共查询到20条相似文献,搜索用时 78 毫秒
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概述了我国冷轧管机各设计制造企业的研制现状和主要机型,着重介绍了LG型二辊冷轧管机和LD型多辊冷轧管机的孔型设计方法,对我国冷轧管机未来的发展方向进行了展望,认为高速、长行程,不停机连续上料,生产过程全自动化控制的冷轧管机是发展的大方向。指出我国的冷轧管机正处在更新换代的最佳时机,应把握住时机将我国冷轧管设备的水平推向一个新的高度。 相似文献
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介绍了冷轧薄板的典型冲压成形方式,结合冷轧不锈钢带基本成形性能与冲压性能的关系,探讨了组织、成分、冷轧工艺、表面质量等因素对冷轧奥氏体不锈钢带冲压性能的影响.提出冲压用冷轧奥氏体不锈钢带要适当增加Ni、Cu含量,减少δ铁素体,控制晶粒度,并对冷轧压下率、厚度精度、表面粗糙度、表面缺陷进行控制,以满足冲压要求. 相似文献
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冷轧辊的磨削质量对冷轧铝板带材的表面质量影响甚大,而如何控制轧辊表面质量的资料较少。以我厂1400E四辊不可逆冷轧机组的操作为例,说明冷轧辊磨削质量对铝板带材表面的影响。 相似文献
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详细介绍了德国、原苏联冷轧管机发展概况和有代表性的几种冷轧管机结构特点及性能参数;同时介绍了我国冷轧管机的研究情况,探讨了提高冷轧管机产量和质量的途径。 相似文献
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扫描电镜观察显示鹿茸皮质层是一种由矿化胶原纤维和胶原蛋白基体组成的层状天然生物陶瓷复合材料。观察也发现在鹿茸皮质层中存在许多微孔洞,而起增强作用的羟基磷灰石纤维是迂回地环绕这些孔洞,构成一种矿化胶原纤维迂回绕孔结构。基于观察的结果,建立纤维迂回绕孔结构和纤维非迂回绕孔结构复合材料细观分析模型,分析比较了纤维迂回绕孔结构和纤维非迂回绕孔结构的断裂强度,结果表明纤维迂回绕孔结构的断裂强度明显大于纤维非迂回绕孔结构的断裂强度。基于实验和分析的结果,用碳纤维和环氧树脂进行了仿生纤维迂回绕孔结构复合材料的制备,并对得到的纤维迂回绕孔结构复合材料与纤维非迂回绕孔结构复合材料进行了断裂强度的比较测试。结果显示纤维迂回绕孔结构复合材料的断裂强度明显大于纤维非迂回绕孔结构复合材料的断裂强度。 相似文献
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1 INTRODUCTIONTiAlalloyhaslongbeenconsideredasapromis ingmaterialforhightemperatureapplication ,duetoitsexcellenthightemperature p 相似文献
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To reduce the mass of the mirror, silicon carbide was used as the material and four light-mass structures were designed. The properties of SiC mirror open back structure with triangular cell, open back structure with hexagonal cell, sandwich structure with triangular cell, sandwich structure with hexagonal cell, were analyzed by using finite element method. The results of the static, dynamic, and thermal properties of the four kinds of SiC mirror indicate that the surface figures of the SiC mirrors are all satisfactory with the design requirements. The properties of the mirrors with sandwich structure are better than those with open back structure, except the high cost. And the mirror with triangular cell has better combination properties than the mirror with hexagonal cell. Considering the overall performance and the cost, open back structure with triangular cell is the most suitable for the SiC mirror. 相似文献
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寻求有生命力的大学教育理念 总被引:6,自引:1,他引:5
教育的目的是把每个学生培养成具有快乐生活品质、丰富人性魅力和完善生命观的人。追求有生命力的教育观、一切为了学生生命的发展,应该成为教师的事业理念;塑造鲜活的生命的神圣事业使师生在生命点化生命、人格浸润人格、精神涵养精神、心灵美化心灵中共享生命教育的喜悦。 相似文献
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微织构自润滑表面在油介质中的摩擦学性能 总被引:1,自引:1,他引:0
为探究不同表面处理方式对试样表面摩擦学性能的影响,分别对GCr15试样表面进行激光微织构加工,光滑表面涂抹润滑油,微织构表面填充固体润滑剂,微织构表面涂抹润滑油,微织构表面填充固体润滑剂并涂抹润滑油等不同表面处理方式,在MMW-1A摩擦磨损机上进行摩擦磨损试验。同时改变试验的载荷及转速,探究在不同转速和载荷工况下,不同表面处理方式对试样摩擦因数的影响。结果表明,在干摩擦条件下,试样表面采用微织构处理并填涂固体润滑剂可使摩擦因数较光滑表面降低47.6%;在油介质中,采用微织构处理可使摩擦因数较光滑表面降低4.8%,采用微织构处理并填充固体润滑剂可使摩擦因数较光滑表面降低17.7%。且在油介质中,采用织构化处理和固体润滑结合的表面处理方法,试样摩擦因数随载荷增大而减少且逐渐趋于稳定,但随转速增大而增大。 相似文献
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Investigation on stress corrosion cracking of austenitic steels in cold chloride solutions At ambient temperatures of about 25°C austenitic chromium nickel steels can suffer stress corrosion in media with a concentration of both hydrogen ions and chloride ions exceeding 1 mol/L or in strongly concentrated chloride solutions. With the aid of constant strain rate testing and with U-bend specimens the parameters of this types of corrosion were investigated. Contrary to the situation with the acid solutions, the reproducibility of test results with the concentrated chloride solution was found to be low. The formation of martensite by cold working was found to be essential. The corrosion susceptibility decreases with increasing nickel content. Stress corrosion takes place within small critical potential ranges without a limit to more positive potentials as this is the case of stress corrosion with hot media. These potential ranges are widened with increasing cold working especially in the case of strongly grinding or cyclic loading in the plastic range. Corrosion cracking was observed with solutions of MgCl2, LiCl, with a less amount with NaCl, but not with ZnCl2. The concentration of chloride ions have an effect for solutions with a given kind of salt, but not for different salt solutions. 相似文献
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针对传统电火花沉积技术存在电极制备工艺复杂、涂层存在较多裂纹及孔洞的不足,把WC-8Co粉末置于电极与基体之间的脉冲放电通道内,利用电火花沉积工艺制备了WC-8Co涂层.对比分析了新工艺与传统工艺制备的涂层表面形貌、显微组织及摩擦磨损性能.结果表明,用新工艺制备的涂层表面平整、粗糙度低、组织致密,与基体呈冶金结合.与传统工艺相比,新工艺制备的涂层有良好的耐磨粒磨损性能.用粉末预置法制备涂层能提高电火花沉积效率,适于制备大面积的涂层. 相似文献
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Glass milling is discussed with influences of tool inclination on brittle fracture. Cutting tests are performed to observe surfaces in the up-cut and the down-cut processes with a ball end mill inclined in the feed direction of the cutter. Brittle fracture occurs in the down-cut process at high feed rates. Then the machined surfaces in cutting with the ball end mills tilted in the vertical plane with respect to the feed direction are associated with those of the up-cut and the down-cut processes. The cutting forces are also measured to discuss brittle fracture with the change of the undeformed chip thickness. The scratches on the surface finished with the tilted ball end mill are shown in an analytical model with a notched edge shape. The maximum feed rates at which brittle fracture does not occur are shown with the tool inclination in the cutting tests. 相似文献