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1.
 为满足用户对钢中磷含量的要求,攀钢采用“双渣法”转炉脱磷工艺开展脱磷试验,并根据生产条件和转炉工艺特点考察转炉脱磷专用氧枪的实际使用效果。试验中,转炉工艺冶炼前期低温脱磷,后期脱碳升温,吹炼前期采用低供氧强度脱磷喷枪,倒渣时切换为常规吹炼喷枪。在吹炼脱磷前期结束扒渣后,熔池中的w([P])下降至0040%以下,脱磷率为47.9%。在试验终点钢水中的w([P])均在0.010%以下,波动范围在0.006%~0.010%,w([P])的平均值是0.0081%。终点脱磷率波动范围是84.4%~92%,平均值是88.3%。  相似文献   

2.
通过对转炉前期倒渣时机和吹炼工艺参数的研究,开发了一种减少渣量的转炉炼钢工艺.该工艺的转炉吹炼过程分2个阶段,分别是脱磷期和脱碳期,脱磷期结束后倒除部分富磷渣,然后进行小渣量脱碳,吹炼终点保留脱碳渣用以下一炉脱磷.实践结果表明:与常规冶炼工艺相比,减少渣量操作工艺的转炉石灰消耗由26 kg/t降至17 kg/t以下,轻烧白云石消耗由13kg/t减少到9 kg/t以下,降低了转炉生产成本;吹炼终点钢水w(P)控制在0.0080%~0.018 2%,平均为0.012 6%.  相似文献   

3.
《炼钢》2017,(6)
结合复吹转炉脱磷原理,针对鞍钢股份有限公司鲅鱼圈分公司炼钢部铁水平均w(P)高达0.12%的现状,综合考虑设备布置等因素,自主开发了复吹转炉的两炉法(脱磷炉+脱碳炉)冶炼极低磷钢种技术。在应用实践中,通过优化脱磷炉和脱碳炉的两炉法脱磷工艺参数,实现了深脱磷的目的。脱磷炉脱磷率高达85%,半钢平均w(P)=0.018%;脱碳炉冶炼终点钢水平均w(P)=0.001 2%;成品钢中平均w(P)0.002 0%,实现了极低磷钢的批量稳定生产。  相似文献   

4.
王海奇  包燕平 《特殊钢》2010,31(6):28-31
以实际生产数据为依据,分析研究涟钢1座100 t顶底复吹转炉冶炼低碳钢08Al(%:≤0.08C、0.17~0.37Si、0.25~0.65Mn、≤0.030P、≤0.030S、0.015~0.65Als)的工艺。发现其冶炼后期底吹强度足,导致部分钢水过氧化,实际终点碳氧浓度积与理论的平衡值有一定偏差;转炉终渣碱度在4~5时,磷、硫在渣-钢间的分配系数最大,脱磷、脱硫效果最好,其终点[C]高,(FeO)低,炉渣氧化性低,不利于脱磷但利于脱硫;冶炼终点钢水温度越低,[C]越高,钢水、炉渣氧化性越低,钢水中残锰含量越高。  相似文献   

5.
 在100t顶吹、180t复吹及260t复吹转炉上研究了双渣法深脱磷规律。通过工业性试验,研究不同吹炼时期冶炼特点,分析吹炼过程需要控制的原料及工艺制度等关键措施,研究结果表明:控制倒炉温度、碱度、渣中w((FeO))及熔渣流动性等因素均是取得良好脱磷效果的重要保证。应用双渣法深脱磷生产试验取得了100t顶吹转炉出钢w([P])平均达到63×10-6,180t复吹转炉w([P])达到51×10-6,260t复吹转炉w([P])达到62×10-6的实绩。  相似文献   

6.
阐述了脱磷炉相关工艺研究以及与常规转炉冶炼时的主要技术指标对比情况。主要工艺有少渣高效冶炼工艺、底吹系统优化,底吹深脱磷工艺、底吹可视化工艺,转炉终点静止脱碳工艺。技术指标对比分析结果显示:脱磷炉终点平均磷含量为O.014%,常规转炉终点平均磷含量为0.019%,脱磷炉脱磷效果明显;脱磷炉石灰消耗控制在41.45kg/t,常规转炉石灰消耗控制在53.27kg/t;脱磷炉终点渣中平均TFe含量为11.73%,常规转炉终点渣中平均TFe含量为14.38%,脱磷炉金属收得率高;脱磷炉平均终点钢水残锰0.102%,常规转炉平均出钢残锰0.075%,脱磷炉合金消耗少;脱磷炉平均喷溅渣量为3.93kg/t,常规转炉平均喷溅渣量为13.23kg/t,脱磷炉过程控制平稳,金属损耗少;脱磷炉冶炼钢水终点碳氧积为0.002129,常规转炉冶炼钢水终点平均碳氧积为0.002659。脱磷炉控制水平较好。  相似文献   

7.
在分析脱磷机理及炉渣物相的基础上,以首秦公司100t转炉脱磷生产为例,研究了转炉双联脱磷、脱磷脱碳枪脱磷、转炉冶炼加出钢脱磷、三渣法脱磷等几种工艺的转炉深脱磷能力。实践表明:转炉冶炼加出钢脱磷工艺脱磷率最高,达到97.5%,脱磷后w(P)能达到0.002%;三渣法脱磷符合生产条件,在铁水w(P)达到0.150%的条件下,脱磷率达到96.7%,能有效降低冶炼成本。  相似文献   

8.
《特殊钢》2017,(6)
针对转炉终点钢水磷含量高且波动大的问题,对钢水深脱磷控制难点及影响脱磷的因素进行了分析,提出了采用"双渣高拉碳放渣"的深脱磷工艺路线;通过优化造渣制度、供氧和底吹气制度、枪位控制和终点控制等脱磷工艺,9炉34CrMo4钢的冶炼结果表明,钢水脱磷率达84.6%,终点渣-钢磷分配比L_p达到90.1,实现了转炉终点钢水[P]≤0.006%的稳定控制,并通过采用滑板挡渣及顶渣改制等减少回磷的技术措施,具备了批量生产磷含量小于0.010%的低磷钢种的能力。  相似文献   

9.
在中频感应炉上模拟转炉后期钢水条件进行实验,研究造渣制度对转炉双渣脱磷工艺后期深脱磷的影响.结果表明:碱度和渣量是影响深脱磷的两个主要因素;在钢水w(P)约0.022 %,炉渣w(FeO)=25.0 %~30.0 %时,使用碱度3.2~4.0,渣量6.2~8.4 kg/t的炉渣,可获得82 %以上的脱磷率及将钢水w(P)脱至0.003 0 %以下,最低可达0.000 5 %.  相似文献   

10.
通过对转炉脱磷影响因素的分析及脱磷工艺优化试验,采取前中期快速脱磷期双渣操作、强化过程温度控制、终点前采用高拉补吹、控制终点磷等优化措施,既可以提高脱磷效率又能避免钢水过氧化,减缓对炉衬的侵蚀,实现了冶炼转炉终点磷的大幅度降低,转炉冶炼终点P≤60×10~(-6)、成品P≤80×10~(-6)的比例达90%。满足了提高低磷钢生产量的需求。  相似文献   

11.
12.
Two studies investigated the role of expressive vocal behavior (specifically, speech rate and loudness) in fear and anxiety and in sadness and depression. In the 1st study, participants spoke about personally experienced fear and anxiety-arousing and neutral events using 3 different voice styles: fast and loud, normal, and slow and soft. In the 2nd study, participants spoke about personally experienced sad or depressing and neutral events using the same 3 voice styles. In both studies, the participants' highest levels of subjective affective and cardiovascular (CV) arousal occurred when they spoke about the emotional events in a mood-congruent voice style: fast and loud in the case of fear and anxiety, and slow and soft in the case of sadness or depression. Mood-incongruent voice styles canceled the heightened levels of CV arousal normally associated with these negative emotions. The voice-style manipulation had no significant effect on the participants' levels of CV arousal during the neutral discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
Despite the use of multimodal therapy, higher-grade glioma is still uniformly fatal in the adult population. There is a considerable difference between the length of survival in each given patient, even within the same tumor type and malignancy grade group, suggesting that there are factors that might differentially influence outcome. To identify such factors, 107 patients with anaplastic or malignant glioma were retrospectively investigated. Clinical parameters and paraclinical data on the p53, mdm2, and EGFR genes at the DNA or protein level were evaluated by univariate analysis and Cox proportional hazards regression modeling. Kaplan-Meier survival estimation demonstrated that immunohistochemical positivity for mdm2 protein in patients with anaplastic astrocytoma or with glioblastoma multiforme was associated with a shorter survival time (p = 0.02). P53 gene mutations and immunopositivity for the epidermal growth factor receptor (EGFR) protein were not significantly related to poor prognosis. The Cox proportional hazards model revealed immunohistochemical positivity for p53, mdm2, or for both of them, the presence of postoperative irradiation, and the extent of surgical resection of tumor to be variables significantly associated with prolonged survival. EGFR overexpression, age over 60 years, and Karnofsky performance score below 40 points did not significantly shorten survival time. In conclusion, the present study identified immunohistochemically detected mdm2-protein overexpression as a statistically significant negative prognostic parameter in patients bearing anaplastic or malignant glioma. Association analysis of variables revealed a possible correlation between mdm2 and p53, which is also consistent with the biological interaction mode of both proteins in vivo.  相似文献   

14.
BACKGROUND: As aging research increasingly reflects an effort to dissociate true time-driven changes from those that can be improved, sexuality in later life remains largely unexplored. Several problems are evident. There is a lack of normative data, a lack of a conceptual framework relating to the biology, psychology, and sociology of sex, and an attitudinal resistance that obscures the entire topic. METHODS: We conducted a three-part instructional series on major topics involved with sexuality and aging. We surveyed our group of attendees (n 158, average age 68 for males, 65 for females) before and after the series. RESULTS: A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age. Yet, a substantially decreased involvement was reported from 10 years earlier. Despite current activities, people of both sexes wished they were participating even more than they currently were. Impotency was identified as the major negative feature for the men; relationship problems were for the women. A questionnaire 6 months after the series reported improved sexual attitudes, but no change in sexual activities from the earlier survey. CONCLUSION: Sexuality is a major quality-of-life issue which persists into old age. Our study showed that the usual sexual practices reported by our group were not considered by them to be ideal. The intervention of this instructional series provided improved sexual attitudes but not performance. Additional studies are encouraged.  相似文献   

15.
Spondylolysis and spondylolisthesis occur predominantly in the lower lumbar spine. Besides congenital defects such as predisposition of spondylolysis the correlation between competitive sports activities and an increased incidence of spondylolysis is proved. In early stages, complete healing can be achieved by conservative treatment (abstinence from sports activities for 3 months, orthesis). Persistence of pain, neurologic symptoms and progression of vertebral slipping are indications for operative treatment (reconstruction of the isthmus, dorso-ventral spondylodesis). The exercise tolerance depends on the extent of instability, progression of vertebral slipping and clinical symptoms. The limits of exercise tolerance vary among the individual athletes and require the decision of the physician. Backstroke swimming, abdominal and back muscle strengthening exercises, and types of sport involving smooth movements are advisable. Sports education in school is possible without restriction in patients with stable spondylolysis and in those with spondylolisthesis without unfavourable concomitant factors.  相似文献   

16.
OBJECTIVE: To test the validity of Benjamin Franklin's maxim "early to bed and early to rise makes a man healthy, wealthy, and wise." DESIGN: Cross sectional analysis of sleeping patterns in a nationally representative group of elderly people, and longitudinal investigation of mortality. SETTING: Eight areas in Britain (five in England, two in Scotland, and one in Wales). SUBJECTS: 1229 men and women aged 65 and over who in 1973-4 had taken part in a survey funded by the Department of Health and Social Security and for whom data on sleeping patterns, health, socioeconomic circumstances, and cognitive function had been recorded. MAIN OUTCOME MEASURES: Self reported income, access to a car, standard of accommodation, performance on a test of cognitive function, state of health and mortality during 23 years of follow up. RESULTS: 356 people (29%) were defined as larks (to bed before 11 pm and up before 8 am) and 318 (26%) were defined as owls (to bed at or after 11 pm and up at or after 8 am). There was no indication that larks were richer than those with other sleeping patterns. On the contrary, owls had the largest mean income and were more likely to have access to a car. There was also no evidence that larks were superior to those with other sleeping patterns with regard to their cognitive performance or their state of health. Both larks and owls had a slightly reduced risk of death compared with the rest of the study sample, but this was accounted for by the fact that they spent less time in bed at night. In the study sample as a whole, longer periods of time in bed were associated with increased mortality. After adjustment for age, sex, the presence of illness, and other risk factors, people who spent 12 or more hours in bed had a relative risk of death of 1.7 (1.2 to 2.5) compared with those who were in bed for 9 hours. The lowest risk occurred in people who spent 8 hours in bed (adjusted relative risk 0.8; 0.7 to 1.0). CONCLUSION: These findings do not support Franklin's claim. A "late to bed and late to rise" lifestyle does not seem to lead to socioeconomic, cognitive, or health disadvantage, but a longer time spent in bed may be associated with increased mortality.  相似文献   

17.
Mechanical allodynia (MA) following hand injury is a well-documented clinical problem. The purpose of this pilot study was to examine the relationship between hand MA and the upper limb tension test (ULTT). The ULTT mechanically stresses the neural structures from the C5/6/7 neural foramina to the median nerve distally. This study examined 29 subjects with unilateral hand MA before and after a 2-week neural self-mobilization programme. There was a significant difference between the subjects' affected and unaffected sides when tested using the ULTT, both in reproduction of symptoms and in reduced range of motion of the ULTT. Following the self-mobilization program, there was an improvement in the range of the ULTT, and subjects reported a reduction in their symptoms. Complete recovery was not obtained in all cases. The results of this study suggest that the ULTT is a useful tool both in assessment and treatment of subjects with hand MA.  相似文献   

18.
根据深云立交桥梁的检测结果,对该桥目前的整体状况、工作状态,及其使用情况做出综合评价,对桥的病害原因进行了分析,并提出合理的加固方案。  相似文献   

19.
众所周知,国际单位制物质的量采用摩尔(mol)表示,近几年出版的给排水专业书籍,为了与国际单位制接轨,逐渐将摩尔的使用频率不断提高,被给排水技术人员广泛应用的新版给排水设计手册,将表示物质浓度的单位“当量/升”或“毫克当量/升”.改为mol/l或mmol/l,虽然编者对其基本单元定义作了说明,但在实际运用上仍会出现误解,  相似文献   

20.
劳伦斯小说《儿子与情人》一个鲜明的语言特色就是标准英语和当地方言频繁的语码转换。莫瑞尔用方言来对抗妻子,而妻子坚持用标准英语,偶尔也用方言来讽刺、挖苦丈夫。语码转换反映了劳伦斯男女二元对立的哲学思想。  相似文献   

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