排序方式: 共有49条查询结果,搜索用时 15 毫秒
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为了减轻轧件头部翘曲给轧制过程带来的影响,根据现场轧制工艺,采用弹塑性有限元法建立了三维非对称轧制有限元模型。利用该模型分析热轧板带钢生产过程中轧件头部翘曲的产生机理,并研究了不同轧制工艺下的辊速比、上下表面温差、不同摩擦系数对轧件头部翘曲的影响规律。结果表明,随着压下量的增大,轧件头部翘曲量的增大趋势减缓,采用不同的配辊方案(异径比)可控制其头部翘曲的现象。 相似文献
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SPAH钢是一种耐候钢,由于它具有良好的抗大气腐蚀的特性而被广泛用于集装箱制造.但该钢在生产线上有时会形成反常的红色锈层.本文采用模拟氧化实验的方法研究了温度对SPAH钢红色锈的影响.利用金相、扫描电镜和能谱等手段研究了红色锈层的微观结构,利用有限元方法模拟了CSP生产线上工件不同部位的温度分布状况.研究发现,生产线上形成红色锈层的部位在生产过程中在560℃左右停留的时间比较长,说明560℃是形成红色锈层的特征温度. 相似文献
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Constitutive equation of annealed copper with high conductivity for deformation at high strain rates
After the discussion of a lot of constitutive equations, Zerilli-Armstrong constitutive equation (Z-A equation) was found to be a quasi-static equation. Based on this Z-A equation, a constitutive relations equation was constructed for dynamical calculation of fcc matels such as OFHC based on the thermal viscoplastic relations, where thermal dynamical parameters are related to the evolution of the microstructure of the deforming metals, and the variation of the density of the mobile dislocation was also considered. Data from the deformation of annealed copper were used to fit the parameters in the equation. The predicting results by using the constitutive equation are in good agreement with the experimental data. 相似文献
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Heavy duty engine valve head was prepared by Ni76Cr19A1Ti alloy. It was coated by cobalt-base alloy on the surface to promote its wear-resistance. Hardness tester, metallograph, scanning microscopy, energy spectrum and X-ray diffraction were used to analyze the mechanical properties, the microstructure of the welds and the coated layer of cobalt-base alloy. The results show that the grains are obviously coasened in the side of Ni76Cr19A1Ti alloy in the welds and it contains a typical dentritic structure in the side cobalt-base alloy. It is found that micro-strain in weld is stronger than that in heat-effected-zone. Micro-strain in nickel-base alloy is stronger than that cobalt-base alloy. There are not obvious imperfects in the weld. Hardness in cobalt-base alloy is more than 390HV and the major carbides in cobalt-base alloy are Cr7C3 and W2C. 相似文献
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三层铝复合轧制的包覆率与各个工艺参数之间存在着非常复杂的非线性关系,难以用准确的解析式来表达。我们利用对非线性系统逼近能力很强的神经网络进行了建模,形成了相应的工艺参数知识库,能较为准确地对复合轧制后的包覆率进行预测。 相似文献
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1 INTRODUCTIONShock prestrainedcopperisoftenusedinexperi ments[1~ 3] forresearchofthepropertiesofdeforma tionandtheformationofadiabaticshearbondsofma terialsathighstrainrateowingtoitshighductility .Theshock prestrain processisusedtoenhancethecalorificcapaci… 相似文献
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对夹杂物与氧化铁皮压入导致的冷轧板的典型缺陷的形貌与形成原因进行了分析与研究,并进行了模拟轧制试验。研究结果表明,夹杂物所致的冷轧板主要缺陷中以连铸卷渣为主。连铸卷渣亦导致冷轧板表面的麻点(麻面)缺陷,形貌与氧化铁皮压入导致同类缺陷相近,但亦有区别。缺陷暴露规律的模拟轧制试验结果与实际缺陷的形貌有很好的一致性,为研究缺陷形成原因与演变规律的有效手段。对典型缺陷的取样分析并结合模拟轧制试验结果证明,连铸坯深层带状卷渣可导致冷轧板带状表面翘皮(夹层)缺陷,连铸坯深层块状卷渣可导致冷硬板中部穿裂,连铸至末机架前的辊道划伤导致氧化铁皮压入是冷轧板表面黑(灰)线(带)缺陷的形成原因之一。 相似文献
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采用75%KSCN+25%NaSCN+0.9%K3Fe(CN)6+0.1%K4Fe(CN)6+2.5%NH4SCN的盐浴,45钢为正极,高铬不锈钢为负极,190℃±5℃,1 V电压,20 min低温电解表面渗硫方法,在45钢表面形成10 μm FeS渗层,并且用M-2000型磨损试验机,金相技术、SEM及XRD等分析仪考察其摩擦性能。结果表明,采用低温电解工艺方法可以在45钢表面制备质量较好的FeS层,具有明显的减磨作用;干摩擦条件下,渗硫表面的摩擦系数是未渗硫表面的60%,在油润滑条件下,渗硫表面的摩擦系数为未渗硫表面的70%;在一定载荷范围内,随载荷的增大,FeS层减磨作用增加。 相似文献
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