.153%,同时Nb含量由0.062%降至0.038%时,钢屈服和抗拉强度分别从558 MPa和653 MPa提高至633 MPa和756 MPa,屈强比、伸长率和断面收缩率变化较小。表明,添加Ti代替部分Nb进行复合微合金化可提高钢材强度,降低生产成本。     

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.