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1.
利用金相显微镜对某厂生产的预应力钢绞线盘条拉拔断裂样进行分析,根据拉拔断样形貌,分析出预应力钢绞线盘条拉拔断裂影响因素包括成分偏析、盘条表面缺陷、盘条组织、拉拔工艺等,为提出合理的改善措施,提高高碳钢盘条质量提供了便利条件。  相似文献   

2.
《炼钢》2012,28(4)
针对河北钢铁股份有限公司承德分公司生产的ER70S-6钢盘条拉拔过程断丝、强度及硬度偏高、费模具等而影响拉拔性能的问题,对盘条进行分析,并与其他厂家盘条进行对比,认为钢中残余元素含量高、铸坯表面和低倍质量差、轧制缺陷是造成盘条质量差的主要原因。对ER70S-6钢残余元素成分、冶炼和轧制工艺进行了优化研究,使盘条抗拉强度和硬度降低,表面质量得到提高,拉拔性能得到改善。  相似文献   

3.
高海 《炼钢》2012,(4):32-35
针对河北钢铁股份有限公司承德分公司生产的ER70S-6钢盘条拉拔过程断丝、强度及硬度偏高、费模具等而影响拉拔性能的问题,对盘条进行分析,并与其他厂家盘条进行对比,认为钢中残余元素含量高、铸坯表面和低倍质量差、轧制缺陷是造成盘条质量差的主要原因。对ER70S-6钢残余元素成分、冶炼和轧制工艺进行了优化研究,使盘条抗拉强度和硬度降低,表面质量得到提高,拉拔性能得到改善。  相似文献   

4.
70钢盘条拉拔断裂的原因分析   总被引:1,自引:0,他引:1  
70钢盘条在拉拔时发生断裂,经对盘条拉拔工艺和盘条材质进行分析,认为盘条心部存在网状渗碳体是造成拉拔断裂主要原因.  相似文献   

5.
针对硬线钢盘条拉拔φ3mm以下规格细丝时常出现断丝的问题,对盘条进行分析,并与国内其他先进厂家盘条进行质量对比,造成盘条拉拔性能差的原因有钢质大型夹杂、铸坯残余缩孔、化学成分控制波动范围大、盘条S含量及[N]含量高等。对铁水预处理、脱氧、LF精炼及连铸工艺进行了优化研究,盘条质量得到提高,拉拔断丝率明显降低,使硬线钢的盘条品质达到了下游用户拉拔丝的要求。  相似文献   

6.
针对汉钢公司生产的82BΦ12.5mm盘条在研发初期供客户试用的过程中出现了拉拔断裂的问题,通过对82B热轧盘条拉拔断裂原因进行分析,并根据检验分析结果,有针对性地优化了转炉冶炼、LF精炼、连铸、轧制等环节的工艺。经工艺优化后,目前汉钢所生产的82BΦ12.5 mm盘条性能优异,完全满足客户使用要求。  相似文献   

7.
通过对拉拔过程中发生断裂盘条的金相组织,断口形貌进行分析检验,找出65MnT盘条在拉拔过程中产生断裂的原因。给出制定控冷工艺的基本原则,并根据线材厂生产实际进行不同控冷工艺参数的对比试验,改进原控冷工艺,确定了满足65MnTi盘条质量要求的新控冷工艺参数。  相似文献   

8.
82B盘条拉拔脆断及低温脆断是高碳钢盘条的经常发生的问题,对盘条及下游客户拉丝生产造成了严重影响。本文通过对酒钢82B盘条控冷工艺进行研究,结果表明:优化控冷工艺及设备防护可改善盘条内部金相组织及表面质量,减少脆断现象。  相似文献   

9.
张治华  张亭 《包钢科技》2018,44(3):9-12
文章采用金相组织检验以及电镜扫描等方法,对拉拔、绞线过程中产生断裂的SWRH82B盘条进行检验,得出引起断裂的原因主要是心部马氏体和夹杂物的存在。另外,生产加工工艺的不合理也是盘条质量较差的一个重要原因。通过改善生产加工工艺,盘条质量明显改善,拉拔断丝现象减少。  相似文献   

10.
为解决ER50-6钢盘条损伤拉拔模具、焊接飞溅大等问题,对材料成分、强度、表面氧化铁皮等主要影响因素进行了分析。通过优化化学成分,控制成分C≤0.08%;同时优化炼钢工艺和轧钢加热、轧制、控冷工艺等,控制盘条抗拉强度≤530MPa,控制合适的氧化铁皮厚度,解决了焊丝用钢拉拔使用中存在的问题,满足了客户使用性能要求。  相似文献   

11.
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)  相似文献   

12.
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.  相似文献   

13.
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".  相似文献   

14.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
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。  相似文献   

15.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
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。  相似文献   

16.
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.  相似文献   

17.
18.
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.  相似文献   

19.
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。  相似文献   

20.
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.  相似文献   

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