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微合金元素对00Cr12NiTi铁素体不锈钢焊接接头HAZ组织及力学性能的影响 总被引:1,自引:1,他引:0
通过对比试验,研究了微合金元素对00Cr12NiTi铁素体不锈钢焊接接头HAZ金相组织及力学性能的影响.结果表明,适当降低钢的铁素体化元素,增加奥氏体化元素,以获得室温下更多的低碳马氏体,提高热影响区的力学性能;同时适当增加钛和铌的含量,它们可与镍形成金属间化合物,在钢中弥散析出,起到第二相强化和阻止焊接HAZ晶粒长大的作用.通过此种成分优化方法,在钢材成本增加较少的情况下大大改善了HAZ的组织并提高了其力学性能. 相似文献
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根据等温条件下的铁索体晶粒长大公式,推导出了焊接热影响区(HAZ)铁索体晶粒长大的动力学方程,并结合焊接热循环的数值分析结果对TCS不锈钢热影响区晶粒长大进行了预测.在此基础上,对复合焊新型焊接工艺条件下TCS不锈钢HAZ的晶粒长大情况进行了数值计算,得到了3种工艺参数下TCS不锈钢复合焊HAZ内的晶粒尺寸.基于TCS不锈钢复合焊接接头的金相图片,测量了HAZ内的平均晶粒尺寸,对数值模拟结果进行了验证.初步讨论了晶粒尺寸随热循环温度的长大情况和热循环温度差异对晶粒长大的影响规律. 相似文献
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对一种新型镍基耐蚀合金(X-2#)与304奥氏体不锈钢手工氩弧焊接接头进行拉伸性能和硬度的测试,并结合OM,SEM和EDS等手段,系统研究了焊接接头的组织和力学性能.结果表明,X-2#/304异种金属焊接母材晶粒尺寸为40~65 mm,有利于异种钢的焊接;X-2#合金一侧熔合区未发现焊接缺陷,而304奥氏体不锈钢一侧有铁素体析出,铁素体中富Cr贫Ni;重熔区附近与靠304奥氏体不锈钢一侧的热影响区晶粒长大严重.X-2#/304异种金属焊接接头热影响区的Vickers硬度最小.X-2#/304焊接接头室温拉伸断裂位置在焊缝区,而高温拉伸断裂位置在304奥氏体不锈钢基体.由于Al,W和Mo元素的强化作用,X-2#合金的高温力学性能优于304奥氏体不锈钢. 相似文献
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扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性. 相似文献
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论述了CAD技术中参数化设计的三种建模方法,重点介绍了基于特征的参数化建模原理。在此基础上,分析机械设计中的机构结构,归纳出其零件的几何特征构成。设计了机构CAD图形库,并提出了该图形库生成步骤和人机交互界面。 相似文献
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采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合. 相似文献
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C. Colinet 《Intermetallics》2003,11(11-12):1095
A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described. 相似文献
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O. N. Vlasova N. N. Korneeva V. I. Eremenko O. Kh. Fatkullin N. M. Semenova S. N. Petrova D. D. Vaulin 《Metal Science and Heat Treatment》1991,33(12):924-931
Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991. 相似文献