大厚度P20高合金模具钢复合轧制工艺开发与研究

采用预热+真空焊接工艺,将2块(395×2000×2980) mm规格高Cr合金模具钢P20连铸坯进行焊接复合,通过合理的加热、轧制、热处理工艺,成功开发出厚度240 mm的预硬化模具钢P20,复合界面良好,硬度HRC28～HRC32,符合GB/T 2970-2016标准Ⅰ级探伤要求,使P20大厚度高合金模具钢复合轧制工艺从实验室走向工业化应用.     

厚规格合金模具板探伤不合格原因分析及改进

针对厚规格合金模具板探伤不合格问题,采用酸洗低倍、金相、电子探针等手段对缺陷试样进行了分析,找出了钢板探伤不合格的原因,并制定了相应的改进措施.结果表明:铸坯中心疏松是钢板探伤不合格的原因,通过从提高钢液补缩能力和铸坯在轧制过程中的变形渗透两方面入手,改善了铸坯中心疏松,提高了钢板探伤合格率.     

Q345E-Z25钢探伤不合格原因分析及改进措施

通过成分分析、低倍、金相、扫描电镜及轧制数据的分析,找出特厚规格的Q345E-Z25钢超声波探伤不合格的影响因素有偏析、夹杂物、心部裂纹等。通过加强铁水脱硫、RH脱氢、缓冷钢坯、加大压下率、钢板缓冷等工艺措施,改善钢板内部质量,特厚Z向钢板的超声波探伤合格率由90.3%提升到99.5%以上。     

厚规格X70管线钢板探伤不合原因分析及改进措施

针对济钢生产厚规格X70管线钢板探伤不合的原因,利用金相显微镜、扫描电镜以及能谱仪等检测手段进行显微组织和夹杂物分析.结果表明,中心偏析、组织夹杂物以及同时存在的Nb大型化合物是造成探伤不合的主要原因,采取改善钢水纯净度、延长板坯加热时间和调整连铸、轧制工艺等措施可以提高X70管线钢板的探伤合格率.     

高炉炉壳用特厚钢板LK490C探伤不合原因分析

分析得出了济钢厚规格LK490C钢板探伤不合的主要原因是由于钢板严重的中心偏析带附近出现的细小裂纹所致。通过控制钢中P、S等有害元素含量,采用铸坯及钢板缓冷工艺,并适当提高轧制道次压下量,使得钢板内部质量有了明显改善,保证了钢板的探伤合格率。     

提高模具钢3.1 t锭轧制成材率的优化设计与生产实践

成材率是模具钢用轧制锭生产中需要考虑的重要因素。对钢厂原有3.0 t模具钢用轧制锭进行重新设计与优化，并使用Procast模拟软件对其凝固过程的温度场、全凝时间和内部缺陷进行了模拟计算，旨在保证质量的前提下提高成材率。研究结果表明，新设计3.1 t钢锭的全凝时间为1.78 h，原有3.0 t锭型全凝时间为2.03 h，全凝时间缩短了12.32%，钢锭内部质量良好。在涵盖现有轧制规格和不增加轧制道次的前提下，锭型数量由5个减少到4个。采用40 t EAF-LF-VD模铸工艺路线对新设计的3.1 t钢锭进行小批量生产，初轧后满足GB/T4162-2008 B级探伤规格。锭型优化后的的平均成材率为83.76%，原锭型的平均成材率为78.71%，平均成材率比原来提高5.05%。     

韶钢3450mm中厚板生产线厚规格钢板不平度缺陷控制研究

针对韶钢3 450 mm中厚板生产线轧制厚规格钢板生产过程中出现的不平度缺陷问题,通过现场跟踪,分别从轧制、快速冷却和矫直工艺等方面对其产生原因进行深入分析,找出了各个工序对厚规格钢板不平度缺陷问题的影响因素,在此基础上制定了相应的工艺措施,并在各个工序上机应用,取得明显效果。生产线厚规格钢板的不平度缺陷率由6%以上降低到3%以下,大大减少了不平度缺陷率高带来的订单制造周期长等问题,创造了较为显著的经济效益。     

2.3t铸锭高合金冷作模具钢轧制开坯工艺实践

阐述了高合金莱氏体冷作模具钢2.3t铸锭轧制开坯的工艺开发过程。通过热模试验机实测Cr12MoV在高温状态的抗拉强度和断面收缩率,分析确定了2.3t铸锭高合金莱氏体冷作模具钢脆性铸态组织轧制的温度区域。采取了控制轧制温度、控制变形量等方法,制定了相应的初轧加热工艺制度和初轧机压下规程及轧制方法,确认初轧具备2.3t铸锭Cr12MoV、X210CrW12轧制生产的可行性,实现规模化轧制生产,提高了生产效能,较大幅度地降低了生产成本,且突破高合金莱氏体冷作模具钢惟有小于等于1.2t铸锭组织生产的传统模式。     

提高厚规格钢板探伤不合的措施

规格钢板一般要求以探伤或探伤＋热处理状态交货。但生产的厚规格钢板探伤容易不合，且在大于50mm以上的特厚钢板现象更明显。探伤的主要缺陷有点密、长条、裂纹、面积缺陷及分层性缺陷。分析认为：钢板的疏松、偏析、废金属夹杂、气体及轧制生产中的不标准操作都可能导致探伤不合。提高的措施主要有：     

提高厚规格钢板探伤合格率的研究

对厚规格探伤不合格钢板通过低倍检测、金相及扫描电镜、能谱分析等检测方法进行分析,找出了厚规格钢板探伤不合格的主要原因是非金属夹杂物、中心偏析、分层及疏松.通过采取强化精练控制、铸坯下线缓冷、高温大压下等针对性措施,使探伤合格率提高到90%以上.     

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。     

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。     

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.     

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.