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1.
陈颜堂  芮晓龙 《钢铁》2007,42(6):38-41
经过系列技术攻关,改进了武钢专用钢板冶炼及连铸过程中一些工艺,形成了一套自主操作技术模式,生产的微合金化低合金高强钢中杂质含量显著降低,钢板性能稳定性明显提高.利用武钢新改进的冶炼技术研制了一种600 MPa级低焊接裂纹敏感性高能量输入焊接水电站压力钢管用钢,研究了该钢的力学性能、微观组织结构以及焊接粗晶热影响区(CGHAZ)的组织特征及力学性能.结果表明,研制的新钢种集高强度、高韧性、优异的焊接性能于一体,且能承受大线能量焊接,焊前不预热,焊后不热处理.CGHAZ中弥散分布的复合氧化物夹杂促使针状铁素体的形成,提高了CGHAZ的力学性能.  相似文献   

2.
大线能量低焊接裂纹敏感性钢性能及组织研究   总被引:9,自引:1,他引:8  
设计并研究了一种60kg级大线能量低焊接裂纹敏感性钢,试验结果表明,对本研究钢种而言,Cr和B不是理想的合金化元素,钢中Ti/N比接近理想化学配比时组织细化,提高了钢材的强度和韧性,试验钢理论的使用组织为回火索氏体。  相似文献   

3.
非调质低焊接裂纹敏感性钢WDB620研究与开发   总被引:8,自引:0,他引:8  
常跃峰  谢良法  姚连登  赵文忠 《钢铁》2003,38(11):52-57
按照CF62钢的技术要求,设计了一种620MPa级低焊接裂纹敏感性钢。采用微合金化结合控轧控冷工艺,免去了淬火工序,以晶粒细化、沉淀强化、位错强化和贝氏体组织强化为主要手段,并对钢的可焊性进行了评价。产品已应用于水电站压力钢管系统及108t电动轮自卸车。  相似文献   

4.
杨汉  王西霞  曲锦波 《钢铁》2013,48(12):80-84
 分析了在控轧、控轧加回火、调质等不同工艺条件下,硼对低焊接裂纹敏感性钢显微组织和力学性能的影响。结果表明,硼抑制先共析铁素体形成,提高淬透性,在控轧工艺下含硼钢形成粗大的贝氏体和马氏体组织,并保留了原始奥氏体晶界;调质工艺得到回火索氏体组织,但含硼钢的大角度晶界比例与无硼钢相比较低。硼在强度上的作用显著,上述3种工艺下含硼钢的抗拉强度分别比无硼钢高300, 214, 101MPa,屈服强度分别高320,259,144MPa,但伸长率和冲击韧性均有所降低。无硼钢在调质工艺下、含硼钢在控轧加回火工艺下具有较好的强韧性匹配。  相似文献   

5.
用铁研试验法,研究了符合我国资源特点的复合微合金化低碳SiMn3型贝氏体高强钢的焊接裂纹敏感性。结果表明,该类钢即使在不预热的条件下施焊,也不会出现冷裂纹。这与其HAZ过热区具有板条贝氏体加低碳马氏体混合组织有关。  相似文献   

6.
通过焊接热影响区连续冷却相变(Simulated Heat Affected Zone Continuous Cooling Transformation,SH-CCT)曲线、斜Y型坡口焊接裂纹实验,研究了一种1300 MPa级超高强钢的焊接热影响区连续冷却相变规律和焊接裂纹敏感性.结果表明:实验钢模拟粗晶区的SH-C...  相似文献   

7.
郭桐  叶建军  崔强 《宽厚板》2006,12(6):17-22
本文通过对厚度60kg级50mm厚以上调质型高强钢WDB620钢板的3种成分设计和各成分下谓质工艺对钢板力学蜂能影响的对比性研究,较合理地确定了调质型高强钢WDB620钢板的成分设计和调质工艺,使该钢板在保证低焊接裂纹敏感性的前提下,仍具有良好的淬透性,各项性能指标仍能满足60kg级水电用特厚钢板的要求,并且使该钢板的最大生产厚度达到100mm。  相似文献   

8.
刘丹  罗登  肖强健  王小军 《钢铁研究》2011,39(2):23-26,37
介绍了低焊接裂纹敏感性07MnCrMoVR钢(简称X610CF钢)力学性能、组织结构及工程应用.该钢具有优异的焊接性能和低温韧性;板厚不大于50 mm的钢板焊前不预热或稍加预热而不产生焊接冷裂纹,是制造大型压力容器(特别是低温和常温球罐)、水电站压力钢管的理想用材.  相似文献   

9.
《宽厚板》2004,10(2):F002-F002,F003
WDB620是舞钢生产的压力钢管用低焊接裂纹敏感性高强度钢板,采用国际低合金高强度钢的先进设计思想和研究成果,运用微合金化原理和控制轧制工艺开发的超低碳贝氏体钢。WDB620钢具有理想的强度、塑韧性指标及优良的焊接性能,达到或超过了同类进口产品的水平,广泛应用于水电站压  相似文献   

10.
非调质低焊接冷裂纹敏感性钢WDB620的试制   总被引:2,自引:0,他引:2  
按照焊接无裂纹钢(CF钢)的技术要求,试制了620MPa级非调质低焊接冷裂纹敏感性钢。该钢以晶粒细化,沉淀强化和贝氏体组织强化为主要手段并以微量Ti处理改善焊接热影响区韧性,具有良好的综合机械性能和焊接性能。  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.
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   

19.
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   

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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