新型超高强度结构钢Q960E组织与性能控制研究

南钢针对新型超高强度结构钢Q960E在线淬火态和回火态组织与性能的关系进行研究。结果表明:在线淬火态钢板淬透性良好,全厚度组织均匀;回火后得到回火板条马氏体、回火板条马氏体+板条贝氏体组织,具有良好的低温韧性和强韧性匹配,强度富余量适中,延伸率14%,-40℃纵向冲击值在100 J以上。     

热处理工艺对EH690级特厚钢板心部组织及性能的影响

针对不同热处理工艺对EH690级特厚钢板心部组织和性能的影响展开研究,结果表明：经过在线淬火+回火处理,钢板心部的强度能够满足性能要求,但冲击韧性极差,显微组织为粗大粒状贝氏体和珠光体的混合组织;一次淬火+回火处理后,强度下降明显,冲击性能有所改善,但是不能满足-40℃低温冲击吸收功≥69 J的要求,存在混晶,组织为粒状贝氏体+少量马氏体;二次淬火+回火处理后,强度整体偏高,冲击功均值满足标准要求,强韧性匹配程度一般,晶粒细化明显,马氏体含量占比增多。通过调整回火温度,最终获得晶粒细小均匀、以高密度位错回火索氏体为主的组织,钢板心部强韧性匹配较好。     

厚规格35CrMo预硬型模具钢板的回火组织与硬度研究

通过扫描电镜的分析手段,研究了莱钢生产35CrMo预硬型模具钢板厚度方向显微组织对硬度分布的影响。结果表明:80mm厚度钢板经过900℃淬火和550~560℃回火后,钢板近表面硬度为HRC32~36,心部硬度超过HRC28,厚度方向硬度波动控制在HRC5以内;120mm厚度钢板经过920℃淬火和570℃回火后,钢板近表面硬度为HRC32~34,心部硬度下降到HRC28~30。回火态钢板表面硬度下降幅度大于心部硬度的下降幅度,钢板近表面处组织中的回火马氏体呈板条状,原始奥氏体被晶界不同取向的板条马氏体分割细化,组织中碳化物呈短棒状,数量相对较少;板厚1/2处组织为回火贝氏体和数量较多的碳化物。随着钢板厚度增加和回火温度升高,显微组织中回火马氏体体积分数逐渐减少,回火贝氏体体积分数逐渐增多,组织中的碳化物析出量逐渐增加,聚集长大趋势明显。     

高强韧性海洋平台用E550钢板生产工艺研究

介绍了E550钢板的主要生产工艺和技术难点,通过理论分析设计了E550的成分体系,采用Thermal-Calc和经验公式,获得了其热力学相图和相变点温度等热力学数据。根据E550的热力学特性,设计了两阶段轧制工艺,精轧的终轧温度控制在再结晶温度附近,利用奥氏体再结晶充分细化晶粒。淬火奥氏体化温度选择为920℃,回火温度设计为630℃,利用碳化物的析出强化效果和缺陷密度变化的位错强化获得良好的强韧性匹配。50 mm厚钢板的淬火态1/4厚度处的微观组织为马氏体,中心的组织为马氏体和少量贝氏体的混合物。回火热处理后,马氏体板条界面减少,碳化物在马氏体板条界面析出,钢板1/4到中心的组织均匀化。30和50 mm厚E550钢板的力学性能达到了船级社标准要求,并有较大的富裕量。热输入能量为15和50 kJ/cm焊接后,钢板具有良好的强度性能,熔合线和热影响区的冲击功较高。     

热处理工艺对高强度耐磨钢性能影响研究

针对采用热轧+淬火+低温回火工艺生产的NM400耐磨钢板,研究了不同温度回火处理对钢板组织、力学性能和耐磨性能的影响。结果表明:耐磨板组织为回火马氏体和残余奥氏体,具有良好的韧性和耐磨性能;低温回火可以改善NM400钢的韧性,经过250℃低温回火处理的钢板综合性能最优。     

屈服强度785 MPa低碳含铜船板钢的组织和性能

 研究了一种屈服强度大于785 MPa的船板钢,测试了其动态连续冷却相变曲线（CCT）,研究了试验钢经控制轧制+直接淬火+回火（DQ- T）工艺处理后的组织性能。结果表明,直接淬火（DQ）钢板组织为板条马氏体（LM）,回火后铜、铌元素呈弥散析出。经500 ℃回火钢板的强度最高,冲击韧性（KV2）最低。钢板经710 ℃回火,其组织为二次马氏体（SLM）+铁素体,屈服强度（Re）为810 MPa,抗拉强度（Rm）为 1 066 MPa,伸长率（A）为17%,在-80 ℃下KV2为97 J,达到最佳强韧性匹配。     

纳米粒子强化含铜双相钢的组织性能关系

 为进一步提高HSLA系列含铜钢的综合力学性能,利用多步骤热处理工艺(QLT工艺:淬火、临界区淬火及回火工艺)在超低碳Ni-Cr-Mo-V-Cu低合金钢中获得了优异的强度及低温韧性匹配(屈服强度895 MPa、抗拉强度950 MPa、-80 ℃冲击韧性188 J)。利用SEM、XRD及TEM等试验方法研究了试验钢在QLT工艺处理后,不同临界区淬火温度下(Ac1~Ac3温度范围内)的双相组织演化规律,阐明了不同临界区淬火温度下的QLT态试样的组织及性能关系。结果表明,QLT态试样的屈服强度与回火二次马氏体体积分数呈二次抛物线关系,抗拉强度与回火二次马氏体体积分数呈线性正相关关系;断裂伸长率则与临界区铁素体含量正相关。临界区淬火温度为720 ℃时的QLT态试样(QL₇₂₀T)表现出优异的强度及低温韧性匹配,其高强度来源于协同析出的纳米级MC(M为铌、钼、钒及钛的任意组合)和铜粒子所强化的回火二次马氏体。QL₇₂₀T态试样优异的低温韧性则由下列因素所致,主要呈片层状的回火二次马氏体及临界区铁素体的平行相间分布而导致的组织细化效应;大量异相界面所导致的脆性渗碳体或合金渗碳体的细化;强度差异较小的回火二次马氏体以及临界区铁素体。     

调质工艺对Q690D钢综合力学性能及组织的影响

 以60mm厚Q690D高强度结构钢板为研究对象,在相同轧制条件下,系统地研究了淬火、回火温度对试验钢综合力学性能及显微组织的影响,并对第二相析出进行理论分析。试验结果表明：随淬火温度升高,试验钢强度升高,韧性下降;随回火温度升高,试验钢强度下降,但韧性明显升高。该钢采用930℃淬火(保温10min)650℃回火(保温40min)的调质热处理工艺具有良好的强韧性匹配,综合力学性能最佳,满足国标GB/T 16270—2009要求。     

热处理及NbV-N微合金化对船板钢组织性能的影响

为了获得一种良好强韧性匹配的390MPa级船板钢,通过NbV-N复合微合金化及不同热处理工艺(正火+回火、淬火+回火),对实验室钢板的室温拉伸、-40℃冲击性能及钢的微观组织、析出相等进行了分析研究。结果表明,钒、铌的添加能细化晶粒,且氮质量分数的增加使得这种细晶效果更为显著,从而使得钢的强韧性,特别是冲击韧性明显提升。相比轧态,正火+回火、淬火+回火热处理后钢的力学性能均有明显提高,特别是低温韧性有明显改善,这得益于回火过程中大量微合金碳氮化物的弥散析出及钢的有效晶粒尺寸的显著细化。     

核电站用SA738Gr.B钢板热处理工艺研究

为满足SA738Gr.B核电站用钢较高的性能要求,在实验室试验的基础上,研究了工业化生产热处理工艺参数对钢显微组织和力学性能的影响。结果表明,钢板淬火时冷却速度5℃/s时,能够避免先共析铁素体的析出;淬火温度较高时,钢板具有更细小和均匀的板条贝氏体;随着淬火加热的保温时间延长,晶粒组织粗化且铁素体含量减少;随着回火温度的升高,晶粒粗化,同时贝氏体含量减少,铁素体含量增多;在工业化生产中,较大淬火水量下钢板的拉伸性能更优;随着回火时间的延长,钢板强度下降而冲击韧性提高。以920℃×2.0 min/mm加热、较高水量的Q2工艺淬火,并采用650℃×1.5min/mm的工艺回火,可使钢板的强韧性达到最佳匹配。     

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。     

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。     

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.     

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。     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.